HCS12
Microcontrollers
freescale.com
MC9S12C Family
MC9S12GC Family
Reference Manual
MC9S12C128
Rev 01.24
05/2010
To provide the most up-to-date information, the revision of our documents on the World Wide Web will be
the most current. Your printed copy may be an earlier revision. To verify you have the latest information
available, refer to:
http://freescale.com/
A full list of family members and options is included in the appendices.
The following revision history table summarizes changes contained in this document.
This document contains information for all constituent modules, with the exception of the S12 CPU. For
S12 CPU information please refer to the CPU S12 Reference Manual.
Revision History
Date Revision
Level Description
June, 2005 01.14 New Book
July, 2005 01.15 Removed 16MHz option for 128K, 96K and 64K versions
Minor corrections following review
Oct, 2005 01.16
Added outstanding flash module descriptions
Added EPP package options
Corrected and Enhanced recommended PCB layouts
Dec, 2005 01.17 Added note to PIM block diagram figure
Dec, 2005 01.18 Added PIM rerouting information to 80-pin package diagram
Jan, 2006 01.19 Modified LVI levels in electrical parameter section
Corrected TSCR2 typo in timer register listing
Mar, 2006 01.20 Cleaned up Device Overview Section
May, 2006 01.21
Added 0M66G to PartID table
Added units to MSCAN timing parameter table
Corrected missing overbars on pin names
Dec, 2006 01.22
Corrected CRGFLG contents in register summary
Removed non existing part number options
Removed unintended symbol fonts from table A6
May, 2007 01.23 Updated ATD section
Corrected typos
May, 2010 01.24 Updated TIM section
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 3
Rev 01.24
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128) .17
Chapter 2 Port Integration Module (PIM9C32) . . . . . . . . . . . . . . . . . . . . .73
Chapter 3 Module Mapping Control (MMCV4) . . . . . . . . . . . . . . . . . . . .109
Chapter 4 Multiplexed External Bus Interface (MEBIV3) . . . . . . . . . . . .129
Chapter 5 Interrupt (INTV1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157
Chapter 6 Background Debug Module (BDMV4) . . . . . . . . . . . . . . . . . .165
Chapter 7 Debug Module (DBGV1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191
Chapter 8 Analog-to-Digital Converter (ATD10B8C) . . . . . . . . . . . . . . .223
Chapter 9 Clocks and Reset Generator (CRGV4) . . . . . . . . . . . . . . . . . .251
Chapter 10 Scalable Controller Area Network (S12MSCANV2) . . . . . . . .287
Chapter 11 Oscillator (OSCV2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .343
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) . . . . . . . . . . . . . . . . .347
Chapter 13 Serial Communications Interface (S12SCIV2) . . . . . . . . . . . .383
Chapter 14 Serial Peripheral Interface (SPIV3) . . . . . . . . . . . . . . . . . . . . .413
Chapter 15 Timer Module (TIM16B8CV1) . . . . . . . . . . . . . . . . . . . . . . . . .435
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) . . . . . . . . . . .463
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1) . . . . . . . . . . . . . . . . .471
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1) . . . . . . . . . . . . . . . . .503
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4) . . . . . . . . . . . . . . . . .537
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1) . . . . . . . . . . . . . . . . .575
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1) . . . . . . . . . . . . . .613
Appendix A Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . .647
Appendix B Emulation Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .679
Appendix C Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .681
Appendix D Derivative Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .685
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 5
Rev 01.24
Chapter 1
MC9S12C and MC9S12GC Device Overview (MC9S12C128)
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
1.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.2 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.2.1 Device Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.2.2 Detailed Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.2.3 Part ID Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
1.3 Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
1.3.1 Device Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
1.3.2 Signal Properties Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
1.3.3 Pin Initialization for 48- and 52-Pin LQFP Bond Out Versions . . . . . . . . . . . . . . . . . . . 49
1.3.4 Detailed Signal Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
1.3.5 Power Supply Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
1.4 System Clock Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
1.5 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
1.5.1 Chip Configuration Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
1.5.2 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
1.5.3 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
1.6 Resets and Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
1.6.1 Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
1.6.2 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
1.7 Device Specific Information and Module Dependencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
1.7.1 PPAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
1.7.2 BDM Alternate Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
1.7.3 Extended Address Range Emulation Implications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
1.7.4 VREGEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
1.7.5 VDD1, VDD2, VSS1, VSS2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
1.7.6 Clock Reset Generator And VREG Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
1.7.7 Analog-to-Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
1.7.8 MODRR Register Port T And Port P Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
1.7.9 Port AD Dependency On PIM And ATD Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
1.8 Recommended Printed Circuit Board Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Chapter 2
Port Integration Module (PIM9C32) Block Description
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
2.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
6 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.1.2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
2.2 Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
2.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
2.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
2.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
2.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
2.4.1 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
2.4.2 Port Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
2.4.3 Port A, B, E and BKGD Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.4.4 External Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.4.5 Low Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.5 Initialization Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.5.1 Reset Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
2.6.1 Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
2.6.2 Recovery from STOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
2.7 Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Chapter 3
Module Mapping Control (MMCV4) Block Description
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
3.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
3.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
3.4.1 Bus Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
3.4.2 Address Decoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
3.4.3 Memory Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Chapter 4
Multiplexed External Bus Interface (MEBIV3)
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
4.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
4.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
4.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
4.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
4.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
4.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
4.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
4.4.1 Detecting Access Type from External Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
4.4.2 Stretched Bus Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 7
Rev 01.24
4.4.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
4.4.4 Internal Visibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
4.4.5 Low-Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Chapter 5
Interrupt (INTV1) Block Description
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
5.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
5.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
5.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
5.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
5.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
5.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
5.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
5.4.1 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
5.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
5.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
5.6.1 Interrupt Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
5.6.2 Highest Priority I-Bit Maskable Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
5.6.3 Interrupt Priority Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
5.7 Exception Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Chapter 6
Background Debug Module (BDMV4) Block Description
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
6.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
6.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
6.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
6.2.1 BKGD — Background Interface Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
6.2.2 TAGHI — High Byte Instruction Tagging Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
6.2.3 TAGLO — Low Byte Instruction Tagging Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
6.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
6.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
6.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
6.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
6.4.1 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
6.4.2 Enabling and Activating BDM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
6.4.3 BDM Hardware Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
6.4.4 Standard BDM Firmware Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
6.4.5 BDM Command Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
6.4.6 BDM Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
6.4.7 Serial Interface Hardware Handshake Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
6.4.8 Hardware Handshake Abort Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
6.4.9 SYNC — Request Timed Reference Pulse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
8 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
6.4.10 Instruction Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
6.4.11 Instruction Tagging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
6.4.12 Serial Communication Time-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
6.4.13 Operation in Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
6.4.14 Operation in Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Chapter 7
Debug Module (DBGV1) Block Description
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
7.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
7.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
7.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
7.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
7.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
7.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
7.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
7.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
7.4.1 DBG Operating in BKP Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
7.4.2 DBG Operating in DBG Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
7.4.3 Breakpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
7.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
7.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Chapter 8
Analog-to-Digital Converter (ATD10B8C)
Block Description
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
8.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
8.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
8.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
8.2 Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.1 AN7 / ETRIG / PAD7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.2 AN6 / PAD6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.3 AN5 / PAD5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.4 AN4 / PAD4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.5 AN3 / PAD3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.6 AN2 / PAD2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.7 AN1 / PAD1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.8 AN0 / PAD0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.9 VRH, VRL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.2.10 VDDA, VSSA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
8.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
8.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
8.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 9
Rev 01.24
8.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
8.4.1 Analog Sub-block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
8.4.2 Digital Sub-block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
8.5 Initialization/Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
8.5.1 Setting up and starting an A/D conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
8.5.2 Aborting an A/D conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
8.6 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
8.7 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Chapter 9
Clocks and Reset Generator (CRGV4) Block Description
9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
9.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
9.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
9.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
9.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
9.2.1 VDDPLL, VSSPLL — PLL Operating Voltage, PLL Ground . . . . . . . . . . . . . . . . . . . . . . 253
9.2.2 XFC — PLL Loop Filter Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
9.2.3 RESET — Reset Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
9.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
9.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
9.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
9.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
9.4.1 Phase Locked Loop (PLL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
9.4.2 System Clocks Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
9.4.3 Clock Monitor (CM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
9.4.4 Clock Quality Checker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
9.4.5 Computer Operating Properly Watchdog (COP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
9.4.6 Real-Time Interrupt (RTI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
9.4.7 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
9.4.8 Low-Power Operation in Run Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
9.4.9 Low-Power Operation in Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
9.4.10 Low-Power Operation in Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
9.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
9.5.1 Clock Monitor Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
9.5.2 Computer Operating Properly Watchdog (COP) Reset . . . . . . . . . . . . . . . . . . . . . . . . . 284
9.5.3 Power-On Reset, Low Voltage Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
9.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
9.6.1 Real-Time Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
9.6.2 PLL Lock Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
9.6.3 Self-Clock Mode Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
10 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Chapter 10
Freescale’s Scalable Controller Area Network (S12MSCANV2)
10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
10.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
10.1.2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
10.1.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
10.1.4 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
10.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
10.2.1 RXCAN — CAN Receiver Input Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
10.2.2 TXCAN — CAN Transmitter Output Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
10.2.3 CAN System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
10.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
10.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
10.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
10.3.3 Programmer’s Model of Message Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
10.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
10.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
10.4.2 Message Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
10.4.3 Identifier Acceptance Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
10.4.4 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
10.4.5 Low-Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
10.4.6 Reset Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
10.4.7 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
10.5 Initialization/Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
10.5.1 MSCAN initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Chapter 11
Oscillator (OSCV2) Block Description
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
11.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
11.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
11.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
11.2.1 VDDPLL and VSSPLL — PLL Operating Voltage, PLL Ground . . . . . . . . . . . . . . . . . . . 344
11.2.2 EXTAL and XTAL — Clock/Crystal Source Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
11.2.3 XCLKS — Colpitts/Pierce Oscillator Selection Signal . . . . . . . . . . . . . . . . . . . . . . . . . 345
11.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
11.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
11.4.1 Amplitude Limitation Control (ALC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
11.4.2 Clock Monitor (CM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
11.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
Chapter 12
Pulse-Width Modulator (PWM8B6CV1) Block Description
12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 11
Rev 01.24
12.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
12.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
12.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
12.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
12.2.1 PWM5 — Pulse Width Modulator Channel 5 Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
12.2.2 PWM4 — Pulse Width Modulator Channel 4 Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
12.2.3 PWM3 — Pulse Width Modulator Channel 3 Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
12.2.4 PWM2 — Pulse Width Modulator Channel 2 Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
12.2.5 PWM1 — Pulse Width Modulator Channel 1 Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
12.2.6 PWM0 — Pulse Width Modulator Channel 0 Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
12.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
12.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
12.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
12.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
12.4.1 PWM Clock Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
12.4.2 PWM Channel Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
12.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
12.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
Chapter 13
Serial Communications Interface (S12SCIV2)
Block Description
13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
13.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
13.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
13.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384
13.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385
13.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385
13.2.1 TXD-SCI Transmit Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385
13.2.2 RXD-SCI Receive Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385
13.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
13.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
13.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394
13.4.1 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395
13.4.2 Baud Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396
13.4.3 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
13.4.4 Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400
13.4.5 Single-Wire Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
13.4.6 Loop Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
13.5 Initialization Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
13.5.1 Reset Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
13.5.2 Interrupt Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410
13.5.3 Recovery from Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
12 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Chapter 14
Serial Peripheral Interface (SPIV3) Block Description
14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
14.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
14.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
14.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
14.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
14.2.1 MOSI — Master Out/Slave In Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
14.2.2 MISO — Master In/Slave Out Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
14.2.3 SS — Slave Select Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
14.2.4 SCK — Serial Clock Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
14.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
14.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
14.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
14.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
14.4.1 Master Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424
14.4.2 Slave Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
14.4.3 Transmission Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426
14.4.4 SPI Baud Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429
14.4.5 Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
14.4.6 Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431
14.4.7 Operation in Run Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432
14.4.8 Operation in Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432
14.4.9 Operation in Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432
14.5 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
14.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
14.6.1 MODF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
14.6.2 SPIF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
14.6.3 SPTEF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
Chapter 15
Timer Module (TIM16B8CV1) Block Description
15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435
15.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435
15.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436
15.1.3 Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436
15.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438
15.2.1 IOC7 — Input Capture and Output Compare Channel 7 Pin . . . . . . . . . . . . . . . . . . . . 438
15.2.2 IOC6 — Input Capture and Output Compare Channel 6 Pin . . . . . . . . . . . . . . . . . . . . 438
15.2.3 IOC5 — Input Capture and Output Compare Channel 5 Pin . . . . . . . . . . . . . . . . . . . . 438
15.2.4 IOC4 — Input Capture and Output Compare Channel 4 Pin . . . . . . . . . . . . . . . . . . . . 438
15.2.5 IOC3 — Input Capture and Output Compare Channel 3 Pin . . . . . . . . . . . . . . . . . . . . 438
15.2.6 IOC2 — Input Capture and Output Compare Channel 2 Pin . . . . . . . . . . . . . . . . . . . . 439
15.2.7 IOC1 — Input Capture and Output Compare Channel 1 Pin . . . . . . . . . . . . . . . . . . . . 439
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 13
Rev 01.24
15.2.8 IOC0 — Input Capture and Output Compare Channel 0 Pin . . . . . . . . . . . . . . . . . . . . 439
15.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
15.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
15.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
15.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457
15.4.1 Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458
15.4.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459
15.4.3 Output Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459
15.4.4 Pulse Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460
15.4.5 Event Counter Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460
15.4.6 Gated Time Accumulation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
15.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
15.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
15.6.1 Channel [7:0] Interrupt (C[7:0]F) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
15.6.2 Pulse Accumulator Input Interrupt (PAOVI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462
15.6.3 Pulse Accumulator Overflow Interrupt (PAOVF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462
15.6.4 Timer Overflow Interrupt (TOF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462
Chapter 16
Dual Output Voltage Regulator (VREG3V3V2)
Block Description
16.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463
16.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463
16.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463
16.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464
16.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
16.2.1 VDDR — Regulator Power Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
16.2.2 VDDA, VSSA — Regulator Reference Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
16.2.3 VDD, VSS — Regulator Output1 (Core Logic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
16.2.4 VDDPLL, VSSPLL — Regulator Output2 (PLL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
16.2.5 VREGEN — Optional Regulator Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
16.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
16.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
16.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467
16.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467
16.4.1 REG — Regulator Core . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
16.4.2 Full-Performance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
16.4.3 Reduced-Power Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
16.4.4 LVD — Low-Voltage Detect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
16.4.5 POR — Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
16.4.6 LVR — Low-Voltage Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
16.4.7 CTRL — Regulator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
16.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
16.5.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
16.5.2 Low-Voltage Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
14 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
16.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
16.6.1 LVI — Low-Voltage Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
Chapter 17
16 Kbyte Flash Module (S12FTS16KV1)
17.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
17.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
17.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
17.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472
17.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472
17.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472
17.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473
17.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473
17.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475
17.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486
17.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486
17.4.2 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500
17.4.3 Flash Module Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500
17.4.4 Flash Reset Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502
17.4.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502
Chapter 18
32 Kbyte Flash Module (S12FTS32KV1)
18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503
18.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503
18.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503
18.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504
18.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504
18.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504
18.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
18.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
18.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508
18.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520
18.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520
18.4.2 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534
18.4.3 Flash Module Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534
18.4.4 Flash Reset Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536
18.4.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536
Chapter 19
64 Kbyte Flash Module (S12FTS64KV4)
19.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537
19.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537
19.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 15
Rev 01.24
19.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538
19.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538
19.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539
19.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539
19.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539
19.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545
19.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557
19.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557
19.4.2 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571
19.4.3 Flash Module Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571
19.4.4 Flash Reset Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
19.4.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
Chapter 20
96 Kbyte Flash Module (S12FTS96KV1)
20.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575
20.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575
20.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575
20.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576
20.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576
20.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577
20.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577
20.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577
20.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583
20.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595
20.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595
20.4.2 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 609
20.4.3 Flash Module Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 609
20.4.4 Flash Reset Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611
20.4.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611
Chapter 21
128 Kbyte Flash Module (S12FTS128K1V1)
21.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613
21.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613
21.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613
21.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 614
21.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 614
21.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 614
21.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615
21.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615
21.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 618
21.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 630
21.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 630
16 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
21.4.2 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644
21.4.3 Flash Module Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644
21.4.4 Flash Reset Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646
21.4.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646
Appendix A
Electrical Characteristics
A.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 647
A.2 ATD Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 658
A.3 MSCAN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663
A.4 Reset, Oscillator and PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663
A.5 NVM, Flash, and EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669
A.6 SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 673
A.7 Voltage Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677
Appendix B
Emulation Information
B.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679
Appendix C
Package Information
C.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681
Appendix D
Derivative Differences
Appendix E
Ordering Information
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 17
Rev 01.24
Chapter 1
MC9S12C and MC9S12GC Device Overview (MC9S12C128)
1.1 Introduction
The MC9S12C-Family / MC9S12GC-Family are 48/52/80 pin Flash-based MCU families, which deliver
the power and flexibility of the 16-bit core to a whole new range of cost and space sensitive, general
purpose industrial and automotive network applications. All MC9S12C-Family / MC9S12GC-Family
members feature standard on-chip peripherals including a 16-bit central processing unit (CPU12), up to
128K bytes of Flash EEPROM, up to 4K bytes of RAM, an asynchronous serial communications interface
(SCI), a serial peripheral interface (SPI), an 8-channel 16-bit timer module (TIM), a 6-channel 8-bit pulse
width modulator (PWM), an 8-channel, 10-bit analog-to-digital converter (ADC).
The MC9S12C128-Family members also feature a CAN 2.0 A, B software compatible module
(MSCAN12).
All MC9S12C-Family / MC9S12GC-Family devices feature full 16-bit data paths throughout. The
inclusion of a PLL circuit allows power consumption and performance to be adjusted to suit operational
requirements. In addition to the I/O ports available in each module, up to 10 dedicated I/O port bits are
available with wake-up capability from stop or wait mode. The devices are available in 48-, 52-, and 80-
pin QFP packages, with the 80-pin version pin compatible to the HCS12 A, B, and D Family derivatives.
1.1.1 Features
• 16-bit HCS12 core:
— HCS12 CPU
– Upward compatible with M68HC11 instruction set
– Interrupt stacking and programmer’s model identical to M68HC11
– Instruction queue
– Enhanced indexed addressing
— MMC (memory map and interface)
— INT (interrupt control)
— BDM (background debug mode)
— DBG12 (enhanced debug12 module, including breakpoints and change-of-flow trace buffer)
— MEBI (multiplexed expansion bus interface) available only in 80-pin package version
• Wake-up interrupt inputs:
— Up to 12 port bits available for wake up interrupt function with digital filtering
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
18 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
• Memory options:
— 16K or 32Kbyte Flash EEPROM (erasable in 512-byte sectors)
64K, 96K, or 128Kbyte Flash EEPROM (erasable in 1024-byte sectors)
— 1K, 2K or 4K Byte RAM
• Analog-to-digital converters:
— One 8-channel module with 10-bit resolution
— External conversion trigger capability
• Available on MC9S12C Family:
— One 1M bit per second, CAN 2.0 A, B software compatible module
— Five receive and three transmit buffers
— Flexible identifier filter programmable as 2 x 32 bit, 4 x 16 bit, or 8 x 8 bit
— Four separate interrupt channels for Rx, Tx, error, and wake-up
— Low-pass filter wake-up function
— Loop-back for self test operation
• Timer module (TIM):
— 8-channel timer
— Each channel configurable as either input capture or output compare
— Simple PWM mode
— Modulo reset of timer counter
— 16-bit pulse accumulator
— External event counting
— Gated time accumulation
• PWM module:
— Programmable period and duty cycle
— 8-bit 6-channel or 16-bit 3-channel
— Separate control for each pulse width and duty cycle
— Center-aligned or left-aligned outputs
— Programmable clock select logic with a wide range of frequencies
— Fast emergency shutdown input
• Serial interfaces:
— One asynchronous serial communications interface (SCI)
— One synchronous serial peripheral interface (SPI)
• CRG (clock reset generator module)
— Windowed COP watchdog
— Real time interrupt
— Clock monitor
— Pierce or low current Colpitts oscillator
— Phase-locked loop clock frequency multiplier
— Limp home mode in absence of external clock
— Low power 0.5MHz to 16MHz crystal oscillator reference clock
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 19
Rev 01.24
• Operating frequency:
— 32MHz equivalent to 16MHz bus speed for single chip
— 32MHz equivalent to 16MHz bus speed in expanded bus modes
— Option of 9S12C Family: 50MHz equivalent to 25MHz bus speed
— All 9S12GC Family members allow a 50MHz operating frequency.
• Internal 2.5V regulator:
— Supports an input voltage range from 2.97V to 5.5V
— Low power mode capability
— Includes low voltage reset (LVR) circuitry
— Includes low voltage interrupt (LVI) circuitry
• 48-pin LQFP, 52-pin LQFP, or 80-pin QFP package:
— Up to 58 I/O lines with 5V input and drive capability (80-pin package)
— Up to 2 dedicated 5V input only lines (IRQ, XIRQ)
— 5V 8 A/D converter inputs and 5V I/O
• Development support:
— Single-wire background debug™ mode (BDM)
— On-chip hardware breakpoints
— Enhanced DBG12 debug features
1.1.2 Modes of Operation
User modes (expanded modes are only available in the 80-pin package version).
• Normal and emulation operating modes:
— Normal single-chip mode
— Normal expanded wide mode
— Normal expanded narrow mode
— Emulation expanded wide mode
— Emulation expanded narrow mode
• Special operating modes:
— Special single-chip mode with active background debug mode
— Special test mode (Freescale use only)
— Special peripheral mode (Freescale use only)
• Low power modes:
— Stop mode
— Pseudo stop mode
— Wait mode
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
20 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.1.3 Block Diagram
Figure 1-1. MC9S12C-Family / MC9S12GC-Family Block Diagram
16K, 32K, 64K, 96K, 128K Byte Flash
1K, 2K, 4K Byte RAM
SCI
VDDR
VDDA
VSSA
VRH
VRL
ATD AN2
AN6
AN0
AN7
AN1
AN3
AN4
AN5
PAD3
PAD4
PAD5
PAD6
PAD7
PAD0
PAD1
PAD2
IOC2
IOC6
IOC0
IOC7
IOC1
IOC3
IOC4
IOC5
PT3
PT4
PT5
PT6
PT7
PT0
PT1
PT2
RXD
TXD
SCK
MISO
PS3
PS0
PS1
PS2
SS
SPI
PTAD
PTT
DDRT
PTS
DDRS
Voltage Regulator
VDD1
VSS1
PWM
Signals shown in Bold are not available on the 52 or 48 Pin Package
DDRAD
VDDA
VSSA
Timer
Module
VDDX
VSSX
VRH
VRL
VSSR
RESET
EXTAL
XTAL
BKGD
R/W
MODB/IPIPE1
XIRQ
NOACC/XCLKS
System
Integration
Module
(SIM)
HCS12
Periodic Interrupt
COP Watchdog
Clock Monitor
PLL
VSSPLL
XFC
VDDPLL
Multiplexed Address/Data Bus
Multiplexed
Wide Bus
IRQ
LSTRB/TAGLO
ECLK
MODA/IPIPE0
PA4
PA3
PA 2
PA 1
PA0
PA7
PA6
PA5
TEST/VPP
ADDR12
ADDR11
ADDR10
ADDR9
ADDR8
ADDR15
ADDR14
ADDR13
DATA12
DATA11
DATA10
DATA9
DATA8
DATA15
DATA14
DATA13
PB4
PB3
PB2
PB1
PB0
PB7
PB6
PB5
ADDR4
ADDR3
ADDR2
ADDR1
ADDR0
ADDR7
ADDR6
ADDR5
DATA4
DATA3
DATA2
DATA1
DATA0
DATA7
DATA6
DATA5
PE3
PE4
PE5
PE6
PE7
PE0
PE1
PE2
DDRA DDRB
PTA PTB
DDRE
PTE
BDM
VDD2
VSS2
Signals shown in Bold Italic are available in the 52, but not the 48 Pin Package
CPU
PM3
PM4
PM5
PM0
PM1
PM2
PTM
DDRM
PW2
PW0
PW1
PW3
PW4
PW5
PP3
PP4
PP5
PP6
PP7
PP0
PP1
PP2
PTP
DDRP
PJ6
PJ7
PTJ
DDRJ
VDD1,2
VSS1,2
VDDX
VSSX
Internal Logic 2.5V
VDDPLL
VSSPLL
PLL 2.5V
I/O Driver 5V
VDDA
VSSA
A/D Converter 5V
VDDR
VSSR
Voltage Regulator 5V & I/O
VRL is bonded internally to VSSA
for 52- and 48-Pin packages
MOSI
Module
MUX
Keypad Interrupt
Key Int
MODC/TAGHI
MSCAN is not available on the
9S12GC Family Members
Clock and
Reset
Generation
Module
MSCAN TXCAN
RXCAN
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 21
Rev 01.24
1.2 Memory Map and Registers
1.2.1 Device Memory Map
Table 1-1 shows the device register map after reset. Figure 1-2 through Figure 1-6 illustrate the full device
memory map.
Table 1-1. Device Register Map Overview
Address Module Size
0x0000–0x0017 Core (ports A, B, E, modes, inits, test) 24
0x0018 Reserved 1
0x0019 Voltage regulator (VREG) 1
0x001A–0x001B Device ID register 2
0x001C–0x001F Core (MEMSIZ, IRQ, HPRIO) 4
0x0020–0x002F Core (DBG) 16
0x0030–0x0033 Core (PPAGE(1))
1. External memory paging is not supported on this device (Section 1.7.1, “PPAGE”).
4
0x0034–0x003F Clock and reset generator (CRG) 12
0x0040–0x006F Standard timer module (TIM) 48
0x0070–0x007F Reserved 16
0x0080–0x009F Analog-to-digital converter (ATD) 32
0x00A0–0x00C7 Reserved 40
0x00C8–0x00CF Serial communications interface (SCI) 8
0x00D0–0x00D7 Reserved 8
0x00D8–0x00DF Serial peripheral interface (SPI) 8
0x00E0–0x00FF Pulse width modulator (PWM) 32
0x0100–0x010F Flash control register 16
0x0110–0x013F Reserved 48
0x0140–0x017F Scalable controller area network (MSCAN)(2)
2. Not available on MC9S12GC Family devices
64
0x0180–0x023F Reserved 192
0x0240–0x027F Port integration module (PIM) 64
0x0280–0x03FF Reserved 384
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
22 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-2. MC9S12C128 and MC9S12GC128 User Configurable Memory Map
0x0000
0xFFFF
0xC000
0x8000
0x4000
0x0400
0xFF00
EXT
NORMAL
SINGLE CHIP
EXPANDED SPECIAL
SINGLE CHIP
VECTORS
VECTORS
0xFF00
0xFFFF
BDM
(If Active)
0xC000
0xFFFF
16K Fixed Flash EEPROM
0x8000
0xBFFF
16K Page Window
8 * 16K Flash EEPROM Pages
0x4000
0x7FFF
16K Fixed Flash EEPROM
0x3000
0x3FFF
0x0000
0x03FF
1K Register Space
Mappable to any 2K Boundary
Mappable to any 4K Boundary
4K Bytes RAM
0x3000
The figure shows a useful map, which is not the map out of reset. After reset the map is:
0x0000–0x03FF: Register Space
0x0000–0x0FFF: 4K RAM (only 3K visible 0x0400–0x0FFF)
0x0000
0x3FFF
16K Fixed Flash EEPROM
VECTORS
Flash erase sector size is 1024 bytes
PAGE MAP
0x003D
0x003E
0x003F
PPAGE
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 23
Rev 01.24
Figure 1-3. MC9S12C96 and MC9S12GC96 User Configurable Memory Map
0x0000
0xFFFF
0xC000
0x8000
0x4000
0x0400
0xFF00
EXT
NORMAL
SINGLE CHIP
EXPANDED SPECIAL
SINGLE CHIP
VECTORS
VECTORS
0xFF00
0xFFFF
BDM
(If Active)
0xC000
0xFFFF
16K Fixed Flash EEPROM
0x8000
0xBFFF
16K Page Window
6 * 16K Flash EEPROM Pages
0x4000
0x7FFF
16K Fixed Flash EEPROM
0x3000
0x3FFF
0x0000
0x03FF
1K Register Space
Mappable to any 2K Boundary
Mappable to any 4K Boundary
4K Bytes RAM
0x3000
The figure shows a useful map, which is not the map out of reset. After reset the map is:
0x0000–0x03FF: Register Space
0x0000–0x0FFF: 4K RAM (only 3K visible 0x0400–0x0FFF)
0x0000
0x3FFF
16K Fixed Flash EEPROM
VECTORS
Flash erase sector size is 1024 bytes
PAGE MAP
0x003D
0x003E
0x003F
PPAGE
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
24 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-4. MC9S12C64 and MC9S12GC64 User Configurable Memory Map
0x0000
0xFFFF
0xC000
0x8000
0x4000
0x0400
0xFF00
EXT
NORMAL
SINGLE CHIP
EXPANDED SPECIAL
SINGLE CHIP
VECTORS
VECTORS
0xFF00
0xFFFF
BDM
(If Active)
0xC000
0xFFFF
16K Fixed Flash EEPROM
0x8000
0xBFFF
16K Page Window
4 * 16K Flash EEPROM Pages
0x4000
0x7FFF
16K Fixed Flash EEPROM
0x3000
0x3FFF
0x0000
0x03FF
1K Register Space
Mappable to any 2K Boundary
Mappable to any 4K Boundary
4K Bytes RAM
0x3000
The figure shows a useful map, which is not the map out of reset. After reset the map is:
0x0000–0x03FF: Register space
0x0000–0x0FFF: 4K RAM (only 3K visible 0x0400–0x0FFF)
0x0000
0x3FFF
16K Fixed Flash EEPROM
VECTORS
Flash erase sector size is 1024 Bytes
PAGE MAP
0x003E
0x003F
PPAGE
0x003D
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 25
Rev 01.24
Figure 1-5. MC9S12C32 and MC9S12GC32 User Configurable Memory Map
0x0000
0xFFFF
0xC000
0x8000
0x4000
0x0400
0xFF00
EXT
NORMAL
SINGLE CHIP
EXPANDED SPECIAL
SINGLE CHIP
VECTORS
VECTORS
0xFF00
0xFFFF
BDM
(If Active)
0xC000
0xFFFF
16K Fixed Flash EEPROM
0x8000
0xBFFF
16K Page Window
2 * 16K Flash EEPROM Pages
0x3800
0x3FFF
0x0000
0x03FF
1K Register Space
Mappable to any 2K Boundary
Mappable to any 2K Boundary
2K Bytes RAM
0x3800
The figure shows a useful map, which is not the map out of reset. After reset the map is:
0x0000–0x03FF: Register space
0x0800–0x0FFF: 2K RAM
VECTORS
Flash erase sector size is 512 bytes
PAGE MAP
0x003E
0x003F
PPAGE
The flash page 0x003E is visible at 0x4000–0x7FFF in the memory map if ROMHM = 0.
In the figure ROMHM = 1 removing page 0x003E from 0x4000–0x7FFF.
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
26 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-6. MC9S12GC16 User Configurable Memory Map
0x0000
0xFFFF
0xC000
0x8000
0x4000
0x0400
0xFF00
EXT
NORMAL
SINGLE CHIP
EXPANDED SPECIAL
SINGLE CHIP
VECTORS
VECTORS
0xFF00
0xFFFF
BDM
(If Active)
0xC000
0xFFFF
16K Fixed Flash EEPROM
0x3C00
0x3FFF
0x0000
0x03FF
1K Register Space
Mappable to any 2K Boundary
Mappable to any 2K Boundary
1K Bytes RAM
0x3C00
The figure shows a useful map, which is not the map out of reset. After reset the map is:
0x0000–0x03FF: Register Space
0x0C00–0x0FFF: 1K RAM
VECTORS
The 16K flash array page 0x003F is also visible in the PPAGE window when PPAGE register contents are odd.
PAGE MAP
0x003F
PPAGE
0x8000
0xBFFF
16K Page Window
Flash Erase Sector Size is 512 Bytes
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 27
Rev 01.24
1.2.2 Detailed Register Map
The detailed register map of the MC9S12C128
is listed in address order below.
0x0000–0x000F MEBI Map 1 of 3 (HCS12 Multiplexed External Bus Interface)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0000 PORTA Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0001 PORTB Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0002 DDRA Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0003 DDRB Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0004 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0005 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0006 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0007 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0008 PORTE Read: Bit 7 6 5 4 3 2 Bit 1 Bit 0
Write:
0x0009 DDRE Read: Bit 7 6 5 4 3 Bit 2 00
Write:
0x000A PEAR Read: NOACCE 0PIPOE NECLK LSTRE RDWE 00
Write:
0x000B MODE Read: MODC MODB MODA 0IVIS 0EMK EME
Write:
0x000C PUCR Read: PUPKE 00
PUPEE 00
PUPBE PUPAE
Write:
0x000D RDRIV Read: RDPK 00
RDPE 00
RDPB RDPA
Write:
0x000E EBICTL Read: 0 0 0 0 0 0 0 ESTR
Write:
0x000F Reserved Read: 0 0 0 0 0 0 0 0
Write:
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
28 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x0010–0x0014 MMC Map 1 of 4 (HCS12 Module Mapping Control)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0010 INITRM Read: RAM15 RAM14 RAM13 RAM12 RAM11 00
RAMHAL
Write:
0x0011 INITRG Read: 0 REG14 REG13 REG12 REG11 000
Write:
0x0012 INITEE Read: EE15 EE14 EE13 EE12 EE11 00
EEON
Write:
0x0013 MISC Read: 0 0 0 0 EXSTR1 EXSTR0 ROMHM ROMON
Write:
0x0014 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0015–0x0016 INT Map 1 of 2 (HCS12 Interrupt)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0015 ITCR Read: 0 0 0 WRINT ADR3 ADR2 ADR1 ADR0
Write:
0x0016 ITEST Read: INTE INTC INTA INT8 INT6 INT4 INT2 INT0
Write:
0x0017–0x0017 MMC Map 2 of 4 (HCS12 Module Mapping Control)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0017 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0018–0x0018 Miscellaneous Peripherals (Device User Guide)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0018 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0019–0x0019 VREG3V3 (Voltage Regulator)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
$0019 VREGCTRL Read: 0 0 0 0 0 LVDS LVIE LVIF
Write:
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 29
Rev 01.24
0x001A–0x001B Miscellaneous Peripherals (Device User Guide)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x001A PARTIDH Read: ID15 ID14 ID13 ID12 ID11 ID10 ID9 ID8
Write:
0x001B PARTIDL Read: ID7 ID6 ID5 ID4 ID3 ID2 ID1 ID0
Write:
0x001C–0x001D MMC Map 3 of 4 (HCS12 Module Mapping Control, Device User Guide)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x001C MEMSIZ0 Read: reg_sw0 0 eep_sw1 eep_sw0 0 ram_sw2 ram_sw1 ram_sw0
Write:
0x001D MEMSIZ1 Read: rom_sw1 rom_sw0 0 0 0 0 pag_sw1 pag_sw0
Write:
0x001E–0x001E MEBI Map 2 of 3 (HCS12 Multiplexed External Bus Interface)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x001E INTCR Read: IRQE IRQEN 000000
Write:
0x001F–0x001F INT Map 2 of 2 (HCS12 Interrupt)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x001F HPRIO Read: PSEL7 PSEL6 PSEL5 PSEL4 PSEL3 PSEL2 PSEL1 0
Write:
0x0020–0x002F DBG (Including BKP) Map 1 of 1 (HCS12 Debug)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0020 DBGC1 Read: DBGEN ARM TRGSEL BEGIN DBGBRK 0CAPMOD
Write:
0x0021 DBGSC Read: AF BF CF 0 TRG
Write:
0x0022 DBGTBH Read: Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
Write:
0x0023 DBGTBL Read: Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Write:
0x0024 DBGCNT Read: TBF 0 CNT
Write:
0x0025 DBGCCX Read: PAGSEL EXTCMP
Write:
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
30 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x0026 DBGCCH Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0027 DBGCCL Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0028 DBGC2 Read: BKABEN FULL BDM TAGAB BKCEN TAGC RWCEN RWC
BKPCT0 Write:
0x0029 DBGC3 Read: BKAMBH BKAMBL BKBMBH BKBMBL RWAEN RWA RWBEN RWB
BKPCT1 Write:
0x002A DBGCAX Read: PAGSEL EXTCMP
BKP0X Write:
0x002B DBGCAH Read: Bit 15 14 13 12 11 10 9 Bit 8
BKP0H Write:
0x002C DBGCAL Read: Bit 7 6 5 4 3 2 1 Bit 0
BKP0L Write:
0x002D DBGCBX Read: PAGSEL EXTCMP
BKP1X Write:
0x002E DBGCBH Read: Bit 15 14 13 12 11 10 9 Bit 8
BKP1H Write:
0x002F DBGCBL Read: Bit 7 6 5 4 3 2 1 Bit 0
BKP1L Write:
0x0030–0x0031 MMC Map 4 of 4 (HCS12 Module Mapping Control)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0030 PPAGE Read: 0 0 PIX5 PIX4 PIX3 PIX2 PIX1 PIX0
Write:
0x0031 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0032–0x0033 MEBI Map 3 of 3 (HCS12 Multiplexed External Bus Interface)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0032 PORTK(1)
1. Only applicable in special emulation-only bond outs, for emulation of extended memory map.
Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0033 DDRK1Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
$0032 Reserved Read: 0 0 0 0 0 0 0 0
Write:
$0033 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0020–0x002F DBG (Including BKP) Map 1 of 1 (HCS12 Debug) (continued)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 31
Rev 01.24
ep0x0040-0x006F TIM
0x0034–0x003F CRG (Clock and Reset Generator)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0034 SYNR Read: 0 0 SYN5 SYN4 SYN3 SYN2 SYN1 SYN0
Write:
0x0035 REFDV Read: 0 0 0 0 REFDV3 REFDV2 REFDV1 REFDV0
Write:
0x0036 CTFLG
TEST ONLY
Read: TOUT7 TOUT6 TOUT5 TOUT4 TOUT3 TOUT2 TOUT1 TOUT0
Write:
0x0037 CRGFLG Read: RTIF PORF LVRF LOCKIF LOCK TRACK SCMIF SCM
Write:
0x0038 CRGINT Read: RTIE 00
LOCKIE 00
SCMIE 0
Write:
0x0039 CLKSEL Read: PLLSEL PSTP SYSWAI ROAWAI PLLWAI CWAI RTIWAI COPWAI
Write:
0x003A PLLCTL Read: CME PLLON AUTO ACQ 0PRE PCE SCME
Write:
0x003B RTICTL Read: 0 RTR6 RTR5 RTR4 RTR3 RTR2 RTR1 RTR0
Write:
0x003C COPCTL Read: WCOP RSBCK 000
CR2 CR1 CR0
Write:
0x003D FORBYP
TEST ONLY
Read: RTIBYP COPBYP 0PLLBYP 00
FCM 0
Write:
0x003E CTCTL
TEST ONLY
Read: TCTL7 TCTL6 TCTL5 TCTL4 TCLT3 TCTL2 TCTL1 TCTL0
Write:
0x003F ARMCOP Read: 0 0 0 0 0 0 0 0
Write: Bit 7 6 5 4 3 2 1 Bit 0
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0040 TIOS Read: IOS7 IOS6 IOS5 IOS4 IOS3 IOS2 IOS1 IOS0
Write:
0x0041 CFORC Read: 0 0 0 0 0 0 0 0
Write: FOC7 FOC6 FOC5 FOC4 FOC3 FOC2 FOC1 FOC0
0x0042 OC7M Read: OC7M7 OC7M6 OC7M5 OC7M4 OC7M3 OC7M2 OC7M1 OC7M0
Write:
0x0043 OC7D Read: OC7D7 OC7D6 OC7D5 OC7D4 OC7D3 OC7D2 OC7D1 OC7D0
Write:
0x0044 TCNT (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0045 TCNT (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0046 TSCR1 Read: TEN TSWAI TSFRZ TFFCA 0000
Write:
0x0047 TTOV Read: TOV7 TOV6 TOV5 TOV4 TOV3 TOV2 TOV1 TOV0
Write:
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
32 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x0048 TCTL1 Read: OM7 OL7 OM6 OL6 OM5 OL5 OM4 OL4
Write:
0x0049 TCTL2 Read: OM3 OL3 OM2 OL2 OM1 OL1 OM0 OL0
Write:
0x004A TCTL3 Read: EDG7B EDG7A EDG6B EDG6A EDG5B EDG5A EDG4B EDG4A
Write:
0x004B TCTL4 Read: EDG3B EDG3A EDG2B EDG2A EDG1B EDG1A EDG0B EDG0A
Write:
0x004C TIE Read: C7I C6I C5I C4I C3I C2I C1I C0I
Write:
0x004D TSCR2 Read: TOI 000
TCRE PR2 PR1 PR0
Write:
0x004E TFLG1 Read: C7F C6F C5F C4F C3F C2F C1F C0F
Write:
0x004F TFLG2 Read: TOF 0000000
Write:
0x0050 TC0 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0051 TC0 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0052 TC1 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0053 TC1 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0054 TC2 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0055 TC2 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0056 TC3 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0057 TC3 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0058 TC4 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0059 TC4 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x005A TC5 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x005B TC5 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x005C TC6 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x005D TC6 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x005E TC7 (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 33
Rev 01.24
0x005F TC7 (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0060 PACTL Read: 0 PAEN PAMOD PEDGE CLK1 CLK0 PAOVI PAI
Write:
0x0061 PAFLG Read: 0 0 0 0 0 0 PAOVF PAIF
Write:
0x0062 PACNT (hi) Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
0x0063 PACNT (lo) Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x0064 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0065 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0066 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0067 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0068 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0069 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x006A Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x006B Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x006C Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x006D Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x006E Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x006F Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0070–0x007F Reserved
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0070–
0x007F Reserved Read: 0 0 0 0 0 0 0 0
Write:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
34 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x0080–0x009F ATD (Analog-to-Digital Converter 10 Bit 8 Channel)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0080 ATDCTL0 Read: 0 0 0 0 0 0 0 0
Write:
0x0081 ATDCTL1 Read: 0 0 0 0 0 0 0 0
Write:
0x0082 ATDCTL2 Read: ADPU AFFC AWAI ETRIGLE ETRIGP ETRIG ASCIE ASCIF
Write:
0x0083 ATDCTL3 Read: 0 S8C S4C S2C S1C FIFO FRZ1 FRZ0
Write:
0x0084 ATDCTL4 Read: SRES8 SMP1 SMP0 PRS4 PRS3 PRS2 PRS1 PRS0
Write:
0x0085 ATDCTL5 Read: DJM DSGN SCAN MULT 0CC CB CA
Write:
0x0086 ATDSTAT0 Read: SCF 0ETORF FIFOR 0 CC2 CC1 CC0
Write:
0x0087 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0088 ATDTEST0 Read: 0 0 0 0 0 0 0 0
Write:
0x0089 ATDTEST1 Read: 0 0 0 0 0 0 0 SC
Write:
0x008A Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x008B ATDSTAT1 Read: CCF7 CCF6 CCF5 CCF4 CCF3 CCF2 CCF1 CCF0
Write:
0x008C Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x008D ATDDIEN Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
0x008E Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x008F PORTAD Read: Bit7 6 5 4 3 2 1 BIT 0
Write:
0x0090 ATDDR0H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x0091 ATDDR0L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
0x0092 ATDDR1H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x0093 ATDDR1L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
0x0094 ATDDR2H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x0095 ATDDR2L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 35
Rev 01.24
0x0096 ATDDR3H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x0097 ATDDR3L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
0x0098 ATDDR4H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x0099 ATDDR4L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
0x009A ATDDR5H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x009B ATDDR5L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
0x009C ATDDR6H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x009D ATDDR6L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
0x009E ATDDR7H Read: Bit15 14 13 12 11 10 9 Bit8
Write:
0x009F ATDDR7L Read: Bit7 Bit6 0 0 0 0 0 0
Write:
0x00A0–0x00C7 Reserved
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x00A0–
0x00C7 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x00C8–0x00CF SCI (Asynchronous Serial Interface)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x00C8 SCIBDH Read: 0 0 0 SBR12 SBR11 SBR10 SBR9 SBR8
Write:
0x00C9 SCIBDL Read: SBR7 SBR6 SBR5 SBR4 SBR3 SBR2 SBR1 SBR0
Write:
0x00CA SCICR1 Read: LOOPS SCISWAI RSRC M WAKE ILT PE PT
Write:
0x00CB SCICR2 Read: TIE TCIE RIE ILIE TE RE RWU SBK
Write:
0x00CC SCISR1 Read: TDRE TC RDRF IDLE OR NF FE PF
Write:
0x0080–0x009F ATD (Analog-to-Digital Converter 10 Bit 8 Channel) (continued)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
36 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x00CD SCISR2 Read: 0 0 0 0 0 BRK13 TXDIR RAF
Write:
0x00CE SCIDRH Read: R8 T8 000000
Write:
0x00CF SCIDRL Read: R7 R6 R5 R4 R3 R2 R1 R0
Write: T7 T6 T5 T4 T3 T2 T1 T0
0x00D0–0x00D7 Reserved
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x00D0–
0x00D7 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x00D8–0x00DF SPI (Serial Peripheral Interface)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x00D8 SPICR1 Read: SPIE SPE SPTIE MSTR CPOL CPHA SSOE LSBFE
Write:
0x00D9 SPICR2 Read: 0 0 0 MODFEN BIDIROE 0SPISWAI SPC0
Write:
0x00DA SPIBR Read: 0 SPPR2 SPPR1 SPPR0 0SPR2 SPR1 SPR0
Write:
0x00DB SPISR Read: SPIF 0 SPTEF MODF 0 0 0 0
Write:
0x00DC Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x00DD SPIDR Read: Bit7 6 5 4 3 2 1 Bit0
Write:
0x00DE Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x00DF Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x00C8–0x00CF SCI (Asynchronous Serial Interface) (continued)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 37
Rev 01.24
0x00E0–0x00FF PWM (Pulse Width Modulator)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
$00E0 PWME Read: 0 0 PWME5 PWME4 PWME3 PWME2 PWME1 PWME0
Write:
$00E1 PWMPOL Read: 0 0 PPOL5 PPOL4 PPOL3 PPOL2 PPOL1 PPOL0
Write:
$00E2 PWMCLK Read: 0 0 PCLK5 PCLK4 PCLK3 PCLK2 PCLK1 PCLK0
Write:
$00E3 PWMPRCLK Read: 0 PCKB2 PCKB1 PCKB0 0PCKA2 PCKA1 PCKA0
Write:
$00E4 PWMCAE Read: 0 0 CAE5 CAE4 CAE3 CAE2 CAE1 CAE0
Write:
$00E5 PWMCTL Read: 0 CON45 CON23 CON01 PSWAI PFRZ 00
Write:
$00E6 PWMTST
Test Only
Read: 0 0 0 0 0 0 0 0
Write:
$00E7 PWMPRSC Read: 0 0 0 0 0 0 0 0
Write:
$00E8 PWMSCLA Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00E9 PWMSCLB Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00EA PWMSCNTA Read: 0 0 0 0 0 0 0 0
Write:
$00EB PWMSCNTB Read: 0 0 0 0 0 0 0 0
Write:
$00EC PWMCNT0 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write: 0 0 0 0 0 0 0 0
$00ED PWMCNT1 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write: 0 0 0 0 0 0 0 0
$00EE PWMCNT2 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write: 0 0 0 0 0 0 0 0
$00EF PWMCNT3 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write: 0 0 0 0 0 0 0 0
$00F0 PWMCNT4 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write: 0 0 0 0 0 0 0 0
$00F1 PWMCNT5 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write: 0 0 0 0 0 0 0 0
$00F2 PWMPER0 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00F3 PWMPER1 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00F4 PWMPER2 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00F5 PWMPER3 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
38 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
$00F6 PWMPER4 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00F7 PWMPER5 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00F8 PWMDTY0 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00F9 PWMDTY1 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00FA PWMDTY2 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00FB PWMDTY3 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00FC PWMDTY4 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00FD PWMDTY5 Read: Bit 7 6 5 4 3 2 1 Bit 0
Write:
$00FE Reserved Read: PWMIF PWMIE 0PWMLVL 0 PWM5IN PWM5INL PWM5ENA
Write: PWMRSTRT
$00FF Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0110–0x013F Reserved
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0110–
0x003F Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0140–0x017F CAN (Scalable Controller Area Network — MSCAN)(1)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0140 CANCTL0 Read: RXFRM RXACT CSWAI SYNCH TIME WUPE SLPRQ INITRQ
Write:
0x0141 CANCTL1 Read: CANE CLKSRC LOOPB LISTEN 0WUPM SLPAK INITAK
Write:
0x0142 CANBTR0 Read: SJW1 SJW0 BRP5 BRP4 BRP3 BRP2 BRP1 BRP0
Write:
0x0143 CANBTR1 Read: SAMP TSEG22 TSEG21 TSEG20 TSEG13 TSEG12 TSEG11 TSEG10
Write:
0x0144 CANRFLG Read: WUPIF CSCIF RSTAT1 RSTAT0 TSTAT1 TSTAT0 OVRIF RXF
Write:
0x0145 CANRIER Read: WUPIE CSCIE RSTATE1 RSTATE0 TSTATE1 TSTATE0 OVRIE RXFIE
Write:
0x00E0–0x00FF PWM (Pulse Width Modulator) (continued)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 39
Rev 01.24
0x0146 CANTFLG Read: 0 0 0 0 0 TXE2 TXE1 TXE0
Write:
0x0147 CANTIER Read: 0 0 0 0 0 TXEIE2 TXEIE1 TXEIE0
Write:
0x0148 CANTARQ Read: 0 0 0 0 0 ABTRQ2 ABTRQ1 ABTRQ0
Write:
0x0149 CANTAAK Read: 0 0 0 0 0 ABTAK2 ABTAK1 ABTAK0
Write:
0x014A CANTBSEL Read: 0 0 0 0 0 TX2 TX1 TX0
Write:
0x014B CANIDAC Read: 0 0 IDAM1 IDAM0 0 IDHIT2 IDHIT1 IDHIT0
Write:
0x014C Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x014D Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x014E CANRXERR Read: RXERR7 RXERR6 RXERR5 RXERR4 RXERR3 RXERR2 RXERR1 RXERR0
Write:
0x014F CANTXERR Read: TXERR7 TXERR6 TXERR5 TXERR4 TXERR3 TXERR2 TXERR1 TXERR0
Write:
0x0150–
0x0153
CANIDAR0 -
CANIDAR3
Read: AC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
Write:
0x0154–
0x0157
CANIDMR0 -
CANIDMR3
Read: AM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
Write:
0x0158–
0x015B
CANIDAR4 -
CANIDAR7
Read: AC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
Write:
0x015C–
0x015F
CANIDMR4 -
CANIDMR7
Read: AM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
Write:
0x0160–
0x016F CANRXFG Read: FOREGROUND RECEIVE BUFFER see Table 1-2
Write:
0x0170–
0x017F CANTXFG Read: FOREGROUND TRANSMIT BUFFER see Table 1-2
Write:
1. Not available on the MC9S12GC Family members. Those memory locations should not be accessed.
Table 1-2. Detailed MSCAN Foreground Receive and Transmit Buffer Layout
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0xXXX0
Extended ID Read: ID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21
Standard ID Read: ID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3
CANxRIDR0 Write:
0xXXX1
Extended ID Read: ID20 ID19 ID18 SRR=1 IDE=1 ID17 ID16 ID15
Standard ID Read: ID2 ID1 ID0 RTR IDE=0
CANxRIDR1 Write:
0x0140–0x017F CAN (Scalable Controller Area Network — MSCAN)(1) (continued)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
40 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0xXXX2
Extended ID Read: ID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7
Standard ID Read:
CANxRIDR2 Write:
0xXXX3
Extended ID Read: ID6 ID5 ID4 ID3 ID2 ID1 ID0 RTR
Standard ID Read:
CANxRIDR3 Write:
0xXXX4–
0xXXXB
CANxRDSR0–
CANxRDSR7
Read: DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
Write:
0xXXXC CANRxDLR Read: DLC3 DLC2 DLC1 DLC0
Write:
0xXXXD Reserved Read:
Write:
0xXXXE CANxRTSRH Read: TSR15 TSR14 TSR13 TSR12 TSR11 TSR10 TSR9 TSR8
Write:
0xXXXF CANxRTSRL Read: TSR7 TSR6 TSR5 TSR4 TSR3 TSR2 TSR1 TSR0
Write:
0xxx10
Extended ID Read: ID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21
CANxTIDR0 Write:
Standard ID Read: ID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3
Write:
0xxx11
Extended ID Read: ID20 ID19 ID18 SRR=1 IDE=1 ID17 ID16 ID15
CANxTIDR1 Write:
Standard ID Read: ID2 ID1 ID0 RTR IDE=0
Write:
0xxx12
Extended ID Read: ID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7
CANxTIDR2 Write:
Standard ID Read:
Write:
0xxx13
Extended ID Read: ID6 ID5 ID4 ID3 ID2 ID1 ID0 RTR
CANxTIDR3 Write:
Standard ID Read:
Write:
0xxx14–
0xxx1B
CANxTDSR0–
CANxTDSR7
Read: DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
Write:
0xxx1C CANxTDLR Read: DLC3 DLC2 DLC1 DLC0
Write:
0xxx1D CONxTTBPR Read: PRIO7 PRIO6 PRIO5 PRIO4 PRIO3 PRIO2 PRIO1 PRIO0
Write:
0xxx1E CANxTTSRH Read: TSR15 TSR14 TSR13 TSR12 TSR11 TSR10 TSR9 TSR8
Write:
0xxx1F CANxTTSRL Read: TSR7 TSR6 TSR5 TSR4 TSR3 TSR2 TSR1 TSR0
Write:
Table 1-2. Detailed MSCAN Foreground Receive and Transmit Buffer Layout (continued)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 41
Rev 01.24
0x0180–0x023F Reserved
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0180–
0x023F Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0240–0x027F PIM (Port Interface Module) (Sheet 1 of 3)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0240 PTT Read: PTT7 PTT6 PTT5 PTT4 PTT3 PTT2 PTT1 PTT0
Write:
0x0241 PTIT Read: PTIT7 PTIT6 PTIT5 PTIT4 PTIT3 PTIT2 PTIT1 PTIT0
Write:
0x0242 DDRT Read: DDRT7 DDRT7 DDRT5 DDRT4 DDRT3 DDRT2 DDRT1 DDRT0
Write:
0x0243 RDRT Read: RDRT7 RDRT6 RDRT5 RDRT4 RDRT3 RDRT2 RDRT1 RDRT0
Write:
0x0244 PERT Read: PERT7 PERT6 PERT5 PERT4 PERT3 PERT2 PERT1 PERT0
Write:
0x0245 PPST Read: PPST7 PPST6 PPST5 PPST4 PPST3 PPST2 PPST1 PPST0
Write:
0x0246 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0247 MODRR Read: 0 0 0 MODRR4 MODRR3 MODRR2 MODRR1 MODRR0
Write:
0x0248 PTS Read: 0 0 0 0 PTS3 PTS2 PTS1 PTS0
Write:
0x0249 PTIS Read: 0 0 0 0 PTIS3 PTIS2 PTIS1 PTIS0
Write:
0x024A DDRS Read: 0 0 0 0 DDRS3 DDRS2 DDRS1 DDRS0
Write:
0x024B RDRS Read: 0 0 0 0 RDRS3 RDRS2 RDRS1 RDRS0
Write:
0x024C PERS Read: 0 0 0 0 PERS3 PERS2 PERS1 PERS0
Write:
0x024D PPSS Read: 0 0 0 0 PPSS3 PPSS2 PPSS1 PPSS0
Write:
0x024E WOMS Read: 0 0 0 0 WOMS3 WOMS2 WOMS1 WOMS0
Write:
0x024F Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0250 PTM Read: 0 0 PTM5 PTM4 PTM3 PTM2 PTM1 PTM0
Write:
0x0251 PTIM Read: 0 0 PTIM5 PTIM4 PTIM3 PTIM2 PTIM1 PTIM0
Write:
0x0252 DDRM Read: 0 0 DDRM5 DDRM4 DDRM3 DDRM2 DDRM1 DDRM0
Write:
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
42 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x0253 RDRM Read: 0 0 RDRM5 RDRM4 RDRM3 RDRM2 RDRM1 RDRM0
Write:
0x0254 PERM Read: 0 0 PERM5 PERM4 PERM3 PERM2 PERM1 PERM0
Write:
0x0255 PPSM Read: 0 0 PPSM5 PPSM4 PPSM3 PPSM2 PPSM1 PPSM0
Write:
0x0256 WOMM Read: 0 0 WOMM5 WOMM4 WOMM3 WOMM2 WOMM1 WOMM0
Write:
0x0257 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0258 PTP Read: PTP7 PTP6 PTP5 PTP4 PTP3 PTP2 PTP1 PTP0
Write:
0x0259 PTIP Read: PTIP7 PTIP6 PTIP5 PTIP4 PTIP3 PTIP2 PTIP1 PTIP0
Write:
0x025A DDRP Read: DDRP7 DDRP7 DDRP5 DDRP4 DDRP3 DDRP2 DDRP1 DDRP0
Write:
0x025B RDRP Read: RDRP7 RDRP6 RDRP5 RDRP4 RDRP3 RDRP2 RDRP1 RDRP0
Write:
0x025C PERP Read: PERP7 PERP6 PERP5 PERP4 PERP3 PERP2 PERP1 PERP0
Write:
0x025D PPSP Read: PPSP7 PPSP6 PPSP5 PPSP4 PPSP3 PPSP2 PPSP1 PPSS0
Write:
0x025E PIEP Read: PIEP7 PIEP6 PIEP5 PIEP4 PIEP3 PIEP2 PIEP1 PIEP0
Write:
0x025F PIFP Read: PIFP7 PIFP6 PIFP5 PIFP4 PIFP3 PIFP2 PIFP1 PIFP0
Write:
0x0260 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0261 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0262 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0263 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0264 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0265 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0266 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0267 Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0268 PTJ Read: PTJ7 PTJ6 000000
Write:
0x0269 PTIJ Read: PTIJ7 PTIJ6 0 0 0 0 0 0
Write:
0x0240–0x027F PIM (Port Interface Module) (Sheet 2 of 3)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 43
Rev 01.24
0x026A DDRJ Read: DDRJ7 DDRJ7 000000
Write:
0x026B RDRJ Read: RDRJ7 RDRJ6 000000
Write:
0x026C PERJ Read: PERJ7 PERJ6 000000
Write:
0x026D PPSJ Read: PPSJ7 PPSJ6 000000
Write:
0x026E PIEJ Read: PIEJ7 PIEJ6 000000
Write:
0x026F PIFJ Read: PIFJ7 PIFJ6 000000
Write:
0x0270 PTAD Read: PTAD7 PTAD6 PTAD5 PTAD4 PTAD3 PTAD2 PTAD1 PTAD0
Write:
0x0271 PTIAD Read: PTIAD7 PTIAD6 PTIAD5 PTIAD4 PTIAD3 PTIAD2 PTIAD1 PTIJ7
Write:
0x0272 DDRAD Read: DDRAD7 DDRAD6 DDRAD5 DDRAD4 DDRAD3 DDRAD2 DDRAD1 DDRAD0
Write:
0x0273 RDRAD Read: RDRAD7 RDRAD6 RDRAD5 RDRAD4 RDRAD3 RDRAD2 RDRAD1 RDRAD0
Write:
0x0274 PERAD Read: PERAD7 PERAD6 PERAD5 PERAD4 PERAD3 PERAD2 PERAD1 PERAD0
Write:
0x0275 PPSAD Read: PPSAD7 PPSAD6 PPSAD5 PPSAD4 PPSAD3 PPSAD2 PPSAD1 PPSAD0
Write:
0x0276-
0x027F Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0280–0x03FF Reserved Space
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0x0280–
0x2FF Reserved Read: 0 0 0 0 0 0 0 0
Write:
0x0300
–0x03FF Unimplemented Read: 0 0 0 0 0 0 0 0
Write:
0x0240–0x027F PIM (Port Interface Module) (Sheet 3 of 3)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
44 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.2.3 Part ID Assignments
The part ID is located in two 8-bit registers PARTIDH and PARTIDL (addresses 0x001A and ox001B after
reset). The read-only value is a unique part ID for each revision of the chip. Table 1-3 shows the assigned
part ID numbers for production mask sets.
The device memory sizes are located in two 8-bit registers MEMSIZ0 and MEMSIZ1 (addresses 0x001C
and 0x001D after reset). Table 1-4 shows the read-only values of these registers. Refer to Module Mapping
and Control (MMC) Block Guide for further details.
Table 1-3. Assigned Part ID Numbers
Device Mask Set Number Part ID(1)
1. The coding is as follows:
Bit 15–12: Major family identifier
Bit 11–8: Minor family identifier
Bit 7–4: Major mask set revision number including FAB transfers
Bit 3–0: Minor — non full — mask set revision
MC9S12C32 1L45J $3300
MC9S12C32 2L45J $3302
MC9S12C32 1M34C $3311
MC9S12GC16 2L45J $3302
MC9S12GC32 2L45J $3302
MC9S12GC32 1M34C $3311
MC9S12C64,MC9S12C96,MC9S12C128 2L09S $3102
MC9S12GC64,MC9S12GC96,MC9S12GC128 2L09S $3102
MC9S12C64,MC9S12C96,MC9S12C128 0M66G $3103
MC9S12GC64,MC9S12GC96,MC9S12GC128 0M66G $3103
Table 1-4. Memory Size Registers
Device Register Name Value
MC9S12GC16 MEMSIZ0 $00
MEMSIZ1 $80
MC9S12C32, MC9S12GC32 MEMSIZ0 $00
MEMSIZ1 $80
MC9S12C64, MC9S12GC64 MEMSIZ0 $01
MEMSIZ1 $C0
MC9S12C96,MC9S12GC96 MEMSIZ0 $01
MEMSIZ1 $C0
MC9S12C128, MC9S12GC128 MEMSIZ0 $01
MEMSIZ1 $C0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 45
Rev 01.24
1.3 Signal Description
1.3.1 Device Pinouts
Figure 1-7. Pin Assignments in 80-Pin QFP
The MODRR register within the PIM allows for mapping of PWM channels to Port T in the absence of
Port P pins for the low pin count packages. For the 80QFP package option it is recommended not to use
MODRR since this is intended to support PWM channel availability in low pin count packages. Note that
when mapping PWM channels to Port T in an 80QFP option, the associated PWM channels are then
mapped to both Port P and Port T
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
MC9S12C-Family /
MC9S12GC-Family
VRH
VDDA
PAD07/AN07
PAD06/AN06
PAD05/AN05
PAD04/AN04
PAD03/AN03
PAD02/AN02
PAD01/AN01
PAD00/AN00
VSS2
VDD2
PA7/ADDR15/DATA1
5
PA6/ADDR14/DATA1
4
PA5/ADDR13/DATA1
3
PA4/ADDR12/DATA1
2
PA3/ADDR11/DATA11
PA2/ADDR10/DATA1
0
PA1/ADDR9/DATA9
PA0/ADDR8/DATA8
PP4/KWP4/PW4
PP5/KWP5/PW5
PP7/KWP7
VDDX
VSSX
PM0/RXCAN
PM1/TXCAN
PM2/MISO
PM3/SS
PM4/MOSI
PM5/SCK
PJ6/KWJ6
PJ7/KWJ7
PP6/KWP6/ROMCT
L
PS3
PS2
PS1/TXD
PS0/RXD
VSSA
VRL
PW3/KWP3/PP3
PW2/KWP2/PP2
PW1/KWP1/PP1
PW0/KWP0/PP0
PW0/IOC0/PT0
PW1/IOC1/PT1
PW2/IOC2/PT2
PW3/IOC3/PT3
VDD1
VSS1
PW4/IOC4/PT4
IOC5/PT5
IOC6/PT6
IOC7/PT7
MODC/TAGHI/BKGD
ADDR0/DATA0/PB0
ADDR1/DATA1/PB1
ADDR2/DATA2/PB2
ADDR3/DATA3/PB3
ADDR4/DATA4/PB4
ADDR5/DATA5/PB5
ADDR6/DATA6/PB6
ADDR7/DATA7/PB7
XCLKS/NOACC/PE7
MODB/IPIPE1/PE6
MODA/IPIPE0/PE5
ECLK/PE4
VSSR
VDDR
RESET
VDDPLL
XFC
VSSPLL
EXTAL
XTAL
VPP/TEST
LSTRB/TAGLO/PE3
R/W/PE2
IRQ/PE1
XIRQ/PE0
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
Signals shown in Bold are not available on the 52- or 48-pin package
Signals shown in Bold Italic are available in the 52-pin, but not the 48-pin package
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
46 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-8. Pin Assignments in 52-Pin LQFP
MC9S12C-Family /
MC9S12GC-Family
1
2
3
4
5
6
7
8
9
10
11
12
13
39
38
37
36
35
34
33
32
31
30
29
28
27
14
15
16
17
18
19
20
21
22
23
24
25
26
52
51
50
49
48
47
46
45
44
43
42
41
40
* Signals shown in Bold italic are not available on the 48-pin package
PP4/KWP4/PW4
PP5/KWP5/PW5
VDDX
VSSX
PM0/RXCAN
PM1/TXCAN
PM2/MISO
PM3/SS
PM4/MOSI
PM5/SCK
PS1/TXD
PS0/RXD
VSSA
VRH
VDDA
PAD07/AN07
PAD06/AN06
PAD05/AN05
PAD04/AN04
PAD03/AN03
PAD02/AN02
PAD01/AN01
PAD00/AN00
PA 2
PA 1
PA0
XCLKS/PE7
ECLK/PE4
VSSR
VDDR
RESET
VDDPLL
XFC
VSSPLL
EXTAL
XTAL
VPP/TEST
IRQ/PE1
XIRQ/PE0
PW3/KWP3/PP3
PW0/IOC0/PT0
PW1/IOC1/PT1
PW2/IOC2/PT2
PW3/IOC3/PT3
VDD1
VSS1
IOC4/PT4
IOC5/PT5
IOC6/PT6
IOC7/PT7
MODC/BKGD
PB4
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 47
Rev 01.24
Figure 1-9. Pin Assignments in 48-Pin LQFP
MC9S12C-Family /
MC9S12GC-Family
1
2
3
4
5
6
7
8
9
10
11
12
36
35
34
33
32
31
30
29
28
27
26
25
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
PP5/KWP5/PW5
VDDX
VSSX
PM0/RXCAN
PM1/TXCAN
PM2/MISO
PM3/SS
PM4/MOSI
PM5/SCK
PS1/TXD
PS0/RXD
VSSA
PW0/IOC0/PT0
PW1/IOC1/PT1
PW2/IOC2/PT2
PW3/IOC3/PT3
VDD1
VSS1
IOC4/PT4
IOC5/PT5
IOC6/PT6
IOC7/PT7
MODC/BKGD
PB4
XCLKS/PE7
ECLK/PE4
VSSR
VDDR
RESET
VDDPLL
XFC
VSSPLL
EXTAL
XTAL
VPP/TEST
IRQ/PE1
VRH
VDDA
PAD07/AN07
PAD06/AN06
PAD05/AN05
PAD04/AN04
PAD03/AN03
PAD02/AN02
PAD01/AN01
PAD00/AN00
PA0
XIRQ/PE0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
48 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.3.2 Signal Properties Summary
Table 1-5. Signal Properties
Pin Name
Function 1
Pin Name
Function 2
Pin Name
Function 3
Power
Domain
Internal Pull
Resistor
Description
CTRL Reset
State
EXTAL — — VDDPLL NA NA Oscillator pins
XTAL — — VDDPLL NA NA
RESET — — VDDX None None External reset pin
XFC — — VDDPLL NA NA PLL loop filter pin
TEST VPP — VSSX NA NA Test pin only
BKGD MODC TAGHI VDDX Up Up Background debug, mode pin, tag signal high
PE7 NOACC XCLKS VDDX PUCR Up Port E I/O pin, access, clock select
PE6 IPIPE1 MODB VDDX
While RESET
pin is low: Down
Port E I/O pin and pipe status
PE5 IPIPE0 MODA VDDX
While RESET
pin is low: Down
Port E I/O pin and pipe status
PE4 ECLK — VDDX PUCR Mode
Dep(1) Port E I/O pin, bus clock output
PE3 LSTRB TAGLO VDDX PUCR Mode
Dep1Port E I/O pin, low strobe, tag signal low
PE2 R/W—V
DDX PUCR Mode
Dep1Port E I/O pin, R/W in expanded modes
PE1 IRQ — VDDX PUCR Up Port E input, external interrupt pin
PE0 XIRQ — VDDX PUCR Up Port E input, non-maskable interrupt pin
PA[7:3] ADDR[15:1/
DATA[15:1] —V
DDX PUCR Disabled Port A I/O pin and multiplexed address/data
PA[2:1] ADDR[10:9/
DATA[10:9] —V
DDX PUCR Disabled Port A I/O pin and multiplexed address/data
PA[0] ADDR[8]/
DATA[8] —V
DDX PUCR Disabled Port A I/O pin and multiplexed address/data
PB[7:5] ADDR[7:5]/
DATA[7:5] —V
DDX PUCR Disabled Port B I/O pin and multiplexed address/data
PB[4] ADDR[4]/
DATA[4] —V
DDX PUCR Disabled Port B I/O pin and multiplexed address/data
PB[3:0] ADDR[3:0]/
DATA[3:0] —V
DDX PUCR Disabled Port B I/O pin and multiplexed address/data
PAD[7:0] AN[7:0] — VDDA
PERAD/P
PSAD Disabled Port AD I/O pins and ATD inputs
PP[7] KWP[7] — VDDX
PERP/
PPSP Disabled Port P I/O pins and keypad wake-up
PP[6] KWP[6] ROMCTL VDDX
PERP/
PPSP Disabled Port P I/O pins, keypad wake-up, and ROMON
enable.
PP[5] KWP[5] PW5 VDDX
PERP/
PPSP Disabled Port P I/O pin, keypad wake-up, PW5 output
PP[4:3] KWP[4:3] PW[4:3] VDDX
PERP/
PPSP Disabled Port P I/O pin, keypad wake-up, PWM output
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 49
Rev 01.24
1.3.3 Pin Initialization for 48- and 52-Pin LQFP Bond Out Versions
Not Bonded Pins:
If the port pins are not bonded out in the chosen package the user should initialize the registers to
be inputs with enabled pull resistance to avoid excess current consumption. This applies to the
following pins:
(48LQFP): Port A[7:1], Port B[7:5], Port B[3:0], PortE[6,5,3,2], Port P[7:6], PortP[4:0], Port
J[7:6], PortS[3:2]
(52LQFP): Port A[7:3], Port B[7:5], Port B[3:0], PortE[6,5,3,2], Port P[7:6], PortP[2:0], Port
J[7:6], PortS[3:2]
PP[2:0] KWP[2:0] PW[2:0] VDDX
PERP/
PPSP Disabled Port P I/O pins, keypad wake-up, PWM outputs
PJ[7:6] KWJ[7:6] — VDDX
PERJ/
PPSJ Disabled Port J I/O pins and keypad wake-up
PM5 SCK — VDDX
PERM/
PPSM Up Port M I/O pin and SPI SCK signal
PM4 MOSI — VDDX
PERM/
PPSM Up Port M I/O pin and SPI MOSI signal
PM3 SS — VDDX
PERM/
PPSM Up Port M I/O pin and SPI SS signal
PM2 MISO — VDDX
PERM/
PPSM Up Port M I/O pin and SPI MISO signal
PM1 TXCAN — VDDX
PERM/
PPSM Up Port M I/O pin and CAN transmit signal(2)
PM0 RXCAN — VDDX
PERM/
PPSM Up Port M I/O pin and CAN receive signal2
PS[3:2] — — VDDX
PERS/
PPSS Up Port S I/O pins
PS1 TXD — VDDX
PERS/
PPSS Up Port S I/O pin and SCI transmit signal
PS0 RXD — VDDX
PERS/
PPSS Up Port S I/O pin and SCI receive signal
PT[7:5] IOC[7:5] — VDDX
PERT/
PPST Disabled Port T I/O pins shared with timer (TIM)
PT[4:0] IOC[4:0] PW[4:0] VDDX
PERT/
PPST Disabled Port T I/O pins shared with timer and PWM
1. The Port E output buffer enable signal control at reset is determined by the PEAR register and is mode dependent. For
example, in special test mode RDWE = LSTRE = 1 which enables the PE[3:2] output buffers and disables the pull-ups. Refer
to S12_MEBI user guide for PEAR register details.
2. CAN functionality is not available on the MC9S12GC Family members.
Table 1-5. Signal Properties (continued)
Pin Name
Function 1
Pin Name
Function 2
Pin Name
Function 3
Power
Domain
Internal Pull
Resistor
Description
CTRL Reset
State
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
50 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.3.4 Detailed Signal Descriptions
1.3.4.1 EXTAL, XTAL — Oscillator Pins
EXTAL and XTAL are the crystal driver and external clock pins. On reset all the device clocks are derived
from the EXTAL input frequency. XTAL is the crystal output.
1.3.4.2 RESET — External Reset Pin
RESET is an active low bidirectional control signal that acts as an input to initialize the MCU to a known
start-up state. It also acts as an open-drain output to indicate that an internal failure has been detected in
either the clock monitor or COP watchdog circuit. External circuitry connected to the RESET pin should
not include a large capacitance that would interfere with the ability of this signal to rise to a valid logic one
within 32 ECLK cycles after the low drive is released. Upon detection of any reset, an internal circuit
drives the RESET pin low and a clocked reset sequence controls when the MCU can begin normal
processing.
1.3.4.3 TEST / VPP — Test Pin
This pin is reserved for test and must be tied to VSS in all applications.
1.3.4.4 XFC — PLL Loop Filter Pin
Dedicated pin used to create the PLL loop filter. See CRG BUG for more detailed information.PLL loop
filter. Please ask your Motorola representative for the interactive application note to compute PLL loop
filter elements. Any current leakage on this pin must be avoided.
Figure 1-10. PLL Loop Filter Connections
1.3.4.5 BKGD / TAGHI / MODC — Background Debug, Tag High, and Mode Pin
The BKGD / TAGHI / MODC pin is used as a pseudo-open-drain pin for the background debug
communication. In MCU expanded modes of operation when instruction tagging is on, an input low on
this pin during the falling edge of E-clock tags the high half of the instruction word being read into the
instruction queue. It is also used as a MCU operating mode select pin at the rising edge during reset, when
the state of this pin is latched to the MODC bit.
MCU
XFC
R0
CS
CP
VDDPLL
VDDPLL
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 51
Rev 01.24
1.3.4.6 PA[7:0] / ADDR[15:8] / DATA[15:8] — Port A I/O Pins
PA7–PA0 are general purpose input or output pins,. In MCU expanded modes of operation, these pins are
used for the multiplexed external address and data bus. PA[7:1] pins are not available in the 48-pin package
version. PA[7:3] are not available in the 52-pin package version.
1.3.4.7 PB[7:0] / ADDR[7:0] / DATA[7:0] — Port B I/O Pins
PB7–PB0 are general purpose input or output pins. In MCU expanded modes of operation, these pins are
used for the multiplexed external address and data bus. PB[7:5] and PB[3:0] pins are not available in the
48-pin nor 52-pin package version.
1.3.4.8 PE7 / NOACC / XCLKS — Port E I/O Pin 7
PE7 is a general purpose input or output pin. During MCU expanded modes of operation, the NOACC
signal, when enabled, is used to indicate that the current bus cycle is an unused or “free” cycle. This signal
will assert when the CPU is not using the bus.The XCLKS is an input signal which controls whether a
crystal in combination with the internal Colpitts (low power) oscillator is used or whether Pierce
oscillator/external clock circuitry is used. The state of this pin is latched at the rising edge of RESET. If
the input is a logic low the EXTAL pin is configured for an external clock drive or a Pierce oscillator. If
input is a logic high a Colpitts oscillator circuit is configured on EXTAL and XTAL. Since this pin is an
input with a pull-up device during reset, if the pin is left floating, the default configuration is a Colpitts
oscillator circuit on EXTAL and XTAL.
Figure 1-11. Colpitts Oscillator Connections (PE7 = 1)
Figure 1-12. Pierce Oscillator Connections (PE7 = 0)
MCU
C2
EXTAL
XTAL
Crystal or
VSSPLL
Ceramic Resonator
C
1
CDC1
1. Due to the nature of a translated ground Colpitts oscillator a DC voltage
bias is applied to the crystal. Please contact the crystal manufacturer for
crystal DC.
MCU
EXTAL
XTAL
RS1
RB
VSSPLL
Crystal or
Ceramic Resonator
C2
C1
1. RS can be zero (shorted) when used with higher frequency crystals,
refer to manufacturer’s data.
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
52 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-13. External Clock Connections (PE7 = 0)
1.3.4.9 PE6 / MODB / IPIPE1 — Port E I/O Pin 6
PE6 is a general purpose input or output pin. It is used as a MCU operating mode select pin during reset.
The state of this pin is latched to the MODB bit at the rising edge of RESET. This pin is shared with the
instruction queue tracking signal IPIPE1. This pin is an input with a pull-down device which is only active
when RESET is low. PE[6] is not available in the 48- / 52-pin package versions.
1.3.4.10 PE5 / MODA / IPIPE0 — Port E I/O Pin 5
PE5 is a general purpose input or output pin. It is used as a MCU operating mode select pin during reset.
The state of this pin is latched to the MODA bit at the rising edge of RESET. This pin is shared with the
instruction queue tracking signal IPIPE0. This pin is an input with a pull-down device which is only active
when RESET is low. This pin is not available in the 48- / 52-pin package versions.
1.3.4.11 PE4 / ECLK— Port E I/O Pin [4] / E-Clock Output
ECLK is the output connection for the internal bus clock. It is used to demultiplex the address and data in
expanded modes and is used as a timing reference. ECLK frequency is equal to 1/2 the crystal frequency
out of reset. The ECLK pin is initially configured as ECLK output with stretch in all expanded modes. The
E clock output function depends upon the settings of the NECLK bit in the PEAR register, the IVIS bit in
the MODE register and the ESTR bit in the EBICTL register. All clocks, including the E clock, are halted
when the MCU is in stop mode. It is possible to configure the MCU to interface to slow external memory.
ECLK can be stretched for such accesses. Reference the MISC register (EXSTR[1:0] bits) for more
information. In normal expanded narrow mode, the E clock is available for use in external select decode
logic or as a constant speed clock for use in the external application system. Alternatively PE4 can be used
as a general purpose input or output pin.
1.3.4.12 PE3 / LSTRB — Port E I/O Pin [3] / Low-Byte Strobe (LSTRB)
In all modes this pin can be used as a general-purpose I/O and is an input with an active pull-up out of
reset. If the strobe function is required, it should be enabled by setting the LSTRE bit in the PEAR register.
This signal is used in write operations. Therefore external low byte writes will not be possible until this
function is enabled. This pin is also used as TAGLO in special expanded modes and is multiplexed with
the LSTRB function. This pin is not available in the 48- / 52-pin package versions.
MCU
EXTAL
XTAL Not Connected
CMOS Compatible
External Oscillator
(VDDPLL Level)
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 53
Rev 01.24
1.3.4.13 PE2 / R/W — Port E I/O Pin [2] / Read/Write
In all modes this pin can be used as a general-purpose I/O and is an input with an active pull-up out of
reset. If the read/write function is required it should be enabled by setting the RDWE bit in the PEAR
register. External writes will not be possible until enabled. This pin is not available in the 48- / 52-pin
package versions.
1.3.4.14 PE1 / IRQ — Port E Input Pin [1] / Maskable Interrupt Pin
The IRQ input provides a means of applying asynchronous interrupt requests to the MCU. Either falling
edge-sensitive triggering or level-sensitive triggering is program selectable (INTCR register). IRQ is
always enabled and configured to level-sensitive triggering out of reset. It can be disabled by clearing
IRQEN bit (INTCR register). When the MCU is reset the IRQ function is masked in the condition code
register. This pin is always an input and can always be read. There is an active pull-up on this pin while in
reset and immediately out of reset. The pull-up can be turned off by clearing PUPEE in the PUCR register.
1.3.4.15 PE0 / XIRQ — Port E input Pin [0] / Non Maskable Interrupt Pin
The XIRQ input provides a means of requesting a non-maskable interrupt after reset initialization. During
reset, the X bit in the condition code register (CCR) is set and any interrupt is masked until MCU software
enables it. Because the XIRQ input is level sensitive, it can be connected to a multiple-source wired-OR
network. This pin is always an input and can always be read. There is an active pull-up on this pin while
in reset and immediately out of reset. The pull-up can be turned off by clearing PUPEE in the PUCR
register.
1.3.4.16 PAD[7:0] / AN[7:0] — Port AD I/O Pins [7:0]
PAD7–PAD0 are general purpose I/O pins and also analog inputs for the analog to digital converter. In
order to use a PAD pin as a standard input, the corresponding ATDDIEN register bit must be set. These
bits are cleared out of reset to configure the PAD pins for A/D operation.
When the A/D converter is active in multi-channel mode, port inputs are scanned and converted
irrespective of Port AD configuration. Thus Port AD pins that are configured as digital inputs or digital
outputs are also converted in the A/D conversion sequence.
1.3.4.17 PP[7] / KWP[7] — Port P I/O Pin [7]
PP7 is a general purpose input or output pin, shared with the keypad interrupt function. When configured
as an input, it can generate interrupts causing the MCU to exit stop or wait mode. This pin is not available
in the 48- / 52-pin package versions.
1.3.4.18 PP[6] / KWP[6]/ROMCTL — Port P I/O Pin [6]
PP6 is a general purpose input or output pin, shared with the keypad interrupt function. When configured
as an input, it can generate interrupts causing the MCU to exit stop or wait mode. This pin is not available
in the 48- / 52-pin package versions. During MCU expanded modes of operation, this pin is used to enable
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
54 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
the Flash EEPROM memory in the memory map (ROMCTL). At the rising edge of RESET, the state of
this pin is latched to the ROMON bit.
• PP6 = 1 in emulation modes equates to ROMON = 0 (ROM space externally mapped)
• PP6 = 0 in expanded modes equates to ROMON = 0 (ROM space externally mapped)
1.3.4.19 PP[5:0] / KWP[5:0] / PW[5:0] — Port P I/O Pins [5:0]
PP[5:0] are general purpose input or output pins, shared with the keypad interrupt function. When
configured as inputs, they can generate interrupts causing the MCU to exit stop or wait mode.
PP[5:0] are also shared with the PWM output signals, PW[5:0]. Pins PP[2:0] are only available in the 80-
pin package version. Pins PP[4:3] are not available in the 48-pin package version.
1.3.4.20 PJ[7:6] / KWJ[7:6] — Port J I/O Pins [7:6]
PJ[7:6] are general purpose input or output pins, shared with the keypad interrupt function. When
configured as inputs, they can generate interrupts causing the MCU to exit stop or wait mode. These pins
are not available in the 48-pin package version nor in the 52-pin package version.
1.3.4.21 PM5 / SCK — Port M I/O Pin 5
PM5 is a general purpose input or output pin and also the serial clock pin SCK for the serial peripheral
interface (SPI).
1.3.4.22 PM4 / MOSI — Port M I/O Pin 4
PM4 is a general purpose input or output pin and also the master output (during master mode) or slave
input (during slave mode) pin for the serial peripheral interface (SPI).
1.3.4.23 PM3 / SS — Port M I/O Pin 3
PM3 is a general purpose input or output pin and also the slave select pin SS for the serial peripheral
interface (SPI).
1.3.4.24 PM2 / MISO — Port M I/O Pin 2
PM2 is a general purpose input or output pin and also the master input (during master mode) or slave
output (during slave mode) pin for the serial peripheral interface (SPI).
1.3.4.25 PM1 / TXCAN — Port M I/O Pin 1
PM1 is a general purpose input or output pin and the transmit pin, TXCAN, of the CAN module if
available.
1.3.4.26 PM0 / RXCAN — Port M I/O Pin 0
PM0 is a general purpose input or output pin and the receive pin, RXCAN, of the CAN module if available.
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 55
Rev 01.24
1.3.4.27 PS[3:2] — Port S I/O Pins [3:2]
PS3 and PS2 are general purpose input or output pins. These pins are not available in the 48- / 52-pin
package versions.
1.3.4.28 PS1 / TXD — Port S I/O Pin 1
PS1 is a general purpose input or output pin and the transmit pin, TXD, of serial communication interface
(SCI).
1.3.4.29 PS0 / RXD — Port S I/O Pin 0
PS0 is a general purpose input or output pin and the receive pin, RXD, of serial communication interface
(SCI).
1.3.4.30 PT[7:5] / IOC[7:5] — Port T I/O Pins [7:5]
PT7–PT5 are general purpose input or output pins. They can also be configured as the timer system input
capture or output compare pins IOC7-IOC5.
1.3.4.31 PT[4:0] / IOC[4:0] / PW[4:0]— Port T I/O Pins [4:0]
PT4–PT0 are general purpose input or output pins. They can also be configured as the timer system input
capture or output compare pins IOC[n] or as the PWM outputs PW[n].
1.3.5 Power Supply Pins
1.3.5.1 VDDX,VSSX — Power and Ground Pins for I/O Drivers
External power and ground for I/O drivers. Bypass requirements depend on how heavily the MCU pins are
loaded.
1.3.5.2 VDDR, VSSR — Power and Ground Pins for I/O Drivers and for Internal
Voltage Regulator
External power and ground for the internal voltage regulator. Connecting VDDR to ground disables the
internal voltage regulator.
1.3.5.3 VDD1, VDD2, VSS1, VSS2 — Internal Logic Power Pins
Power is supplied to the MCU through VDD and VSS. This 2.5V supply is derived from the internal voltage
regulator. There is no static load on those pins allowed. The internal voltage regulator is turned off, if VDDR
is tied to ground.
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
56 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.3.5.4 VDDA, VSSA — Power Supply Pins for ATD and VREG
VDDA,V
SSA are the power supply and ground input pins for the voltage regulator reference and the analog
to digital converter.
1.3.5.5 VRH, VRL — ATD Reference Voltage Input Pins
VRH and VRL are the reference voltage input pins for the analog to digital converter.
1.3.5.6 VDDPLL, VSSPLL — Power Supply Pins for PLL
Provides operating voltage and ground for the oscillator and the phased-locked loop. This allows the
supply voltage to the oscillator and PLL to be bypassed independently. This 2.5V voltage is generated by
the internal voltage regulator.
NOTE
All VSS pins must be connected together in the application. Because fast
signal transitions place high, short-duration current demands on the power
supply, use bypass capacitors with high-frequency characteristics and place
them as close to the MCU as possible. Bypass requirements depend on
MCU pin load.
Table 1-6. Power and Ground Connection Summary
Mnemonic Nominal
Voltage (V) Description
VDD1, VDD2 2.5 Internal power and ground generated by internal regulator. These also allow an external source
to supply the core VDD/VSS voltages and bypass the internal voltage regulator.
In the 48 and 52 LQFP packages VDD2 and VSS2 are not available.
VSS1, VSS2 0
VDDR 5.0 External power and ground, supply to internal voltage regulator.
VSSR 0
VDDX 5.0 External power and ground, supply to pin drivers.
VSSX 0
VDDA 5.0 Operating voltage and ground for the analog-to-digital converters and the reference for the
internal voltage regulator, allows the supply voltage to the A/D to be bypassed independently.
VSSA 0
VRH 5.0 Reference voltage low for the ATD converter.
In the 48 and 52 LQFP packages VRL is bonded to VSSA.
VRL 0
VDDPLL 2.5 Provides operating voltage and ground for the phased-locked loop. This allows the supply voltage
to the PLL to be bypassed independently. Internal power and ground generated by internal
regulator.
VSSPLL 0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 57
Rev 01.24
1.4 System Clock Description
The clock and reset generator provides the internal clock signals for the core and all peripheral modules.
Figure 1-14 shows the clock connections from the CRG to all modules. Consult the CRG Block User
Guide for details on clock generation.
Figure 1-14. Clock Connections
1.5 Modes of Operation
Eight possible modes determine the device operating configuration. Each mode has an associated default
memory map and external bus configuration controlled by a further pin.
Three low power modes exist for the device.
1.5.1 Chip Configuration Summary
The operating mode out of reset is determined by the states of the MODC, MODB, and MODA pins during
reset. The MODC, MODB, and MODA bits in the MODE register show the current operating mode and
provide limited mode switching during operation. The states of the MODC, MODB, and MODA pins are
latched into these bits on the rising edge of the reset signal. The ROMCTL signal allows the setting of the
ROMON bit in the MISC register thus controlling whether the internal Flash is visible in the memory map.
ROMON = 1 mean the Flash is visible in the memory map. The state of the ROMCTL pin is latched into
the ROMON bit in the MISC register on the rising edge of the reset signal.
CRG Bus Clock
Core Clock
EXTAL
XTAL
Oscillator Clock
S12_CORE
VREG
RAM
SCI
ATD
Flash
TIM
TPM
SPI
MSCAN
PIM
Not on 9S12GC
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
58 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
For further explanation on the modes refer to the S12_MEBI block guide.
1.5.2 Security
The device will make available a security feature preventing the unauthorized read and write of the
memory contents. This feature allows:
• Protection of the contents of FLASH,
• Operation in single-chip mode,
• Operation from external memory with internal FLASH disabled.
The user must be reminded that part of the security must lie with the user’s code. An extreme example
would be user’s code that dumps the contents of the internal program. This code would defeat the purpose
of security. At the same time the user may also wish to put a back door in the user’s program. An example
of this is the user downloads a key through the SCI which allows access to a programming routine that
updates parameters.
1.5.2.1 Securing the Microcontroller
Once the user has programmed the FLASH, the part can be secured by programming the security bits
located in the FLASH module. These non-volatile bits will keep the part secured through resetting the part
and through powering down the part.
Table 1-7. Mode Selection
BKGD =
MODC
PE6 =
MODB
PE5 =
MODA
PP6 =
ROMCTL
ROMON
Bit Mode Description
000 X 1
Special Single Chip, BDM allowed and ACTIVE. BDM is allowed in
all other modes but a serial command is required to make BDM
active.
001 0 1 Emulation Expanded Narrow, BDM allowed
10
0 1 0 X 0 Special Test (Expanded Wide), BDM allowed
011 0 1 Emulation Expanded Wide, BDM allowed
10
1 0 0 X 1 Normal Single Chip, BDM allowed
101 0 0 Normal Expanded Narrow, BDM allowed
11
110 X 1
Peripheral; BDM allowed but bus operations would cause bus
conflicts (must not be used)
111 0 0 Normal Expanded Wide, BDM allowed
11
Table 1-8. Clock Selection Based on PE7
PE7 = XCLKS Description
1 Colpitts Oscillator selected
0 Pierce Oscillator/external clock selected
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 59
Rev 01.24
The security byte resides in a portion of the Flash array.
Check the Flash Block User Guide for more details on the security configuration.
1.5.2.2 Operation of the Secured Microcontroller
1.5.2.2.1 Normal Single Chip Mode
This will be the most common usage of the secured part. Everything will appear the same as if the part was
not secured with the exception of BDM operation. The BDM operation will be blocked.
1.5.2.2.2 Executing from External Memory
The user may wish to execute from external space with a secured microcontroller. This is accomplished
by resetting directly into expanded mode. The internal FLASH will be disabled. BDM operations will be
blocked.
1.5.2.3 Unsecuring the Microcontroller
In order to unsecure the microcontroller, the internal FLASH must be erased. This can be done through an
external program in expanded mode or via a sequence of BDM commands. Unsecuring is also possible via
the Backdoor Key Access. Refer to Flash Block Guide for details.
Once the user has erased the FLASH, the part can be reset into special single chip mode. This invokes a
program that verifies the erasure of the internal FLASH. Once this program completes, the user can erase
and program the FLASH security bits to the unsecured state. This is generally done through the BDM, but
the user could also change to expanded mode (by writing the mode bits through the BDM) and jumping to
an external program (again through BDM commands). Note that if the part goes through a reset before the
security bits are reprogrammed to the unsecure state, the part will be secured again.
1.5.3 Low-Power Modes
The microcontroller features three main low power modes. Consult the respective Block User Guide for
information on the module behavior in stop, pseudo stop, and wait mode. An important source of
information about the clock system is the Clock and Reset Generator User Guide (CRG).
1.5.3.1 Stop
Executing the CPU STOP instruction stops all clocks and the oscillator thus putting the chip in fully static
mode. Wake up from this mode can be done via reset or external interrupts.
1.5.3.2 Pseudo Stop
This mode is entered by executing the CPU STOP instruction. In this mode the oscillator is still running
and the real time interrupt (RTI) or watchdog (COP) sub module can stay active. Other peripherals are
turned off. This mode consumes more current than the full stop mode, but the wake up time from this mode
is significantly shorter.
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
60 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.5.3.3 Wait
This mode is entered by executing the CPU WAI instruction. In this mode the CPU will not execute
instructions. The internal CPU signals (address and data bus) will be fully static. All peripherals stay
active. For further power consumption reduction the peripherals can individually turn off their local clocks.
1.5.3.4 Run
Although this is not a low-power mode, unused peripheral modules should not be enabled in order to save
power.
1.6 Resets and Interrupts
Consult the Exception Processing section of the CPU12 Reference Manual for information.
1.6.1 Vectors
Table 1-9 lists interrupt sources and vectors in default order of priority.
Table 1-9. Interrupt Vector Locations
Vector Address Interrupt Source CCR
Mask Local Enable HPRIO Value
to Elevate
0xFFFE, 0xFFFF
External reset, power on reset,
or low voltage reset
(see CRG flags register to determine
reset source)
None None —
0xFFFC, 0xFFFD Clock monitor fail reset None COPCTL (CME, FCME) —
0xFFFA, 0xFFFB COP failure reset None COP rate select —
0xFFF8, 0xFFF9 Unimplemented instruction trap None None —
0xFFF6, 0xFFF7 SWI None None —
0xFFF4, 0xFFF5 XIRQ X-Bit None —
0xFFF2, 0xFFF3 IRQ I bit INTCR (IRQEN) 0x00F2
0xFFF0, 0xFFF1 Real time Interrupt I bit CRGINT (RTIE) 0x00F0
0xFFEE, 0xFFEF Standard timer channel 0 I bit TIE (C0I) 0x00EE
0xFFEC, 0xFFED Standard timer channel 1 I bit TIE (C1I) 0x00EC
$FFEE, $FFEF Reserved
$FFEC, $FFED Reserved
0xFFEA, 0xFFEB Standard timer channel 2 I bit TIE (C2I) 0x00EA
0xFFE8, 0xFFE9 Standard timer channel 3 I bit TIE (C3I) 0x00E8
0xFFE6, 0xFFE7 Standard timer channel 4 I bit TIE (C4I) 0x00E6
0xFFE4, 0xFFE5 Standard timer channel 5 I bit TIE (C5I) 0x00E4
0xFFE2, 0xFFE3 Standard timer channel 6 I bit TIE (C6I) 0x00E2
0xFFE0, 0xFFE1 Standard timer channel 7 I bit TIE (C7I) 0x00E0
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 61
Rev 01.24
0xFFDE, 0xFFDF Standard timer overflow I bit TMSK2 (TOI) 0x00DE
0xFFDC, 0xFFDD Pulse accumulator A overflow I bit PACTL (PAOVI) 0x00DC
0xFFDA, 0xFFDB Pulse accumulator input edge I bit PACTL (PAI) 0x00DA
0xFFD8, 0xFFD9 SPI I bit SPICR1 (SPIE, SPTIE) 0x00D8
0xFFD6, 0xFFD7 SCI I bit SCICR2
(TIE, TCIE, RIE, ILIE) 0x00D6
0xFFD4, 0xFFD5 Reserved
0xFFD2, 0xFFD3 ATD I bit ATDCTL2 (ASCIE) 0x00D2
0xFFD0, 0xFFD1 Reserved
0xFFCE, 0xFFCF Port J I bit PIEP (PIEP7-6) 0x00CE
0xFFCC, 0xFFCD Reserved
0xFFCA, 0xFFCB Reserved
0xFFC8, 0xFFC9 Reserved
0xFFC6, 0xFFC7 CRG PLL lock I bit PLLCR (LOCKIE) 0x00C6
0xFFC4, 0xFFC5 CRG self clock mode I bit PLLCR (SCMIE) 0x00C4
0xFFBA to 0xFFC3 Reserved
0xFFB8, 0xFFB9 FLASH I bit FCNFG (CCIE, CBEIE) 0x00B8
0xFFB6, 0xFFB7 CAN wake-up(1) I bit CANRIER (WUPIE) 0x00B6
0xFFB4, 0xFFB5 CAN errors1I bit CANRIER (CSCIE, OVRIE) 0x00B4
0xFFB2, 0xFFB3 CAN receive1I bit CANRIER (RXFIE) 0x00B2
0xFFB0, 0xFFB1 CAN transmit1I bit CANTIER (TXEIE[2:0]) 0x00B0
0xFF90 to 0xFFAF Reserved
0xFF8E, 0xFF8F Port P I bit PIEP (PIEP7-0) 0x008E
0xFF8C, 0xFF8D Reserved
0xFF8C, 0xFF8D PWM Emergency Shutdown I bit PWMSDN(PWMIE) 0x008C
0xFF8A, 0xFF8B VREG LVI I bit CTRL0 (LVIE) 0x008A
0xFF80 to 0xFF89 Reserved
1. Not available on MC9S12GC Family members
Table 1-9. Interrupt Vector Locations (continued)
Vector Address Interrupt Source CCR
Mask Local Enable HPRIO Value
to Elevate
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
62 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.6.2 Resets
Resets are a subset of the interrupts featured in Table 1-9. The different sources capable of generating a
system reset are summarized in Table 1-10. When a reset occurs, MCU registers and control bits are
changed to known start-up states. Refer to the respective module Block User Guides for register reset
states.
1.6.2.1 Reset Summary Table
1.6.2.2 Effects of Reset
When a reset occurs, MCU registers and control bits are changed to known start-up states. Refer to the
respective module Block User Guides for register reset states. Refer to the HCS12 Multiplexed External
Bus Interface (MEBI) Block Guide for mode dependent pin configuration of port A, B and E out of reset.
Refer to the PIM Block User Guide for reset configurations of all peripheral module ports.
Refer to Figure 1-2 to Figure 1-6 footnotes for locations of the memories depending on the operating mode
after reset.
The RAM array is not automatically initialized out of reset.
NOTE
For devices assembled in 48-pin or 52-pin LQFP packages all non-bonded
out pins should be configured as outputs after reset in order to avoid current
drawn from floating inputs. Refer to Table 1-5 for affected pins.
1.7 Device Specific Information and Module Dependencies
1.7.1 PPAGE
External paging is not supported on these devices. In order to access the 16K flash blocks in the address
range 0x8000–0xBFFF the PPAGE register must be loaded with the corresponding value for this range.
Refer to Table 1-11 for device specific page mapping.
For all devices Flash Page 3F is visible in the 0xC000–0xFFFF range if ROMON is set. For all devices
(except MC9S12GC16) Page 3E is also visible in the 0x4000–0x7FFF range if ROMHM is cleared and
ROMON is set. For all devices apart from MC9S12C32 Flash Page 3D is visible in the 0x0000–0x3FFF
range if ROMON is set...
Table 1-10. Reset Summary
Reset Priority Source Vector
Power-on Reset 1 CRG module 0xFFFE, 0xFFFF
External Reset 1 RESET pin 0xFFFE, 0xFFFF
Low Voltage Reset 1 VREG module 0xFFFE, 0xFFFF
Clock Monitor Reset 2 CRG module 0xFFFC, 0xFFFD
COP Watchdog Reset 3 CRG module 0xFFFA, 0xFFFB
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 63
Rev 01.24
1.7.2 BDM Alternate Clock
The BDM section reference to alternate clock is equivalent to the oscillator clock.
1.7.3 Extended Address Range Emulation Implications
In order to emulate the MC9S12GC or MC9S12C-Family / MC9S12GC-Family devices, external
addressing of a 128K memory map is required. This is provided in a 112 LQFP package version which
includes the 3 necessary extra external address bus signals via PortK[2:0]. This package version is for
emulation only and not provided as a general production package.
The reset state of DDRK is 0x0000, configuring the pins as inputs.
The reset state of PUPKE in the PUCR register is “1” enabling the internal Port K pullups.
In this reset state the pull-ups provide a defined state and prevent a floating input, thereby preventing
unnecessary current flow at the input stage.
To prevent unnecessary current flow in production package options, the states of DDRK and PUPKE
should not be changed by software.
Table 1-11. Device Specific Flash PAGE Mapping
Device PAGE PAGE Visible with PPAGE Contents
MC9S12GC16 3F $01,$03,$05,$07,$09......$35,$37,$39,$3B,$3D,$3F
MC9S12C32
MC9S12GC32
3E $00,$02,$04,$06,$08,$0A,$0C,$0E,$10,$12......$2C,$2E,$30,$32,$34,$36,$38,$3A,$3C,$3E
3F $01,$03,$05,$07,$09,$0B,$0D,$0F,$11,$13.....$2D,$2F,$31,$33,$35,$37,$39,$3B,$3D,$3F
MC9S12C64
MC9S12GC64
3C $04,$0C,$14,$1C,$24,$2C,$34,$3C
3D $05,$0D,$15,$1D,$25,$2D,$35,$3D
3E $06,$0E,$16,$1E,$26,$2E,$36,$3E
3F $07,$0F,$17,$1F,$27,$2F,$37,$3F
MC9S12C96
MC9S12GC96
3A $02,$0A,$12,$1A,$22,$2A,$32,$3A
3B $03,$0B,$13,$1B,$23,$2B,$33,$3B
3C $04,$0C,$14,$1C,$24,$2C,$34,$3C
3D $05,$0D,$15,$1D,$25,$2D,$35,$3D
3E $06,$0E,$16,$1E,$26,$2E,$36,$3E
3F $07,$0F,$17,$1F,$27,$2F,$37,$3F
MC9S12C128
MC9S12GC128
38 $00,$08,$10,$18,$20,$28,$30,$38
39 $01,$09,$11,$19,$21,$29,$31,$39
3A $02,$0A,$12,$1A,$22,$2A,$32,$3A
3B $03,$0B,$13,$1B,$23,$2B,$33,$3B
3C $04,$0C,$14,$1C,$24,$2C,$34,$3C
3D $05,$0D,$15,$1D,$25,$2D,$35,$3D
3E $06,$0E,$16,$1E,$26,$2E,$36,$3E
3F $07,$0F,$17,$1F,$27,$2F,$37,$3F
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
64 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1.7.4 VREGEN
The VREGEN input mentioned in the VREG section is device internal, connected internally to VDDR.
1.7.5 VDD1, VDD2, VSS1, VSS2
In the 80-pin QFP package versions, both internal VDD and VSS of the 2.5V domain are bonded out on 2
sides of the device as two pin pairs (VDD1,V
SS1 &V
DD2,V
SS2). VDD1 and VDD2 are connected together
internally. VSS1 and VSS2 are connected together internally. The extra pin pair enables systems using the
80-pin package to employ better supply routing and further decoupling.
1.7.6 Clock Reset Generator And VREG Interface
The low voltage reset feature uses the low voltage reset signal from the VREG module as an input to the
CRG module. When the regulator output voltage supply to the internal chip logic falls below a specified
threshold the LVR signal from the VREG module causes the CRG module to generate a reset.
NOTE
If the voltage regulator is shut down by connecting VDDR to ground then the
LVRF flag in the CRG flags register (CRGFLG) is undefined.
1.7.7 Analog-to-Digital Converter
In the 48- and 52-pin package versions, the VRL pad is bonded internally to the VSSA pin.
1.7.8 MODRR Register Port T And Port P Mapping
The MODRR register within the PIM allows for mapping of PWM channels to port T in the absence of
port P pins for the low pin count packages. For the 80QFP package option it is recommended not to use
MODRR since this is intended to support PWM channel availability in low pin count packages. Note that
when mapping PWM channels to port T in an 80QFP option, the associated PWM channels are then
mapped to both port P and port T. .
1.7.9 Port AD Dependency On PIM And ATD Registers
The port AD pins interface to the PIM module. However, the port pin digital state can be read from either
the PORTAD register in the ATD register map or from the PTAD register in the PIM register map.
In order to read a digital pin value from PORTAD the corresponding ATDDIEN bit must be set and the
corresponding DDRDA bit cleared. If the corresponding ATDDIEN bit is cleared then the pin is configured
as an analog input and the PORTAD bit reads back as "1".
In order to read a digital pin value from PTAD, the corresponding DDRAD bit must be cleared, to
configure the pin as an input.
Furthermore in order to use a port AD pin as an analog input, the corresponding DDRAD bit must be
cleared to configure the pin as an input
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 65
Rev 01.24
1.8 Recommended Printed Circuit Board Layout
The PCB must be carefully laid out to ensure proper operation of the voltage regulator as well as of the
MCU itself. The following rules must be observed:
• Every supply pair must be decoupled by a ceramic capacitor connected as near as possible to the
corresponding pins.
• Central point of the ground star should be the VSSR pin.
• Use low ohmic low inductance connections between VSS1, VSS2, and VSSR.
•V
SSPLL must be directly connected to VSSR.
• Keep traces of VSSPLL, EXTAL, and XTAL as short as possible and occupied board area for C6,
C7, C11, and Q1 as small as possible.
• Do not place other signals or supplies underneath area occupied by C6, C7, C5, and Q1 and the
connection area to the MCU.
• Central power input should be fed in at the VDDA/VSSA pins.
Table 1-12. Recommended Component Values
Component Purpose Type Value
C1 VDD1 filter capacitor Ceramic X7R 220nF, 470nF(1)
1. In 48LQFP and 52LQFP package versions, VDD2 is not available. Thus 470nF must be connected to
VDD1.
C2 VDDR filter capacitor X7R/tantalum >=100nF
C3 VDDPLL filter capacitor Ceramic X7R 100nF
C4 PLL loop filter capacitor See PLL specification chapter
C5 PLL loop filter capacitor
C6 OSC load capacitor See PLL specification chapter
C7 OSC load capacitor
C8 VDD2 filter capacitor (80 QFP only) Ceramic X7R 220nF
C9 VDDA filter capacitor Ceramic X7R 100nF
C10 VDDX filter capacitor X7R/tantalum >=100nF
C11 DC cutoff capacitor Colpitts mode only, if recommended by
quartz manufacturer
R1 Pierce Mode Select Pullup Pierce Mode Only
R2 PLL loop filter resistor See PLL Specification chapter
R3 / RBPLL loop filter resistor Pierce mode only
R4 / RSPLL loop filter resistor
Q1 Quartz — —
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
66 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-15. Recommended PCB Layout (48 LQFP) Colpitts Oscillator
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 67
Rev 01.24
Figure 1-16. Recommended PCB Layout (52 LQFP) Colpitts Oscillator
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
68 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-17. Recommended PCB Layout (80 QFP) Colpitts Oscillator
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 69
Rev 01.24
Figure 1-18. Recommended PCB Layout for 48 LQFP Pierce Oscillator
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
70 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 1-19. Recommended PCB Layout for 52 LQFP Pierce Oscillator
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 71
Rev 01.24
Figure 1-20. Recommended PCB Layout for 80QFP Pierce Oscillator
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
72 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 73
Rev 01.24
Chapter 2
Port Integration Module (PIM9C32) Block Description
2.1 Introduction
The Port Integration Module establishes the interface between the peripheral modules and the I/O pins for
all ports.
This chapter covers:
• Port A, B, and E related to the core logic and the multiplexed bus interface
• Port T connected to the TIM module (PWM module can be routed to port T as well)
• Port S connected to the SCI module
• Port M associated to the MSCAN and SPI module
• Port P connected to the PWM module, external interrupt sources available
• Port J pins can be used as external interrupt sources and standard I/O’s
The following I/O pin configurations can be selected:
• Available on all I/O pins:
— Input/output selection
— Drive strength reduction
— Enable and select of pull resistors
• Available on all Port P and Port J pins:
— Interrupt enable and status flags
The implementation of the Port Integration Module is device dependent.
2.1.1 Features
A standard port has the following minimum features:
• Input/output selection
• 5-V output drive with two selectable drive strength
• 5-V digital and analog input
• Input with selectable pull-up or pull-down device
Optional features:
• Open drain for wired-OR connections
• Interrupt inputs with glitch filtering
Chapter 2 Port Integration Module (PIM9C32) Block Description
74 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.1.2 Block Diagram
Figure 2-1 is a block diagram of the PIM.
Figure 2-1. PIM Block Diagram
Note: The MODRR register within the PIM allows for mapping of PWM channels to Port T in the absence
of Port P pins for the low pin count packages. For the 80QFP package option it is recommended not to use
MODRR since this is intended to support PWM channel availability in low pin count packages. Note that
Port T
PT0
PT1
PT2
PT3
PT4
PT5
PT6
PT7
TIM
IOC0
IOC1
IOC2
IOC3
IOC4
IOC5
IOC6
IOC7
Port P
PP0
PP1
PP2
PP3
PP4
PP5
PP6
PP7
Port S
PS0
PS1
PM2
PM3
PM4
PM5
PM0
PM1
RXD
TXD
RXCAN
TXCAN
MISO
MOSI
SCK
SS
SCI
CAN
SPI
Port J
PJ7
Port Integration Module
IRQ Logic
Interrupt Logic
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port E
PE0
PE1
PE2
PE3
PE4
PE5
PE6
PE7
ADDR8/DATA8
ADDR9/DATA9
ADDR10/DATA10
ADDR11/DATA11
ADDR12/DATA12
ADDR13/DATA13
ADDR14/DATA14
ADDR15/DATA15
ADDR0/DATA0
ADDR1/DATA1
ADDR2/DATA2
ADDR3/DATA3
ADDR4/DATA4
ADDR5/DATA5
ADDR6/DATA6
ADDR7/DATA7
XIRQ
IRQ
R/W
LSTRB/TAGLO
ECLK
IPIPE0/MODA
NOACC/XCLKS
IPIPE1/MODB
CORE
BKGD/MODC/TAGHI BKGD
PJ6
Port M
A/D
PAD0
PAD1
PAD2
PAD3
PAD4
PAD5
PAD6
PAD7
ATD
AN0
AN1
AN2
AN3
AN4
AN5
AN6
AN7
PS2
PS3
PWM
PWM0
PWM1
PWM2
PWM3
PWM4
PWM5
MUX
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 75
Rev 01.24
when mapping PWM channels to Port T in an 80QFP option, the associated PWM channels are then
mapped to both Port P and Port T.
Chapter 2 Port Integration Module (PIM9C32) Block Description
76 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.2 Signal Description
This section lists and describes the signals that do connect off-chip.
Table 2-1 shows all pins and their functions that are controlled by the PIM module. If there is more than
one function associated to a pin, the priority is indicated by the position in the table from top (highest
priority) to down (lowest priority).
Table 2-1. Pin Functions and Priorities
Port Pin Name Pin Function Description Pin Function
after Reset
Port T PT[7:0] PWM[4:0] PWM outputs (only available if enabled in MODRR register) GPIO
IOC[7:0] Standard timer channels
GPIO General-purpose I/O
Port S PS3 GPIO General-purpose I/O
PS2 GPIO General purpose I/O
PS1 TXD Serial communication interface transmit pin
GPIO General-purpose I/O
PS0 RXD Serial communication interface receive pin
GPIO General-purpose I/O
Port M PM5 SCK SPI clock
PM4 MOSI SPI transmit pin
PM3 SS SPI slave select line
PM2 MISO SPI receive pin
PM1 TXCAN MSCAN transmit pin
PM0 RXCAN MSCAN receive pin
Port P PP[7:0] PWM[5:0] PWM outputs
GPIO[7:0] General purpose I/O with interrupt
PP[6] ROMON ROMON input signal
Port J PJ[7:6] GPIO General purpose I/O with interrupt
Port AD PAD[7:0] ATD[7:0] ATD analog inputs
GPIO[7:0] General purpose I/O
Port A PA[7:0] ADDR[15:8]/
DATA[15:8]/
GPIO
Refer to MEBI Block Guide.
Port B PB[7:0] ADDR[7:0]/
DATA[7:0]/
GPIO
Refer to MEBI Block Guide.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 77
Rev 01.24
2.3 Memory Map and Registers
This section provides a detailed description of all registers.
2.3.1 Module Memory Map
Figure 2-2 shows the register map of the Port Integration Module.
Port E
PE7
NOACC/
XCLKS/
GPIO
Refer to MEBI Block Guide.
PE6
IPIPE1/
MODB/
GPIO
PE5
IPIPE0/
MODA/
GPIO
PE4 ECLK/GPIO
PE3
LSTRB/
TAGLO/
GPIO
PE2 R/W/
GPIO
PE1 IRQ/GPI
PE0 XIRQ/GPI
Address Name Bit 7 654321Bit 0
0x0000 PTT
RPTT7 PTT6 PTT5 PTT4 PTT3 PTT2 PTT1 PTT0
W
TIM IOC7 IOC6 IOC5 IOC4 IOC3 IOC2 IOC1 IOC0
PWM PWM4 PWM3 PWM2 PWM1 PWM0
0x0001 PTIT R PTIT7 PTIT6 PTIT5 PTIT4 PTIT3 PTIT2 PTIT1 PTIT0
W
0x0002 DDRT RDDRT7 DDRT6 DDRT5 DDRT4 DDRT3 DDRT2 DDRT1 DDRT0
W
0x0003 RDRT RRDRT7 RDRT6 RDRT5 RDRT4 RDRT3 RDRT2 RDRT1 RDRT0
W
0x0004 PERT RPERT7 PERT6 PERT5 PERT4 PERT3 PERT2 PERT1 PERT0
W
0x0005 PPST RPPST7 PPST6 PPST5 PPST4 PPST3 PPST2 PPST1 PPST0
W
= Unimplemented or Reserved
Figure 2-2. Quick Reference to PIM Registers (Sheet 1 of 3)
Table 2-1. Pin Functions and Priorities (continued)
Port Pin Name Pin Function Description Pin Function
after Reset
Chapter 2 Port Integration Module (PIM9C32) Block Description
78 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x0006 Reserved R00000000
W
0x0007 MODRR R000
MODRR4 MODRR3 MODRR2 MODRR1 MODRR0
W
0x0008 PTS
R0000
PTS3 PTS2 PTS1 PTS0
W
SCI——————TXDRXD
0x0009 PTIS R0000PTIS3 PTIS2 PTIS1 PTIS0
W
0x000A DDRS R0000
DDRS3 DDRS2 DDRS1 DDRS0
W
0x000B RDRS R0000
RDRS3 RDRS2 RDRS1 RDRS0
W
0x000C PERS R0000
PERS3 PERS2 PERS1 PERS0
W
0x000D PPSS R0000
PPSS3 PPSS2 PPSS1 PPSS0
W
0x000E WOMS R0000
WOMS3 WOMS2 WOMS1 WOMS0
W
0x000F Reserved R00000000
W
0x0010 PTM
R0 0 PTM5 PTM4 PTM3 PTM2 PTM1 PTM0
W
MSCAN
/
SPI
— — SCK MOSI SS MISO TXCAN RXCAN
0x0011 PTIM R 0 0 PTIM5 PTIM4 PTIM3 PTIM2 PTIM1 PTIM0
W
0x0012 DDRM R0 0 DDRM5 DDRM4 DDRM3 DDRM2 DDRM1 DDRM0
W
0x0013 RDRM R0 0 RDRM5 RDRM4 RDRM3 RDRM2 RDRM1 RDRM0
W
0x0014 PERM R0 0 PERM5 PERM4 PERM3 PERM2 PERM1 PERM0
W
0x0015 PPSM R0 0 PPSM5 PPSM4 PPSM3 PPSM2 PPSM1 PPSM0
W
0x0016 WOMM R0 0 WOMM5 WOMM4 WOMM3 WOMM2 WOMM1 WOMM0
W
0x0017 Reserved R00000000
W
0x0018 PTP
RPTP7 PTP6 PTP5 PTP4 PTP3 PTP2 PTP1 PTP0
W
PWM — — PWM5 PWM4 PWM3 PWM2 PWM1 PWM0
0x0019 PTIP R PTIP7 PTIP6 PTIP5 PTIP4 PTIP3 PTIP2 PTIP1 PTIP0
W
Address Name Bit 7 654321Bit 0
= Unimplemented or Reserved
Figure 2-2. Quick Reference to PIM Registers (Sheet 2 of 3)
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 79
Rev 01.24
0x001A DDRP RDDRP7 DDRP6 DDRP5 DDRP4 DDRP3 DDRP2 DDRP1 DDRP0
W
0x001B RDRP RRDRP7 RDRP6 RDRP5 RDRP4 RDRP3 RDRP2 RDRP1 RDRP0
W
0x001C PERP RPERP7 PERP6 PERP5 PERP4 PERP3 PERP2 PERP1 PERP0
W
0x001D PPSP RPPSP7 PPSP6 PPSP5 PPSP4 PPSP3 PPSP2 PPSP1 PPSP0
W
0x001E PIEP RPIEP7 PIEP6 PIEP5 PIEP4 PIEP3 PIEP2 PIEP1 PIEP0
W
0x001F PIFP RPIFP7 PIFP6 PIFP5 PIFP4 PIFP3 PIFP2 PIFP1 PIFP0
W
0x0020–
0x0027 Reserved R00000000
W
0x0028 PTJ RPTJ7 PTJ6 000000
W
0x0029 PTIJ R PTIJ7 PTIJ6 000000
W
0x002A DDRJ RDDRJ7 DDRJ6 000000
W
0x002B RDRJ RRDRJ7 RDRJ6 000000
W
0x002C PERJ RPERJ7 PERJ6 000000
W
0x002D PPSJ RPPSJ7 PPSJ6 000000
W
0x002E PIEJ RPIEJ7 PIEJ6 000000
W
0x002F PIFJ RPIFJ7 PIFJ6 000000
W
0x0030 PTAD RPTAD7 PTAD6 PTAD5 PTAD4 PTAD3 PTAD2 PTAD1 PTAD0
W
0x0031 PTIAD R PTIAD7 PTIAD6 PTIAD5 PTIAD4 PTIAD3 PTIAD2 PTIAD1 PTIAD0
W
0x0032 DDRAD RDDRAD7 DDRAD6 DDRAD5 DDRAD4 DDRAD3 DDRAD2 DDRAD1 DDRAD0
W
0x0033 RDRAD RRDRAD7 RDRAD6 RDRAD5 RDRAD4 RDRAD3 RDRAD2 RDRAD1 RDRAD0
W
0x0034 PERAD RPERAD7 PERAD6 PERAD5 PERAD4 PERAD3 PERAD2 PERAD1 PERAD0
W
0x0035 PPSAD RPPSAD7 PPSAD6 PPSAD5 PPSAD4 PPSAD3 PPSAD2 PPSAD1 PPSAD0
W
0x0036–
0x003F Reserved R00000000
W
Address Name Bit 7 654321Bit 0
= Unimplemented or Reserved
Figure 2-2. Quick Reference to PIM Registers (Sheet 3 of 3)
Chapter 2 Port Integration Module (PIM9C32) Block Description
80 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2 Register Descriptions
Table 2-2 summarizes the effect on the various configuration bits — data direction (DDR), input/output
level (I/O), reduced drive (RDR), pull enable (PE), pull select (PS), and interrupt enable (IE) for the ports.
The configuration bit PS is used for two purposes:
1. Configure the sensitive interrupt edge (rising or falling), if interrupt is enabled.
2. Select either a pull-up or pull-down device if PE is active.
NOTE
All bits of all registers in this module are completely synchronous to internal
clocks during a register read.
Table 2-2. Pin Configuration Summary
DDR IO RDR PE PS IE(1)
1. Applicable only on ports P and J.
Function Pull Device Interrupt
0 X X 0 X 0 Input Disabled Disabled
0 X X 1 0 0 Input Pull up Disabled
0 X X 1 1 0 Input Pull down Disabled
0 X X 0 0 1 Input Disabled Falling edge
0 X X 0 1 1 Input Disabled Rising edge
0 X X 1 0 1 Input Pull up Falling edge
0 X X 1 1 1 Input Pull down rising edge
1 0 0 X X 0 Output, full drive to 0 Disabled Disabled
1 1 0 X X 0 Output, full drive to 1 Disabled Disabled
1 0 1 X X 0 Output, reduced drive to 0 Disabled Disabled
1 1 1 X X 0 Output, reduced drive to 1 Disabled Disabled
1 0 0 X 0 1 Output, full drive to 0 Disabled Falling edge
1 1 0 X 1 1 Output, full drive to 1 Disabled Rising edge
1 0 1 X 0 1 Output, reduced drive to 0 Disabled Falling edge
1 1 1 X 1 1 Output, reduced drive to 1 Disabled Rising edge
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 81
Rev 01.24
2.3.2.1 Port T Registers
2.3.2.1.1 Port T I/O Register (PTT)
Read: Anytime.
Write: Anytime.
If the data direction bits of the associated I/O pins are set to 1, a read returns the value of the port register,
otherwise the value at the pins is read.
If a TIM-channel is defined as output, the related port T is assigned to IOC function.
In addition to the possible timer functionality of port T pins PWM channels can be routed to port T. For
this the Module Routing Register (MODRR) needs to be configured.
Module Base + 0x0000
76543210
R
PTT7 PTT6 PTT5 PTT4 PTT3 PTT2 PTT1 PTT0
W
TIM IOC7 IOC6 IOC5 IOC4 IOC3 IOC2 IOC1 IOC0
PWM PWM4 PWM3 PWM2 PWM1 PWM0
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-3. Port T I/O Register (PTT)
Table 2-3. Port T[4:0] Pin Functionality Configurations(1)
1. All fields in the that are not shaded are standard use cases.
MODRR[x] PWME[x] TIMEN[x]
(2)
2. TIMEN[x] means that the timer is enabled (TSCR1[7]), the related channel is
configured for output compare function (TIOS[x] or special output on a timer
overflow event — configurable in TTOV[x]) and the timer output is routed to the
port pin (TCTL1/TCTL2).
Port T[x] Output
0 0 0 General Purpose I/O
0 0 1 Timer
0 1 0 General Purpose I/O
0 1 1 Timer
1 0 0 General Purpose I/O
1 0 1 Timer
1 1 0 PWM
1 1 1 PWM
Chapter 2 Port Integration Module (PIM9C32) Block Description
82 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.1.2 Port T Input Register (PTIT)
Read: Anytime.
Write: Never, writes to this register have no effect.
2.3.2.1.3 Port T Data Direction Register (DDRT)
Read: Anytime.
Write: Anytime.
Module Base + 0x0001
76543210
R PTIT7 PTIT6 PTIT5 PTIT4 PTIT3 PTIT2 PTIT1 PTIT0
W
Reset — — ——————
= Unimplemented or Reserved
Figure 2-4. Port T Input Register (PTIT)
Table 2-4. PTIT Field Descriptions
Field Description
7–0
PTIT[7:0]
Port T Input Register — This register always reads back the status of the associated pins. This can also be
used to detect overload or short circuit conditions on output pins.
Module Base + 0x0002
76543210
R
DDRT7 DDRT6 DDRT5 DDRT4 DDRT3 DDRT2 DDRT1 DDRT0
W
Reset 0 0 0 00000
Figure 2-5. Port T Data Direction Register (DDRT)
Table 2-5. DDRT Field Descriptions
Field Description
7–0
DDRT[7:0]
Data Direction Port T — This register configures each port T pin as either input or output.
The standard TIM / PWM modules forces the I/O state to be an output for each standard TIM / PWM module port
associated with an enabled output compare. In these cases the data direction bits will not change.
The DDRT bits revert to controlling the I/O direction of a pin when the associated timer output compare is
disabled.
The timer input capture always monitors the state of the pin.
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus cycles until the correct value is read on PTT
or PTIT registers, when changing the DDRT register.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 83
Rev 01.24
2.3.2.1.4 Port T Reduced Drive Register (RDRT)
Read: Anytime.
Write: Anytime.
2.3.2.1.5 Port T Pull Device Enable Register (PERT)
Read: Anytime.
Write: Anytime.
Module Base + 0x0003
76543210
R
RDRT7 RDRT6 RDRT5 RDRT4 RDRT3 RDRT2 RDRT1 RDRT0
W
Reset 0 0 0 00000
Figure 2-6. Port T Reduced Drive Register (RDRT)
Table 2-6. RDRT Field Descriptions
Field Description
7–0
RDRT[7:0]
Reduced Drive Port T — This register configures the drive strength of each port T output pin as either full or
reduced. If the port is used as input this bit is ignored.
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
Module Base + 0x0004
76543210
R
PERT7 PERT6 PERT5 PERT4 PERT3 PERT2 PERT1 PERT0
W
Reset 0 0 0 00000
Figure 2-7. Port T Pull Device Enable Register (PERT)
Table 2-7. PERT Field Descriptions
Field Description
7–0
PERT[7:0]
Pull Device Enable — This register configures whether a pull-up or a pull-down device is activated, if the port
is used as input. This bit has no effect if the port is used as output. Out of reset no pull device is enabled.
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
Chapter 2 Port Integration Module (PIM9C32) Block Description
84 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.1.6 Port T Polarity Select Register (PTTST)
Read: Anytime.
Write: Anytime.
2.3.2.1.7 Port T Module Routing Register (MODRR)
Read: Anytime.
Write: Anytime.
NOTE
MODRR[4] must be kept clear on devices featuring a 4 channel PWM.
Module Base + 0x0005
76543210
R
PPST7 PPST6 PPST5 PPST4 PPST3 PPST2 PPST1 PPST0
W
Reset 0 0 0 00000
Figure 2-8. Port T Polarity Select Register (PPST)
Table 2-8. PPST Field Descriptions
Field Description
7–0
PPST[7:0]
Pull Select Port T — This register selects whether a pull-down or a pull-up device is connected to the pin.
0 A pull-up device is connected to the associated port T pin, if enabled by the associated bit in register PERT
and if the port is used as input.
1 A pull-down device is connected to the associated port T pin, if enabled by the associated bit in register PERT
and if the port is used as input.
Module Base + 0x0007
76543210
R000
MODRR4 MODRR3 MODRR2 MODRR1 MODRR0
W
Reset — — — 00000
= Unimplemented or Reserved
Figure 2-9. Port T Module Routing Register (MODRR)
Table 2-9. MODRR Field Descriptions
Field Description
4–0
MODRR[4:0]
Module Routing Register Port T — This register selects the module connected to port T.
0 Associated pin is connected to TIM module
1 Associated pin is connected to PWM module
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 85
Rev 01.24
2.3.2.2 Port S Registers
2.3.2.2.1 Port S I/O Register (PTS)
Read: Anytime.
Write: Anytime.
If the data direction bits of the associated I/O pins are set to 1, a read returns the value of the port register,
otherwise the value at the pins is read.
The SCI port associated with transmit pin 1 is configured as output if the transmitter is enabled and the
SCI pin associated with receive pin 0 is configured as input if the receiver is enabled. Please refer to SCI
Block User Guide for details.
2.3.2.2.2 Port S Input Register (PTIS)
Read: Anytime.
Write: Never, writes to this register have no effect.
Module Base + 0x0008
76543210
R0000
PTS3 PTS2 PTS1 PTS0
W
SCI——————TXDRXD
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-10. Port S I/O Register (PTS)
Module Base + 0x0009
76543210
R 0 0 0 0 PTIS3 PTIS2 PTIS1 PTIS0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-11. Port S Input Register (PTIS)
Table 2-10. PTIS Field Descriptions
Field Description
3–0
PTIS[3:0]
Port S Input Register — This register always reads back the status of the associated pins. This also can be
used to detect overload or short circuit conditions on output pins.
Chapter 2 Port Integration Module (PIM9C32) Block Description
86 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.2.3 Port S Data Direction Register (DDRS)
Read: Anytime.
Write: Anytime.
Module Base + 0x000A
76543210
R0000
DDRS3 DDRS2 DDRS1 DDRS0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-12. Port S Data Direction Register (DDRS)
Table 2-11. DDRS Field Descriptions
Field Description
3–0
DDRS[3:0]
Direction Register Port S — This register configures each port S pin as either input or output.
If the associated SCI transmit or receive channel is enabled this register has no effect on the pins. The pin is
forced to be an output if the SCI transmit channel is enabled, it is forced to be an input if the SCI receive channel
is enabled.
The DDRS bits revert to controlling the I/O direction of a pin when the associated channel is disabled.
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus cycles until the correct value is read on PTS
or PTIS registers, when changing the DDRS register.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 87
Rev 01.24
2.3.2.2.4 Port S Reduced Drive Register (RDRS)
Read: Anytime.
Write: Anytime.
2.3.2.2.5 Port S Pull Device Enable Register (PERS)
Read: Anytime.
Write: Anytime.
Module Base + 0x000B
76543210
R0000
RDRS3 RDRS2 RDRS1 RDRS0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-13. Port S Reduced Drive Register (RDRS)
Table 2-12. RDRS Field Descriptions
Field Description
3–0
RDRS[3:0]
Reduced Drive Port S — This register configures the drive strength of each port S output pin as either full or
reduced. If the port is used as input this bit is ignored.
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
Module Base + 0x000C
76543210
R0000
PERS3 PERS2 PERS1 PERS0
W
Reset 0 0 0 01111
= Unimplemented or Reserved
Figure 2-14. Port S Pull Device Enable Register (PERS)
Table 2-13. PERS Field Descriptions
Field Description
3–0
PERS[3:0]
Reduced Drive Port S — This register configures whether a pull-up or a pull-down device is activated, if the port
is used as input or as output in wired-or (open drain) mode. This bit has no effect if the port is used as push-pull
output. Out of reset a pull-up device is enabled.
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
Chapter 2 Port Integration Module (PIM9C32) Block Description
88 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.2.6 Port S Polarity Select Register (PPSS)
Read: Anytime.
Write: Anytime.
2.3.2.2.7 Port S Wired-OR Mode Register (WOMS)
Read: Anytime.
Write: Anytime.
Module Base + 0x000D
76543210
R0000
PPSS3 PPSS2 PPSS1 PPSS0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-15. Port S Polarity Select Register (PPSS)
Table 2-14. PPSS Field Descriptions
Field Description
3–0
PPSS[3:0]
Pull Select Port S — This register selects whether a pull-down or a pull-up device is connected to the pin.
0 A pull-up device is connected to the associated port S pin, if enabled by the associated bit in register PERS
and if the port is used as input or as wired-or output.
1 A pull-down device is connected to the associated port S pin, if enabled by the associated bit in register PERS
and if the port is used as input.
Module Base + 0x000E
76543210
R0000
WOMS3 WOMS2 WOMS1 WOMS0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-16. Port S Wired-Or Mode Register (WOMS)
Table 2-15. WOMS Field Descriptions
Field Description
3–0
WOMS[3:0]
Wired-OR Mode Port S — This register configures the output pins as wired-or. If enabled the output is driven
active low only (open-drain). A logic level of “1” is not driven. This bit has no influence on pins used as inputs.
0 Output buffers operate as push-pull outputs.
1 Output buffers operate as open-drain outputs.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 89
Rev 01.24
2.3.2.3 Port M Registers
2.3.2.3.1 Port M I/O Register (PTM)
Read: Anytime.
Write: Anytime.
If the data direction bits of the associated I/O pins are set to 1, a read returns the value of the port register,
otherwise the value at the pins is read.
The SPI pin configurations (PM[5:2]) is determined by several status bits in the SPI module. Please refer
to the SPI Block User Guide for details.
2.3.2.3.2 Port M Input Register (PTIM)
Read: Anytime.
Write: Never, writes to this register have no effect.
Module Base + 0x0010
76543210
R0 0
PTM5 PTM4 PTM3 PTM2 PTM1 PTM0
W
MSCAN/
SPI — — SCK MOSI SS MISO TXCAN RXCAN
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-17. Port M I/O Register (PTM)
Module Base + 0x0011
76543210
R 0 0 PTIM5 PTIM4 PTIM3 PTIM2 PTIM1 PTIM0
W
Reset — — ——————
= Unimplemented or Reserved
Figure 2-18. Port M Input Register (PTIM)
Table 2-16. PTIM Field Descriptions
Field Description
5–0
PTIM[5:0]
Port M Input Register — This register always reads back the status of the associated pins. This also can be
used to detect overload or short circuit conditions on output pins.
Chapter 2 Port Integration Module (PIM9C32) Block Description
90 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.3.3 Port M Data Direction Register (DDRM)
Read: Anytime.
Write: Anytime.
Module Base + 0x0012
76543210
R0 0
DDRM5 DDRM4 DDRM3 DDRM2 DDRM1 DDRM0
W
Reset — — 0 00000
= Unimplemented or Reserved
Figure 2-19. Port M Data Direction Register (DDRM)
Table 2-17. DDRM Field Descriptions
Field Description
5–0
DDRM[5:0]
Data Direction Port M — This register configures each port S pin as either input or output
If SPI or MSCAN is enabled, the SPI and MSCAN modules determines the pin directions. Please refer to the SPI
and MSCAN Block User Guides for details.
If the associated SCI or MSCAN transmit or receive channels are enabled, this register has no effect on the pins.
The pins are forced to be outputs if the SCI or MSCAN transmit channels are enabled, they are forced to be inputs
if the SCI or MSCAN receive channels are enabled.
The DDRS bits revert to controlling the I/O direction of a pin when the associated channel is disabled.
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus cycles until the correct value is read on PTM
or PTIM registers, when changing the DDRM register.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 91
Rev 01.24
2.3.2.3.4 Port M Reduced Drive Register (RDRM)
Read: Anytime.
Write: Anytime.
2.3.2.3.5 Port M Pull Device Enable Register (PERM)
Read: Anytime.
Write: Anytime.
Module Base + 0x0013
76543210
R0 0
RDRM5 RDRM4 RDRM3 RDRM2 RDRM1 RDRM0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-20. Port M Reduced Drive Register (RDRM)
Table 2-18. RDRM Field Descriptions
Field Description
5–0
RDRM[5:0]
Reduced Drive Port M — This register configures the drive strength of each port M output pin as either full or
reduced. If the port is used as input this bit is ignored.
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
Module Base + 0x0014
76543210
R0 0
PERM5 PERM4 PERM3 PERM2 PERM1 PERM0
W
Reset 0 0 1 11111
= Unimplemented or Reserved
Figure 2-21. Port M Pull Device Enable Register (PERM)
Table 2-19. PERM Field Descriptions
Field Description
5–0
PERM[5:0]
Pull Device Enable Port M — This register configures whether a pull-up or a pull-down device is activated, if
the port is used as input or as output in wired-or (open drain) mode. This bit has no effect if the port is used as
push-pull output. Out of reset a pull-up device is enabled.
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
Chapter 2 Port Integration Module (PIM9C32) Block Description
92 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.3.6 Port M Polarity Select Register (PPSM)
Read: Anytime.
Write: Anytime.
2.3.2.3.7 Port M Wired-OR Mode Register (WOMM)
Read: Anytime.
Write: Anytime.
Module Base + 0x0015
76543210
R0 0
PPSM5 PPSM4 PPSM3 PPSM2 PPSM1 PPSM0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-22. Port M Polarity Select Register (PPSM)
Table 2-20. PPSM Field Descriptions
Field Description
5–0
PPSM[5:0]
Polarity Select Port M — This register selects whether a pull-down or a pull-up device is connected to the pin.
0 A pull-up device is connected to the associated port M pin, if enabled by the associated bit in register PERM
and if the port is used as input or as wired-or output.
1 A pull-down device is connected to the associated port M pin, if enabled by the associated bit in register PERM
and if the port is used as input.
Module Base + 0x0016
76543210
R0 0
WOMM5 WOMM4 WOMM3 WOMM2 WOMM1 WOMM0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-23. Port M Wired-OR Mode Register (WOMM)
Table 2-21. WOMM Field Descriptions
Field Description
5–0
WOMM[5:0]
Wired-OR Mode Port M — This register configures the output pins as wired-or. If enabled the output is driven
active low only (open-drain). A logic level of “1” is not driven. This bit has no influence on pins used as inputs.
0 Output buffers operate as push-pull outputs.
1 Output buffers operate as open-drain outputs.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 93
Rev 01.24
2.3.2.4 Port P Registers
2.3.2.4.1 Port P I/O Register (PTP)
Read: Anytime.
Write: Anytime.
If the data direction bits of the associated I/O pins are set to 1, a read returns the value of the port register,
otherwise the value at the pins is read.
2.3.2.4.2 Port P Input Register (PTIP)
Read: Anytime.
Write: Never, writes to this register have no effect.
This register always reads back the status of the associated pins. This can be also used to detect overload
or short circuit conditions on output pins.
Module Base + 0x0018
76543210
R
PTP7 PTP6 PTP5 PTP4 PTP3 PTP2 PTP1 PTP0
W
PWM — — PWM5 PWM4 PWM3 PWM2 PWM1 PWM0
Reset 0 0 0 00000
Figure 2-24. Port P I/O Register (PTP)
Module Base + 0x0019
76543210
R PTIP7 PTIP6 PTIP5 PTIP4 PTIP3 PTIP2 PTIP1 PTIP0
W
Reset — — ——————
= Unimplemented or Reserved
Figure 2-25. Port P Input Register (PTIP)
Chapter 2 Port Integration Module (PIM9C32) Block Description
94 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.4.3 Port P Data Direction Register (DDRP)
Read: Anytime.
Write: Anytime.
2.3.2.4.4 Port P Reduced Drive Register (RDRP)
Read: Anytime.
Write: Anytime.
Module Base + 0x001A
76543210
R
DDRP7 DDRP6 DDRP5 DDRP4 DDRP3 DDRP2 DDRP1 DDRP0
W
Reset 0 0 0 00000
Figure 2-26. Port P Data Direction Register (DDRP)
Table 2-22. DDRP Field Descriptions
Field Description
7–0
DDRP[7:0]
Data Direction Port P — This register configures each port P pin as either input or output.
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus cycles until the correct value is read on PTP
or PTIP registers, when changing the DDRP register.
Module Base + 0x001B
76543210
R
RDRP7 RDRP6 RDRP5 RDRP4 RDRP3 RDRP2 RDRP1 RDRP0
W
Reset 0 0 0 00000
Figure 2-27. Port P Reduced Drive Register (RDRP)
Table 2-23. RDRP Field Descriptions
Field Description
7–0
RDRP[7:0]
Reduced Drive Port P — This register configures the drive strength of each port P output pin as either full or
reduced. If the port is used as input this bit is ignored.
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 95
Rev 01.24
2.3.2.4.5 Port P Pull Device Enable Register (PERP)
Read: Anytime.
Write: Anytime.
2.3.2.4.6 Port P Polarity Select Register (PPSP)
Read: Anytime.
Write: Anytime.
Module Base + 0x001C
76543210
R
PERP7 PERP6 PERP5 PERP4 PERP3 PERP2 PERP1 PERP0
W
Reset 0 0 0 00000
Figure 2-28. Port P Pull Device Enable Register (PERP)
Table 2-24. PERP Field Descriptions
Field Description
7–0
PERP[7:0]
Pull Device Enable Port P — This register configures whether a pull-up or a pull-down device is activated, if the
port is used as input. This bit has no effect if the port is used as output. Out of reset no pull device is enabled.
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
Module Base + 0x001D
76543210
R
PPSP7 PPSP6 PPSP5 PPSP4 PPSP3 PPSP2 PPSP1 PPSP0
W
Reset 0 0 0 00000
Figure 2-29. Port P Polarity Select Register (PPSP)
Table 2-25. PPSP Field Descriptions
Field Description
7–0
PPSP[7:0]
Pull Select Port P — This register serves a dual purpose by selecting the polarity of the active interrupt edge
as well as selecting a pull-up or pull-down device if enabled.
0 Falling edge on the associated port P pin sets the associated flag bit in the PIFP register.A pull-up device is
connected to the associated port P pin, if enabled by the associated bit in register PERP and if the port is used
as input.
1 Rising edge on the associated port P pin sets the associated flag bit in the PIFP register.A pull-down device
is connected to the associated port P pin, if enabled by the associated bit in register PERP and if the port is
used as input.
Chapter 2 Port Integration Module (PIM9C32) Block Description
96 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.4.7 Port P Interrupt Enable Register (PIEP)
Read: Anytime.
Write: Anytime.
2.3.2.4.8 Port P Interrupt Flag Register (PIFP)
Read: Anytime.
Write: Anytime.
Module Base + 0x001E
76543210
R
PIEP7 PIEP6 PIEP5 PIEP4 PIEP3 PIEP2 PIEP1 PIEP0
W
Reset 0 0 0 00000
Figure 2-30. Port P Interrupt Enable Register (PIEP)
Table 2-26. PIEP Field Descriptions
Field Description
7–0
PIEP[7:0]
Pull Select Port P — This register disables or enables on a per pin basis the edge sensitive external interrupt
associated with port P.
0 Interrupt is disabled (interrupt flag masked).
1 Interrupt is enabled.
Module Base + 0x001F
76543210
R
PIFP7 PIFP6 PIFP5 PIFP4 PIFP3 PIFP2 PIFP1 PIFP0
W
Reset 0 0 0 00000
Figure 2-31. Port P Interrupt Flag Register (PIFP)
Table 2-27. PIFP Field Descriptions
Field Description
7–0
PIFP[7:0]
Interrupt Flags Port P — Each flag is set by an active edge on the associated input pin. This could be a rising
or a falling edge based on the state of the PPSP register. To clear this flag, write a “1” to the corresponding bit
in the PIFP register. Writing a “0” has no effect.
0 No active edge pending.
Writing a “0” has no effect.
1 Active edge on the associated bit has occurred (an interrupt will occur if the associated enable bit is set).
Writing a “1” clears the associated flag.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 97
Rev 01.24
2.3.2.5 Port J Registers
2.3.2.5.1 Port J I/O Register (PTJ)
Read: Anytime.
Write: Anytime.
If the data direction bits of the associated I/O pins are set to 1, a read returns the value of the port register,
otherwise the value at the pins is read.
2.3.2.5.2 Port J Input Register (PTIJ)
Read: Anytime.
Write: Never, writes to this register have no effect.
This register always reads back the status of the associated pins. This can be used to detect overload or
short circuit conditions on output pins.
Module Base + 0x0028
76543210
R
PTJ7 PTJ6
000000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-32. Port J I/O Register (PTJ)
Module Base + 0x0029
76543210
R PTIJ7 PTIJ6 0 00000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-33. Port J Input Register (PTIJ)
Chapter 2 Port Integration Module (PIM9C32) Block Description
98 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.5.3 Port J Data Direction Register (DDRJ)
Read: Anytime.
Write: Anytime.
2.3.2.5.4 Port J Reduced Drive Register (RDRJ)
Read: Anytime.
Write: Anytime.
Module Base + 0x002A
76543210
R
DDRJ7 DDRJ6
000000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-34. Port J Data Direction Register (DDRJ)
Table 2-28. DDRJ Field Descriptions
Field Description
7–6
DDRJ[7:6]
Data Direction Port J — This register configures port pins J[7:6] as either input or output.
DDRJ[7:6] — Data Direction Port J
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus cycles until the correct value is read on PTJ
or PTIJ registers, when changing the DDRJ register.
Module Base + 0x002B
76543210
R
RDRJ7 RDRJ6
000000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-35. Port J Reduced Drive Register (RDRJ)
Table 2-29. RDRJ Field Descriptions
Field Description
7–6
RDRJ[7:6]
Reduced Drive Port J — This register configures the drive strength of each port J output pin as either full or
reduced. If the port is used as input this bit is ignored.
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 99
Rev 01.24
2.3.2.5.5 Port J Pull Device Enable Register (PERJ)
Read: Anytime.
Write: Anytime.
2.3.2.5.6 Port J Polarity Select Register (PPSJ)
Read: Anytime.
Write: Anytime.
Module Base + 0x002C
76543210
R
PERJ7 PERJ6
000000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-36. Port J Pull Device Enable Register (PERJ)
Table 2-30. PERJ Field Descriptions
Field Description
7–6
PERJ[7:6]
Reduced Drive Port J — This register configures whether a pull-up or a pull-down device is activated, if the port
is used as input or as wired-or output. This bit has no effect if the port is used as push-pull output.
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
Module Base + 0x002D
76543210
R
PPSJ7 PPSJ6
000000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-37. Port J Polarity Select Register (PPSJ)
Table 2-31. PPSJ Field Descriptions
Field Description
7–6
PPSJ[7:6]
Reduced Drive Port J — This register serves a dual purpose by selecting the polarity of the active interrupt edge
as well as selecting a pull-up or pull-down device if enabled.
0 Falling edge on the associated port J pin sets the associated flag bit in the PIFJ register.
A pull-up device is connected to the associated port J pin, if enabled by the associated bit in register PERJ
and if the port is used as general purpose input.
1 Rising edge on the associated port J pin sets the associated flag bit in the PIFJ register.
A pull-down device is connected to the associated port J pin, if enabled by the associated bit in register PERJ
and if the port is used as input.
Chapter 2 Port Integration Module (PIM9C32) Block Description
100 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.5.7 Port J Interrupt Enable Register (PIEJ)
Read: Anytime.
Write: Anytime.
2.3.2.5.8 Port J Interrupt Flag Register (PIFJ)
Read: Anytime.
Write: Anytime.
Module Base + 0x002E
76543210
R
PIEJ7 PIEJ6
000000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-38. Port J Interrupt Enable Register (PIEJ)
Table 2-32. PIEJ Field Descriptions
Field Description
7–6
PIEJ[7:6]
Interrupt Enable Port J — This register disables or enables on a per pin basis the edge sensitive external
interrupt associated with port J.
0 Interrupt is disabled (interrupt flag masked).
1 Interrupt is enabled.
Module Base + 0x002F
76543210
R
PIFJ7 PIFJ6
000000
W
Reset 0 0 ——————
= Unimplemented or Reserved
Figure 2-39. Port J Interrupt Flag Register (PIFJ)
Table 2-33. PIFJ Field Descriptions
Field Description
7–6
PIFJ[7:6]
Interrupt Flags Port J — Each flag is set by an active edge on the associated input pin. This could be a rising
or a falling edge based on the state of the PPSJ register. To clear this flag, write “1” to the corresponding bit in
the PIFJ register. Writing a “0” has no effect.
0 No active edge pending.
Writing a “0” has no effect.
1 Active edge on the associated bit has occurred (an interrupt will occur if the associated enable bit is set).
Writing a “1” clears the associated flag.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 101
Rev 01.24
2.3.2.6 Port AD Registers
2.3.2.6.1 Port AD I/O Register (PTAD)
Read: Anytime.
Write: Anytime.
If the data direction bits of the associated I/O pins are set to 1, a read returns the value of the port register,
otherwise the value at the pins is read.
2.3.2.6.2 Port AD Input Register (PTIAD)
Read: Anytime.
Write: Never, writes to this register have no effect.
This register always reads back the status of the associated pins. This can be used to detect overload or
short circuit conditions on output pins.
Module Base + 0x0030
76543210
R
PTAD7 PTAD6 PTAD5 PTAD4 PTAD3 PTAD2 PTAD1 PTAD0
W
Reset 0 0 0 00000
Figure 2-40. Port AD I/O Register (PTAD)
Module Base + 0x0031
76543210
R PTIAD7 PTIAD6 PTIAD5 PTIAD4 PTIAD3 PTIAD2 PTIAD1 PTIAD0
W
Reset — — ——————
= Unimplemented or Reserved
Figure 2-41. Port AD Input Register (PTIAD)
Chapter 2 Port Integration Module (PIM9C32) Block Description
102 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.3.2.6.3 Port AD Data Direction Register (DDRAD)
Read: Anytime.
Write: Anytime.
2.3.2.6.4 Port AD Reduced Drive Register (RDRAD)
Read: Anytime.
Write: Anytime.
Module Base + 0x0032
76543210
R
DDRAD7 DDRAD6 DDRAD5 DDRAD4 DDRAD3 DDRAD2 DDRAD1 DDRAD0
W
Reset 0 0 0 00000
Figure 2-42. Port AD Data Direction Register (DDRAD)
Table 2-34. DDRAD Field Descriptions
Field Description
7–0
DDRAD[7:0]
Data Direction Port AD — This register configures port pins AD[7:0] as either input or output.
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus cycles until the correct value is read on
PTAD or PTIAD registers, when changing the DDRAD register.
Module Base + 0x0033
76543210
R
RDRAD7 RDRAD6 RDRAD5 RDRAD4 RDRAD3 RDRAD2 RDRAD1 RDRAD0
W
Reset 0 0 0 00000
Figure 2-43. Port AD Reduced Drive Register (RDRAD)
Table 2-35. RDRAD Field Descriptions
Field Description
7–0
RDRAD[7:0]
Reduced Drive Port AD — This register configures the drive strength of each port AD output pin as either full
or reduced. If the port is used as input this bit is ignored.
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 103
Rev 01.24
2.3.2.6.5 Port AD Pull Device Enable Register (PERAD)
Read: Anytime.
Write: Anytime.
2.3.2.6.6 Port AD Polarity Select Register (PPSAD)
Read: Anytime.
Write: Anytime.
Module Base + 0x0034
76543210
R
PERAD7 PERAD6 PERAD5 PERAD4 PERAD3 PERAD2 PERAD1 PERAD0
W
Reset 0 0 0 00000
Figure 2-44. Port AD Pull Device Enable Register (PERAD)
Table 2-36. PERAD Field Descriptions
Field Description
7–0
PERAD[7:0]
Pull Device Enable Port AD — This register configures whether a pull-up or a pull-down device is activated, if
the port is used as input. This bit has no effect if the port is used as output. Out of reset no pull device is enabled.
It is not possible to enable pull devices when a associated ATD channel is enabled simultaneously.
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
Module Base + 0x0035
76543210
R
PPSAD7 PPSAD6 PPSAD5 PPSAD4 PPSAD3 PPSAD2 PPSAD1 PPSAD0
W
Reset 0 0 0 00000
Figure 2-45. Port AD Polarity Select Register (PPSAD)
Table 2-37. PPSAD Field Descriptions
Field Description
7–0
PPSAD[7:0]
Pull Select Port AD — This register selects whether a pull-down or a pull-up device is connected to the pin.
0 A pull-up device is connected to the associated port AD pin, if enabled by the associated bit in register PERAD
and if the port is used as input.
1 A pull-down device is connected to the associated port AD pin, if enabled by the associated bit in register
PERAD and if the port is used as input.
Chapter 2 Port Integration Module (PIM9C32) Block Description
104 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.4 Functional Description
Each pin can act as general purpose I/O. In addition the pin can act as an output from a peripheral module
or an input to a peripheral module.
A set of configuration registers is common to all ports. All registers can be written at any time, however a
specific configuration might not become active.
Example: Selecting a pull-up resistor. This resistor does not become active while the port is used as a push-
pull output.
2.4.1 Registers
2.4.1.1 I/O Register
This register holds the value driven out to the pin if the port is used as a general purpose I/O. Writing to
this register has only an effect on the pin if the port is used as general purpose output. When reading this
address, the value of the pins are returned if the data direction register bits are set to 0.
If the data direction register bits are set to 1, the contents of the I/O register is returned. This is independent
of any other configuration (Figure 2-46).
Figure 2-46. Illustration of I/O Pin Functionality
2.4.1.2 Input Register
This is a read-only register and always returns the value of the pin (Figure 2-46).
2.4.1.3 Data Direction Register
This register defines whether the pin is used as an input or an output. If a peripheral module controls the
pin the contents of the data direction register is ignored (Figure 2-46).
PT
DDR
Output Enable
Module Enable
1
0
1
1
0
0
PAD
PTI
Data Out
Module
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 105
Rev 01.24
2.4.1.4 Reduced Drive Register
If the port is used as an output the register allows the configuration of the drive strength.
2.4.1.5 Pull Device Enable Register
This register turns on a pull-up or pull-down device. It becomes only active if the pin is used as an input
or as a wired-or output.
2.4.1.6 Polarity Select Register
This register selects either a pull-up or pull-down device if enabled. It becomes only active if the pin is
used as an input. A pull-up device can be activated if the pin is used as a wired-OR output.
2.4.2 Port Descriptions
2.4.2.1 Port T
This port is associated with the Standard Capture Timer. PWM output channels can be rerouted from port
P to port pins T. In all modes, port T pins can be used for either general-purpose I/O, Standard Capture
Timer I/O or as PWM channels module, if so configured by MODRR.
During reset, port T pins are configured as high-impedance inputs.
2.4.2.2 Port S
This port is associated with the serial SCI module. Port S pins PS[3:0] can be used either for general-
purpose I/O, or with the SCI subsystem.
During reset, port S pins are configured as inputs with pull-up.
2.4.2.3 Port M
This port is associated with the MSCAN and SPI module. Port M pins PM[5:0] can be used either for
general-purpose I/O, with the MSCAN or SPI subsystems.
During reset, port M pins are configured as inputs with pull-up.
2.4.2.4 Port AD
This port is associated with the ATD module. Port AD pins can be used either for general-purpose I/O, or
for the ATD subsystem. There are 2 data port registers associated with the Port AD: PTAD[7:0], located
in the PIM and PORTAD[7:0] located in the ATD.
To use PTAD[n] as a standard input port, the corresponding DDRD[n] must be cleared. To use PTAD[n]
as a standard output port, the corresponding DDRD[n] must be set
NOTE: To use PORTAD[n], located in the ATD as an input port register, DDRD[n] must be cleared and
ATDDIEN[n] must be set. Please refer to ATD Block Guide for details.
Chapter 2 Port Integration Module (PIM9C32) Block Description
106 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.4.2.5 Port P
The PWM module is connected to port P. Port P pins can be used as PWM outputs. Further the Keypad
Wake-Up function is implemented on pins PP[7:0]. During reset, port P pins are configured as high-
impedance inputs.
Port P offers 8 general purpose I/O pins with edge triggered interrupt capability in wired-or fashion. The
interrupt enable as well as the sensitivity to rising or falling edges can be individually configured on per
pin basis. All 8 bits/pins share the same interrupt vector. Interrupts can be used with the pins configured
as inputs or outputs.
An interrupt is generated when a bit in the port interrupt flag register and its corresponding port interrupt
enable bit are both set. This external interrupt feature is capable to wake up the CPU when it is in STOP
or WAIT mode.
A digital filter on each pin prevents pulses (Figure 2-48) shorter than a specified time from generating an
interrupt. The minimum time varies over process conditions, temperature and voltage (Figure 2-47 and
Table 2-38).
Figure 2-47. Interrupt Glitch Filter on Port P and J (PPS = 0)
Figure 2-48. Pulse Illustration
Table 2-38. Pulse Detection Criteria
Pulse
STOP Mode STOP(1) Mode
1. These values include the spread of the oscillator frequency over temperature,
voltage and process.
Value Unit Value Unit
Ignored tpign <= 3 Bus clocks tpign <= 3.2 µs
Uncertain 3 < tpulse < 4 Bus clocks 3.2 < tpulse < 10 µs
Valid tpval >= 4 Bus clocks tpval >= 10 µs
Glitch, filtered out, no interrupt flag set
Valid pulse, interrupt flag set
tpign
tpval
tpulse
Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 107
Rev 01.24
A valid edge on input is detected if 4 consecutive samples of a passive level are followed by 4 consecutive
samples of an active level directly or indirectly.
The filters are continuously clocked by the bus clock in RUN and WAIT mode. In STOP mode the clock
is generated by a single RC oscillator in the Port Integration Module. To maximize current saving the RC
oscillator runs only if the following condition is true on any pin:
Sample count <= 4 and port interrupt enabled (PIE=1) and port interrupt flag not set (PIF=0).
2.4.2.6 Port J
In all modes, port J pins PJ[7:6] can be used for general purpose I/O or interrupt driven general purpose
I/O’s. During reset, port J pins are configured as inputs.
Port J offers 2 I/O ports with the same interrupt features as on port P.
2.4.3 Port A, B, E and BKGD Pin
All port and pin logic is located in the core module. Please refer to S12_mebi Block User Guide for details.
2.4.4 External Pin Descriptions
All ports start up as general purpose inputs on reset.
2.4.5 Low Power Options
2.4.5.1 Run Mode
No low power options exist for this module in run mode.
2.4.5.2 Wait Mode
No low power options exist for this module in wait mode.
2.4.5.3 Stop Mode
All clocks are stopped. There are asynchronous paths to generate interrupts from STOP on port P and J.
2.5 Initialization Information
The reset values of all registers are given in Section 2.3.2, “Register Descriptions”.
2.5.1 Reset Initialization
All registers including the data registers get set/reset asynchronously. Table 2-39 summarizes the port
properties after reset initialization.
Chapter 2 Port Integration Module (PIM9C32) Block Description
108 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2.6 Interrupts
Port P and J generate a separate edge sensitive interrupt if enabled.
2.6.1 Interrupt Sources
NOTE
Vector addresses and their relative interrupt priority are determined at the
MCU level.
2.6.2 Recovery from STOP
The PIM can generate wake-up interrupts from STOP on port P and J. For other sources of external
interrupts please refer to the respective Block User Guide.
2.7 Application Information
It is not recommended to write PORTx and DDRx in a word access. When changing the register pins from
inputs to outputs, the data may have extra transitions during the write access. Initialize the port data register
before enabling the outputs.
Power consumption will increase the more the voltages on general purpose input pins deviate from the
supply voltages towards mid-range because the digital input buffers operate in the linear region.
Table 2-39. Port Reset State Summary
Port
Reset States
Data Direction Pull Mode Reduced Drive Wired-OR Mode Interrupt
T Input Hi-z Disabled n/a n/a
S Input Pull up Disabled Disabled n/a
M Input Pull up Disabled Disabled n/a
P Input Hi-z Disabled n/a Disabled
J Input Hi-z Disabled n/a Disabled
A
Refer to MEBI Block Guide for details.
B
E
BKGD pin Refer to BDM Block Guide for details.
Table 2-40. Port Integration Module Interrupt Sources
Interrupt Source Interrupt Flag Local Enable Global (CCR) Mask
Port P PIFP[7:0] PIEP[7:0] I Bit
Port J PIFJ[7:6] PIEJ[7:6] I Bit
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 109
Rev 01.24
Chapter 3
Module Mapping Control (MMCV4) Block Description
3.1 Introduction
This section describes the functionality of the module mapping control (MMC) sub-block of the S12 core
platform.
The block diagram of the MMC is shown in Figure 3-1.
Figure 3-1. MMC Block Diagram
The MMC is the sub-module which controls memory map assignment and selection of internal resources
and external space. Internal buses between the core and memories and between the core and peripherals is
controlled in this module. The memory expansion is generated in this module.
MMC
MODE INFORMATION
REGISTERS
CPU WRITE DATA BUS
CPU ADDRESS BUS
CPU CONTROL
STOP, WAIT
ADDRESS DECODE
CPU READ DATA BUS
EBI ALTERNATE ADDRESS BUS
EBI ALTERNATE WRITE DATA BUS
EBI ALTERNATE READ DATA BUS
SECURITY
CLOCKS, RESET
READ & WRITE ENABLES
ALTERNATE ADDRESS BUS (BDM)
ALTERNATE WRITE DATA BUS (BDM)
ALTERNATE READ DATA BUS (BDM)
CORE SELECT (S)
PORT K INTERFACE
MEMORY SPACE SELECT(S)
PERIPHERAL SELECT
BUS CONTROL
SECURE
BDM_UNSECURE
MMC_SECURE
INTERNAL MEMORY
EXPANSION
Chapter 3 Module Mapping Control (MMCV4) Block Description
110 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
3.1.1 Features
• Registers for mapping of address space for on-chip RAM, EEPROM, and FLASH (or ROM)
memory blocks and associated registers
• Memory mapping control and selection based upon address decode and system operating mode
• Core address bus control
• Core data bus control and multiplexing
• Core security state decoding
• Emulation chip select signal generation (ECS)
• External chip select signal generation (XCS)
• Internal memory expansion
• External stretch and ROM mapping control functions via the MISC register
• Reserved registers for test purposes
• Configurable system memory options defined at integration of core into the system-on-a-chip
(SoC).
3.1.2 Modes of Operation
Some of the registers operate differently depending on the mode of operation (i.e., normal expanded wide,
special single chip, etc.). This is best understood from the register descriptions.
3.2 External Signal Description
All interfacing with the MMC sub-block is done within the core, it has no external signals.
3.3 Memory Map and Register Definition
A summary of the registers associated with the MMC sub-block is shown in Figure 3-2. Detailed
descriptions of the registers and bits are given in the subsections that follow.
3.3.1 Module Memory Map
Table 3-1. MMC Memory Map
Address
Offset Register Access
0x0010 Initialization of Internal RAM Position Register (INITRM) R/W
0x0011 Initialization of Internal Registers Position Register (INITRG) R/W
0x0012 Initialization of Internal EEPROM Position Register (INITEE) R/W
0x0013 Miscellaneous System Control Register (MISC) R/W
0x0014 Reserved —
.
.
.
.
—
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 111
Rev 01.24
0x0017 Reserved —
.
.
.
.
—
0x001C Memory Size Register 0 (MEMSIZ0) R
0x001D Memory Size Register 1 (MEMSIZ1) R
.
.
.
.
0x0030 Program Page Index Register (PPAGE) R/W
0x0031 Reserved —
Table 3-1. MMC Memory Map (continued)
Address
Offset Register Access
Chapter 3 Module Mapping Control (MMCV4) Block Description
112 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
3.3.2 Register Descriptions
Name Bit 7 6 5 4321Bit 0
0x0010
INITRM
RRAM15 RAM14 RAM13 RAM12 RAM11 00
RAMHAL
W
0x0011
INITRG
R0 REG14 REG13 REG12 REG11 000
W
0x0012
INITEE
REE15 EE14 EE13 EE12 EE11 00
EEON
W
0x0013
MISC
R0000
EXSTR1 EXSTR0 ROMHM ROMON
W
0x0014
MTSTO
R Bit 7 6 5 4321Bit 0
W
0x0017
MTST1
R Bit 7 6 5 4321Bit 0
W
0x001C
MEMSIZ0
R REG_SW0 0 EEP_SW1 EEP_SW0 0 RAM_SW2 RAM_SW1 RAM_SW0
W
0x001D
MEMSIZ1
R ROM_SW1 ROM_SW0 0 0 0 0 PAG_SW1 PAG_SW0
W
0x0030
PPAGE
R0 0 PIX5 PIX4 PIX3 PIX2 PIX1 PIX0
W
0x0031
Reserved
R00000000
W
= Unimplemented
Figure 3-2. MMC Register Summary
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 113
Rev 01.24
3.3.2.1 Initialization of Internal RAM Position Register (INITRM)
Read: Anytime
Write: Once in normal and emulation modes, anytime in special modes
NOTE
Writes to this register take one cycle to go into effect.
This register initializes the position of the internal RAM within the on-chip system memory map.
Module Base + 0x0010
Starting address location affected by INITRG register setting.
76543210
R
RAM15 RAM14 RAM13 RAM12 RAM11
00
RAMHAL
W
Reset 0 0 0 01001
= Unimplemented or Reserved
Figure 3-3. Initialization of Internal RAM Position Register (INITRM)
Table 3-2. INITRM Field Descriptions
Field Description
7:3
RAM[15:11]
Internal RAM Map Position — These bits determine the upper five bits of the base address for the system’s
internal RAM array.
0
RAMHAL
RAM High-Align — RAMHAL specifies the alignment of the internal RAM array.
0 Aligns the RAM to the lowest address (0x0000) of the mappable space
1 Aligns the RAM to the higher address (0xFFFF) of the mappable space
Chapter 3 Module Mapping Control (MMCV4) Block Description
114 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
3.3.2.2 Initialization of Internal Registers Position Register (INITRG)
Read: Anytime
Write: Once in normal and emulation modes and anytime in special modes
This register initializes the position of the internal registers within the on-chip system memory map. The
registers occupy either a 1K byte or 2K byte space and can be mapped to any 2K byte space within the first
32K bytes of the system’s address space.
Module Base + 0x0011
Starting address location affected by INITRG register setting.
76543210
R0
REG14 REG13 REG12 REG11
000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 3-4. Initialization of Internal Registers Position Register (INITRG)
Table 3-3. INITRG Field Descriptions
Field Description
6:3
REG[14:11]
Internal Register Map Position — These four bits in combination with the leading zero supplied by bit 7 of
INITRG determine the upper five bits of the base address for the system’s internal registers (i.e., the minimum
base address is 0x0000 and the maximum is 0x7FFF).
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 115
Rev 01.24
3.3.2.3 Initialization of Internal EEPROM Position Register (INITEE)
Read: Anytime
Write: The EEON bit can be written to any time on all devices. Bits E[11:15] are “write anytime in all
modes” on most devices. On some devices, bits E[11:15] are “write once in normal and emulation modes
and write anytime in special modes”. See device overview chapter to determine the actual write access
rights.
NOTE
Writes to this register take one cycle to go into effect.
This register initializes the position of the internal EEPROM within the on-chip system memory map.
Module Base + 0x0012
Starting address location affected by INITRG register setting.
76543210
R
EE15 EE14 EE13 EE12 EE11
00
EEON
W
Reset1————————
1. The reset state of this register is controlled at chip integration. Please refer to the device overview section to determine the
actual reset state of this register.
= Unimplemented or Reserved
Figure 3-5. Initialization of Internal EEPROM Position Register (INITEE)
Table 3-4. INITEE Field Descriptions
Field Description
7:3
EE[15:11]
Internal EEPROM Map Position — These bits determine the upper five bits of the base address for the system’s
internal EEPROM array.
0
EEON
Enable EEPROM — This bit is used to enable the EEPROM memory in the memory map.
0 Disables the EEPROM from the memory map.
1 Enables the EEPROM in the memory map at the address selected by EE[15:11].
Chapter 3 Module Mapping Control (MMCV4) Block Description
116 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
3.3.2.4 Miscellaneous System Control Register (MISC)
Read: Anytime
Write: As stated in each bit description
NOTE
Writes to this register take one cycle to go into effect.
This register initializes miscellaneous control functions.
Module Base + 0x0013
Starting address location affected by INITRG register setting.
76543210
R0000
EXSTR1 EXSTR0 ROMHM ROMON
W
Reset: Expanded
or Emulation 0000110—
1
Reset: Peripheral
or Single Chip 00001101
Reset: Special Test 00001100
1. The reset state of this bit is determined at the chip integration level.
= Unimplemented or Reserved
Figure 3-6. Miscellaneous System Control Register (MISC)
Table 3-5. INITEE Field Descriptions
Field Description
3:2
EXSTR[1:0]
External Access Stretch Bits 1 and 0
Write: once in normal and emulation modes and anytime in special modes
This two-bit field determines the amount of clock stretch on accesses to the external address space as shown in
Table 3-6. In single chip and peripheral modes these bits have no meaning or effect.
1
ROMHM
FLASH EEPROM or ROM Only in Second Half of Memory Map
Write: once in normal and emulation modes and anytime in special modes
0 The fixed page(s) of FLASH EEPROM or ROM in the lower half of the memory map can be accessed.
1 Disables direct access to the FLASH EEPROM or ROM in the lower half of the memory map. These physical
locations of the FLASH EEPROM or ROM remain accessible through the program page window.
0
ROMON
ROMON — Enable FLASH EEPROM or ROM
Write: once in normal and emulation modes and anytime in special modes
This bit is used to enable the FLASH EEPROM or ROM memory in the memory map.
0 Disables the FLASH EEPROM or ROM from the memory map.
1 Enables the FLASH EEPROM or ROM in the memory map.
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 117
Rev 01.24
3.3.2.5 Reserved Test Register 0 (MTST0)
Read: Anytime
Write: No effect — this register location is used for internal test purposes.
3.3.2.6 Reserved Test Register 1 (MTST1)
Read: Anytime
Write: No effect — this register location is used for internal test purposes.
Table 3-6. External Stretch Bit Definition
Stretch Bit EXSTR1 Stretch Bit EXSTR0 Number of E Clocks Stretched
00 0
01 1
10 2
11 3
Module Base + 0x0014
Starting address location affected by INITRG register setting.
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 3-7. Reserved Test Register 0 (MTST0)
Module Base + 0x0017
Starting address location affected by INITRG register setting.
76543210
R00000000
W
Reset 0 0 0 10000
= Unimplemented or Reserved
Figure 3-8. Reserved Test Register 1 (MTST1)
Chapter 3 Module Mapping Control (MMCV4) Block Description
118 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
3.3.2.7 Memory Size Register 0 (MEMSIZ0)
Read: Anytime
Write: Writes have no effect
Reset: Defined at chip integration, see device overview section.
The MEMSIZ0 register reflects the state of the register, EEPROM and RAM memory space configuration
switches at the core boundary which are configured at system integration. This register allows read
visibility to the state of these switches.
Module Base + 0x001C
Starting address location affected by INITRG register setting.
76543210
R REG_SW0 0 EEP_SW1 EEP_SW0 0 RAM_SW2 RAM_SW1 RAM_SW0
W
Reset — — ——————
= Unimplemented or Reserved
Figure 3-9. Memory Size Register 0 (MEMSIZ0)
Table 3-7. MEMSIZ0 Field Descriptions
Field Description
7
REG_SW0
Allocated System Register Space
0 Allocated system register space size is 1K byte
1 Allocated system register space size is 2K byte
5:4
EEP_SW[1:0]
Allocated System EEPROM Memory Space — The allocated system EEPROM memory space size is as
given in Table 3-8.
2
RAM_SW[2:0]
Allocated System RAM Memory Space — The allocated system RAM memory space size is as given in
Table 3-9.
Table 3-8. Allocated EEPROM Memory Space
eep_sw1:eep_sw0 Allocated EEPROM Space
00 0K byte
01 2K bytes
10 4K bytes
11 8K bytes
Table 3-9. Allocated RAM Memory Space
ram_sw2:ram_sw0 Allocated
RAM Space
RAM
Mappable Region
INITRM
Bits Used
RAM Reset
Base Address(1)
000 2K bytes 2K bytes RAM[15:11] 0x0800
001 4K bytes 4K bytes RAM[15:12] 0x0000
010 6K bytes 8K bytes(2) RAM[15:13] 0x0800
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 119
Rev 01.24
NOTE
As stated, the bits in this register provide read visibility to the system
physical memory space allocations defined at system integration. The actual
array size for any given type of memory block may differ from the allocated
size. Please refer to the device overview chapter for actual sizes.
3.3.2.8 Memory Size Register 1 (MEMSIZ1)
Read: Anytime
Write: Writes have no effect
Reset: Defined at chip integration, see device overview section.
The MEMSIZ1 register reflects the state of the FLASH or ROM physical memory space and paging
switches at the core boundary which are configured at system integration. This register allows read
visibility to the state of these switches.
011 8K bytes 8K bytes RAM[15:13] 0x0000
100 10K bytes 16K bytes 2RAM[15:14] 0x1800
101 12K bytes 16K bytes 2RAM[15:14] 0x1000
110 14K bytes 16K bytes 2RAM[15:14] 0x0800
111 16K bytes 16K bytes RAM[15:14] 0x0000
1. The RAM Reset BASE Address is based on the reset value of the INITRM register, 0x0009.
2. Alignment of the Allocated RAM space within the RAM mappable region is dependent on the value of RAMHAL.
Module Base + 0x001D
Starting address location affected by INITRG register setting.
76543210
R ROM_SW1 ROM_SW0 0 0 0 0 PAG_SW1 PAG_SW0
W
Reset — — ——————
= Unimplemented or Reserved
Figure 3-10. Memory Size Register 1 (MEMSIZ1)
Table 3-9. Allocated RAM Memory Space (continued)
ram_sw2:ram_sw0 Allocated
RAM Space
RAM
Mappable Region
INITRM
Bits Used
RAM Reset
Base Address(1)
Chapter 3 Module Mapping Control (MMCV4) Block Description
120 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
NOTE
As stated, the bits in this register provide read visibility to the system
memory space and on-chip/off-chip partitioning allocations defined at
system integration. The actual array size for any given type of memory
block may differ from the allocated size. Please refer to the device overview
chapter for actual sizes.
Table 3-10. MEMSIZ0 Field Descriptions
Field Description
7:6
ROM_SW[1:0]
Allocated System FLASH or ROM Physical Memory Space — The allocated system FLASH or ROM
physical memory space is as given in Table 3-11.
1:0
PAG_SW[1:0]
Allocated Off-Chip FLASH or ROM Memory Space — The allocated off-chip FLASH or ROM memory space
size is as given in Table 3-12.
Table 3-11. Allocated FLASH/ROM Physical Memory Space
rom_sw1:rom_sw0 Allocated FLASH
or ROM Space
00 0K byte
01 16K bytes
10 48K bytes(1)
11 64K bytes(1)
NOTES:
1. The ROMHM software bit in the MISC register determines the accessibility of the
FLASH/ROM memory space. Please refer to Section 3.3.2.8, “Memory Size Register 1
(MEMSIZ1),” for a detailed functional description of the ROMHM bit.
Table 3-12. Allocated Off-Chip Memory Options
pag_sw1:pag_sw0 Off-Chip Space On-Chip Space
00 876K bytes 128K bytes
01 768K bytes 256K bytes
10 512K bytes 512K bytes
11 0K byte 1M byte
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 121
Rev 01.24
3.3.2.9 Program Page Index Register (PPAGE)
Read: Anytime
Write: Determined at chip integration. Generally it’s: “write anytime in all modes;” on some devices it will
be: “write only in special modes.” Check specific device documentation to determine which applies.
Reset: Defined at chip integration as either 0x00 (paired with write in any mode) or 0x3C (paired with
write only in special modes), see device overview chapter.
The HCS12 core architecture limits the physical address space available to 64K bytes. The program page
index register allows for integrating up to 1M byte of FLASH or ROM into the system by using the six
page index bits to page 16K byte blocks into the program page window located from 0x8000 to 0xBFFF
as defined in Table 3-14. CALL and RTC instructions have special access to read and write this register
without using the address bus.
NOTE
Normal writes to this register take one cycle to go into effect. Writes to this
register using the special access of the CALL and RTC instructions will be
complete before the end of the associated instruction.
Module Base + 0x0030
Starting address location affected by INITRG register setting.
76543210
R0 0
PIX5 PIX4 PIX3 PIX2 PIX1 PIX0
W
Reset1————————
1. The reset state of this register is controlled at chip integration. Please refer to the device overview section to determine the
actual reset state of this register.
= Unimplemented or Reserved
Figure 3-11. Program Page Index Register (PPAGE)
Table 3-13. MEMSIZ0 Field Descriptions
Field Description
5:0
PIX[5:0]
Program Page Index Bits 5:0 — These page index bits are used to select which of the 64 FLASH or ROM
array pages is to be accessed in the program page window as shown in Table 3-14.
Chapter 3 Module Mapping Control (MMCV4) Block Description
122 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
3.4 Functional Description
The MMC sub-block performs four basic functions of the core operation: bus control, address decoding
and select signal generation, memory expansion, and security decoding for the system. Each aspect is
described in the following subsections.
3.4.1 Bus Control
The MMC controls the address bus and data buses that interface the core with the rest of the system. This
includes the multiplexing of the input data buses to the core onto the main CPU read data bus and control
of data flow from the CPU to the output address and data buses of the core. In addition, the MMC manages
all CPU read data bus swapping operations.
3.4.2 Address Decoding
As data flows on the core address bus, the MMC decodes the address information, determines whether the
internal core register or firmware space, the peripheral space or a memory register or array space is being
addressed and generates the correct select signal. This decoding operation also interprets the mode of
operation of the system and the state of the mapping control registers in order to generate the proper select.
The MMC also generates two external chip select signals, emulation chip select (ECS) and external chip
select (XCS).
3.4.2.1 Select Priority and Mode Considerations
Although internal resources such as control registers and on-chip memory have default addresses, each can
be relocated by changing the default values in control registers. Normally, I/O addresses, control registers,
Table 3-14. Program Page Index Register Bits
PIX5 PIX4 PIX3 PIX2 PIX1 PIX0 Program Space
Selected
000000 16K page 0
000001 16K page 1
000010 16K page 2
000011 16K page 3
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
111100 16K page 60
111101 16K page 61
111110 16K page 62
111111 16K page 63
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 123
Rev 01.24
vector spaces, expansion windows, and on-chip memory are mapped so that their address ranges do not
overlap. The MMC will make only one select signal active at any given time. This activation is based upon
the priority outlined in Table 3-15. If two or more blocks share the same address space, only the select
signal for the block with the highest priority will become active. An example of this is if the registers and
the RAM are mapped to the same space, the registers will have priority over the RAM and the portion of
RAM mapped in this shared space will not be accessible. The expansion windows have the lowest priority.
This means that registers, vectors, and on-chip memory are always visible to a program regardless of the
values in the page select registers.
In expanded modes, all address space not used by internal resources is by default external memory space.
The data registers and data direction registers for ports A and B are removed from the on-chip memory
map and become external accesses. If the EME bit in the MODE register (see MEBI block description
chapter) is set, the data and data direction registers for port E are also removed from the on-chip memory
map and become external accesses.
In special peripheral mode, the first 16 registers associated with bus expansion are removed from the on-
chip memory map (PORTA, PORTB, DDRA, DDRB, PORTE, DDRE, PEAR, MODE, PUCR, RDRIV,
and the EBI reserved registers).
In emulation modes, if the EMK bit in the MODE register (see MEBI block description chapter) is set, the
data and data direction registers for port K are removed from the on-chip memory map and become
external accesses.
3.4.2.2 Emulation Chip Select Signal
When the EMK bit in the MODE register (see MEBI block description chapter) is set, port K bit 7 is used
as an active-low emulation chip select signal, ECS. This signal is active when the system is in emulation
mode, the EMK bit is set and the FLASH or ROM space is being addressed subject to the conditions
outlined in Section 3.4.3.2, “Extended Address (XAB19:14) and ECS Signal Functionality.” When the
EMK bit is clear, this pin is used for general purpose I/O.
3.4.2.3 External Chip Select Signal
When the EMK bit in the MODE register (see MEBI block description chapter) is set, port K bit 6 is used
as an active-low external chip select signal, XCS. This signal is active only when the ECS signal described
above is not active and when the system is addressing the external address space. Accesses to
Table 3-15. Select Signal Priority
Priority Address Space
Highest BDM (internal to core) firmware or register space
... Internal register space
... RAM memory block
... EEPROM memory block
... On-chip FLASH or ROM
Lowest Remaining external space
Chapter 3 Module Mapping Control (MMCV4) Block Description
124 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
unimplemented locations within the register space or to locations that are removed from the map (i.e., ports
A and B in expanded modes) will not cause this signal to become active. When the EMK bit is clear, this
pin is used for general purpose I/O.
3.4.3 Memory Expansion
The HCS12 core architecture limits the physical address space available to 64K bytes. The program page
index register allows for integrating up to 1M byte of FLASH or ROM into the system by using the six
page index bits to page 16K byte blocks into the program page window located from 0x8000 to 0xBFFF
in the physical memory space. The paged memory space can consist of solely on-chip memory or a
combination of on-chip and off-chip memory. This partitioning is configured at system integration through
the use of the paging configuration switches (pag_sw1:pag_sw0) at the core boundary. The options
available to the integrator are as given in Table 3-16 (this table matches Table 3-12 but is repeated here for
easy reference).
Based upon the system configuration, the program page window will consider its access to be either
internal or external as defined in Table 3-17.
NOTE
The partitioning as defined in Table 3-17 applies only to the allocated
memory space and the actual on-chip memory sizes implemented in the
system may differ. Please refer to the device overview chapter for actual
sizes.
Table 3-16. Allocated Off-Chip Memory Options
pag_sw1:pag_sw0 Off-Chip Space On-Chip Space
00 876K bytes 128K bytes
01 768K bytes 256K bytes
10 512K bytes 512K bytes
11 0K byte 1M byte
Table 3-17. External/Internal Page Window Access
pag_sw1:pag_sw0 Partitioning PIX5:0 Value Page Window
Access
00 876K off-Chip,
128K on-Chip
0x0000–0x0037 External
0x0038–0x003F Internal
01 768K off-chip,
256K on-chip
0x0000–0x002F External
0x0030–0x003F Internal
10 512K off-chip,
512K on-chip
0x0000–0x001F External
0x0020–0x003F Internal
11 0K off-chip,
1M on-chip
N/A External
0x0000–0x003F Internal
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 125
Rev 01.24
The PPAGE register holds the page select value for the program page window. The value of the PPAGE
register can be manipulated by normal read and write (some devices don’t allow writes in some modes)
instructions as well as the CALL and RTC instructions.
Control registers, vector spaces, and a portion of on-chip memory are located in unpaged portions of the
64K byte physical address space. The stack and I/O addresses should also be in unpaged memory to make
them accessible from any page.
The starting address of a service routine must be located in unpaged memory because the 16-bit exception
vectors cannot point to addresses in paged memory. However, a service routine can call other routines that
are in paged memory. The upper 16K byte block of memory space (0xC000–0xFFFF) is unpaged. It is
recommended that all reset and interrupt vectors point to locations in this area.
3.4.3.1 CALL and Return from Call Instructions
CALL and RTC are uninterruptable instructions that automate page switching in the program expansion
window. CALL is similar to a JSR instruction, but the subroutine that is called can be located anywhere in
the normal 64K byte address space or on any page of program expansion memory. CALL calculates and
stacks a return address, stacks the current PPAGE value, and writes a new instruction-supplied value to
PPAGE. The PPAGE value controls which of the 64 possible pages is visible through the 16K byte
expansion window in the 64K byte memory map. Execution then begins at the address of the called
subroutine.
During the execution of a CALL instruction, the CPU:
• Writes the old PPAGE value into an internal temporary register and writes the new instruction-
supplied PPAGE value into the PPAGE register.
• Calculates the address of the next instruction after the CALL instruction (the return address), and
pushes this 16-bit value onto the stack.
• Pushes the old PPAGE value onto the stack.
• Calculates the effective address of the subroutine, refills the queue, and begins execution at the new
address on the selected page of the expansion window.
This sequence is uninterruptable; there is no need to inhibit interrupts during CALL execution. A CALL
can be performed from any address in memory to any other address.
The PPAGE value supplied by the instruction is part of the effective address. For all addressing mode
variations except indexed-indirect modes, the new page value is provided by an immediate operand in the
instruction. In indexed-indirect variations of CALL, a pointer specifies memory locations where the new
page value and the address of the called subroutine are stored. Using indirect addressing for both the new
page value and the address within the page allows values calculated at run time rather than immediate
values that must be known at the time of assembly.
The RTC instruction terminates subroutines invoked by a CALL instruction. RTC unstacks the PPAGE
value and the return address and refills the queue. Execution resumes with the next instruction after the
CALL.
Chapter 3 Module Mapping Control (MMCV4) Block Description
126 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
During the execution of an RTC instruction, the CPU:
• Pulls the old PPAGE value from the stack
• Pulls the 16-bit return address from the stack and loads it into the PC
• Writes the old PPAGE value into the PPAGE register
• Refills the queue and resumes execution at the return address
This sequence is uninterruptable; an RTC can be executed from anywhere in memory, even from a different
page of extended memory in the expansion window.
The CALL and RTC instructions behave like JSR and RTS, except they use more execution cycles.
Therefore, routinely substituting CALL/RTC for JSR/RTS is not recommended. JSR and RTS can be used
to access subroutines that are on the same page in expanded memory. However, a subroutine in expanded
memory that can be called from other pages must be terminated with an RTC. And the RTC unstacks a
PPAGE value. So any access to the subroutine, even from the same page, must use a CALL instruction so
that the correct PPAGE value is in the stack.
3.4.3.2 Extended Address (XAB19:14) and ECS Signal Functionality
If the EMK bit in the MODE register is set (see MEBI block description chapter) the PIX5:0 values will
be output on XAB19:14 respectively (port K bits 5:0) when the system is addressing within the physical
program page window address space (0x8000–0xBFFF) and is in an expanded mode. When addressing
anywhere else within the physical address space (outside of the paging space), the XAB19:14 signals will
be assigned a constant value based upon the physical address space selected. In addition, the active-low
emulation chip select signal, ECS, will likewise function based upon the assigned memory allocation. In
the cases of 48K byte and 64K byte allocated physical FLASH/ROM space, the operation of the ECS
signal will additionally depend upon the state of the ROMHM bit (see Section 3.3.2.4, “Miscellaneous
System Control Register (MISC)”) in the MISC register. Table 3-18,Table 3-19,Table 3-20, and Table 3-
21 summarize the functionality of these signals based upon the allocated memory configuration. Again,
this signal information is only available externally when the EMK bit is set and the system is in an
expanded mode.
Table 3-18. 0K Byte Physical FLASH/ROM Allocated
Address Space Page Window Access ROMHM ECS XAB19:14
0x0000–0x3FFF N/A N/A 1 0x3D
0x4000–0x7FFF N/A N/A 1 0x3E
0x8000–0xBFFF N/A N/A 0 PIX[5:0]
0xC000–0xFFFF N/A N/A 0 0x3F
Table 3-19. 16K Byte Physical FLASH/ROM Allocated
Address Space Page Window Access ROMHM ECS XAB19:14
0x0000–0x3FFF N/A N/A 1 0x3D
0x4000–0x7FFF N/A N/A 1 0x3E
0x8000–0xBFFF N/A N/A 1 PIX[5:0]
0xC000–0xFFFF N/A N/A 0 0x3F
Chapter 3 Module Mapping Control (MMCV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 127
Rev 01.24
Table 3-20. 48K Byte Physical FLASH/ROM Allocated
Address Space Page Window Access ROMHM ECS XAB19:14
0x0000–0x3FFF N/A N/A 1 0x3D
0x4000–0x7FFF N/A 0 0 0x3E
N/A 1 1
0x8000–0xBFFF External N/A 1 PIX[5:0]
Internal N/A 0
0xC000–0xFFFF N/A N/A 0 0x3F
Table 3-21. 64K Byte Physical FLASH/ROM Allocated
Address Space Page Window Access ROMHM ECS XAB19:14
0x0000–0x3FFF N/A 0 0 0x3D
N/A 1 1
0x4000–0x7FFF N/A 0 0 0x3E
N/A 1 1
0x8000–0xBFFF External N/A 1 PIX[5:0]
Internal N/A 0
0xC000–0xFFFF N/A N/A 0 0x3F
Chapter 3 Module Mapping Control (MMCV4) Block Description
128 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A graphical example of a memory paging for a system configured as 1M byte on-chip FLASH/ROM with
64K allocated physical space is given in Figure 3-12.
Figure 3-12. Memory Paging Example: 1M Byte On-Chip FLASH/ROM, 64K Allocation
These 16K FLASH/ROM pages accessible from 0x0000 to 0x7FFF if selected
by the ROMHM bit in the MISC register.
NORMAL
SINGLE CHIP
ONE 16K FLASH/ROM PAGE ACCESSIBLE AT A TIME
(SELECTED BY PPAGE = 0 TO 63)
0x0000
0x8000
0xFF00
0xFFFF
0x4000
0xC000
59
62
63
60 61 62 630123
61
16K FLASH
(UNPAGED)
16K FLASH
(UNPAGED)
16K FLASH
(PAGED)
16K FLASH
(UNPAGED)
VECTORS
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 129
Rev 01.24
Chapter 4
Multiplexed External Bus Interface (MEBIV3)
4.1 Introduction
This section describes the functionality of the multiplexed external bus interface (MEBI) sub-block of the
S12 core platform. The functionality of the module is closely coupled with the S12 CPU and the memory
map controller (MMC) sub-blocks.
Figure 4-1 is a block diagram of the MEBI. In Figure 4-1, the signals on the right hand side represent pins
that are accessible externally. On some chips, these may not all be bonded out.
The MEBI sub-block of the core serves to provide access and/or visibility to internal core data
manipulation operations including timing reference information at the external boundary of the core and/or
system. Depending upon the system operating mode and the state of bits within the control registers of the
MEBI, the internal 16-bit read and write data operations will be represented in 8-bit or 16-bit accesses
externally. Using control information from other blocks within the system, the MEBI will determine the
appropriate type of data access to be generated.
4.1.1 Features
The block name includes these distinctive features:
• External bus controller with four 8-bit ports A,B, E, and K
• Data and data direction registers for ports A, B, E, and K when used as general-purpose I/O
• Control register to enable/disable alternate functions on ports E and K
• Mode control register
• Control register to enable/disable pull resistors on ports A, B, E, and K
• Control register to enable/disable reduced output drive on ports A, B, E, and K
• Control register to configure external clock behavior
• Control register to configure IRQ pin operation
• Logic to capture and synchronize external interrupt pin inputs
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
130 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 4-1. MEBI Block Diagram
PE[7:2]/NOACC/
PE1/IRQ
PE0/XIRQ
BKGD/MODC/TAGHI
PK[7:0]/ECS/XCS/X[19:14]
PA[7:0]/A[15:8]/
D[15:8]/D[7:0]
Port KPort A
PB[7:0]/A[7:0]/
D[7:0]
Port BPort E
BKGD
REGS
EXT
BUS
I/F
CTL
Addr[19:0]
Data[15:0]
(Control)
Internal Bus
ECLK CTL
IRQ CTL
ADDR
ADDR
DATA
ADDR
DATA
PIPE CTL
CPU pipe info
IRQ interrupt
XIRQ interrupt
BDM tag info
IPIPE1/MODB/CLKTO
IPIPE0/MODA/
ECLK/
LSTRB/TAGLO
R/W
TAG CTL
Control signal(s)
Data signal (unidirectional)
Data bus (unidirectional)
Data bus (bidirectional)
Data signal (bidirectional)
mode
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 131
Rev 01.24
4.1.2 Modes of Operation
• Normal expanded wide mode
Ports A and B are configured as a 16-bit multiplexed address and data bus and port E provides bus
control and status signals. This mode allows 16-bit external memory and peripheral devices to be
interfaced to the system.
• Normal expanded narrow mode
Ports A and B are configured as a 16-bit address bus and port A is multiplexed with 8-bit data.
Port E provides bus control and status signals. This mode allows 8-bit external memory and
peripheral devices to be interfaced to the system.
• Normal single-chip mode
There is no external expansion bus in this mode. The processor program is executed from internal
memory. Ports A, B, K, and most of E are available as general-purpose I/O.
• Special single-chip mode
This mode is generally used for debugging single-chip operation, boot-strapping, or security
related operations. The active background mode is in control of CPU execution and BDM firmware
is waiting for additional serial commands through the BKGD pin. There is no external expansion
bus after reset in this mode.
• Emulation expanded wide mode
Developers use this mode for emulation systems in which the users target application is normal
expanded wide mode.
• Emulation expanded narrow mode
Developers use this mode for emulation systems in which the users target application is normal
expanded narrow mode.
• Special test mode
Ports A and B are configured as a 16-bit multiplexed address and data bus and port E provides bus
control and status signals. In special test mode, the write protection of many control bits is lifted
so that they can be thoroughly tested without needing to go through reset.
• Special peripheral mode
This mode is intended for Freescale Semiconductor factory testing of the system. The CPU is
inactive and an external (tester) bus master drives address, data, and bus control signals.
4.2 External Signal Description
In typical implementations, the MEBI sub-block of the core interfaces directly with external system pins.
Some pins may not be bonded out in all implementations.
Table 4-1 outlines the pin names and functions and gives a brief description of their operation reset state
of these pins and associated pull-ups or pull-downs is dependent on the mode of operation and on the
integration of this block at the chip level (chip dependent).
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
132 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
.Table 4-1. External System Pins Associated With MEBI
Pin Name Pin Functions Description
BKGD/MODC/
TAGHI
MODC At the rising edge on RESET, the state of this pin is registered into the MODC
bit to set the mode. (This pin always has an internal pullup.)
BKGD Pseudo open-drain communication pin for the single-wire background debug
mode. There is an internal pull-up resistor on this pin.
TAGHI When instruction tagging is on, a 0 at the falling edge of E tags the high half of
the instruction word being read into the instruction queue.
PA7/A15/D15/D7
thru
PA0/A8/D8/D0
PA7–PA0 General-purpose I/O pins, see PORTA and DDRA registers.
A15–A8 High-order address lines multiplexed during ECLK low. Outputs except in
special peripheral mode where they are inputs from an external tester system.
D15–D8 High-order bidirectional data lines multiplexed during ECLK high in expanded
wide modes, special peripheral mode, and visible internal accesses (IVIS = 1)
in emulation expanded narrow mode. Direction of data transfer is generally
indicated by R/W.
D15/D7
thru
D8/D0
Alternate high-order and low-order bytes of the bidirectional data lines
multiplexed during ECLK high in expanded narrow modes and narrow accesses
in wide modes. Direction of data transfer is generally indicated by R/W.
PB7/A7/D7
thru
PB0/A0/D0
PB7–PB0 General-purpose I/O pins, see PORTB and DDRB registers.
A7–A0 Low-order address lines multiplexed during ECLK low. Outputs except in
special peripheral mode where they are inputs from an external tester system.
D7–D0 Low-order bidirectional data lines multiplexed during ECLK high in expanded
wide modes, special peripheral mode, and visible internal accesses (with
IVIS = 1) in emulation expanded narrow mode. Direction of data transfer is
generally indicated by R/W.
PE7/NOACC PE7 General-purpose I/O pin, see PORTE and DDRE registers.
NOACC CPU No Access output. Indicates whether the current cycle is a free cycle. Only
available in expanded modes.
PE6/IPIPE1/
MODB/CLKTO
MODB At the rising edge of RESET, the state of this pin is registered into the MODB
bit to set the mode.
PE6 General-purpose I/O pin, see PORTE and DDRE registers.
IPIPE1 Instruction pipe status bit 1, enabled by PIPOE bit in PEAR.
CLKTO System clock test output. Only available in special modes. PIPOE = 1 overrides
this function. The enable for this function is in the clock module.
PE5/IPIPE0/MODA MODA At the rising edge on RESET, the state of this pin is registered into the MODA
bit to set the mode.
PE5 General-purpose I/O pin, see PORTE and DDRE registers.
IPIPE0 Instruction pipe status bit 0, enabled by PIPOE bit in PEAR.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 133
Rev 01.24
Detailed descriptions of these pins can be found in the device overview chapter.
4.3 Memory Map and Register Definition
A summary of the registers associated with the MEBI sub-block is shown in Table 4-2. Detailed
descriptions of the registers and bits are given in the subsections that follow. On most chips the registers
are mappable. Therefore, the upper bits may not be all 0s as shown in the table and descriptions.
PE4/ECLK PE4 General-purpose I/O pin, see PORTE and DDRE registers.
ECLK Bus timing reference clock, can operate as a free-running clock at the system
clock rate or to produce one low-high clock per visible access, with the high
period stretched for slow accesses. ECLK is controlled by the NECLK bit in
PEAR, the IVIS bit in MODE, and the ESTR bit in EBICTL.
PE3/LSTRB/ TAGLO PE3 General-purpose I/O pin, see PORTE and DDRE registers.
LSTRB Low strobe bar, 0 indicates valid data on D7–D0.
SZ8 In special peripheral mode, this pin is an input indicating the size of the data
transfer (0 = 16-bit; 1 = 8-bit).
TAGLO In expanded wide mode or emulation narrow modes, when instruction tagging
is on and low strobe is enabled, a 0 at the falling edge of E tags the low half of
the instruction word being read into the instruction queue.
PE2/R/W PE2 General-purpose I/O pin, see PORTE and DDRE registers.
R/W Read/write, indicates the direction of internal data transfers. This is an output
except in special peripheral mode where it is an input.
PE1/IRQ PE1 General-purpose input-only pin, can be read even if IRQ enabled.
IRQ Maskable interrupt request, can be level sensitive or edge sensitive.
PE0/XIRQ PE0 General-purpose input-only pin.
XIRQ Non-maskable interrupt input.
PK7/ECS PK7 General-purpose I/O pin, see PORTK and DDRK registers.
ECS Emulation chip select
PK6/XCS PK6 General-purpose I/O pin, see PORTK and DDRK registers.
XCS External data chip select
PK5/X19
thru
PK0/X14
PK5–PK0 General-purpose I/O pins, see PORTK and DDRK registers.
X19–X14 Memory expansion addresses
Table 4-1. External System Pins Associated With MEBI (continued)
Pin Name Pin Functions Description
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
134 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
4.3.1 Module Memory Map
4.3.2 Register Descriptions
4.3.2.1 Port A Data Register (PORTA)
Table 4-2. MEBI Memory Map
Address
Offset Use Access
0x0000 Port A Data Register (PORTA) R/W
0x0001 Port B Data Register (PORTB) R/W
0x0002 Data Direction Register A (DDRA) R/W
0x0003 Data Direction Register B (DDRB) R/W
0x0004 Reserved R
0x0005 Reserved R
0x0006 Reserved R
0x0007 Reserved R
0x0008 Port E Data Register (PORTE) R/W
0x0009 Data Direction Register E (DDRE) R/W
0x000A Port E Assignment Register (PEAR) R/W
0x000B Mode Register (MODE) R/W
0x000C Pull Control Register (PUCR) R/W
0x000D Reduced Drive Register (RDRIV) R/W
0x000E External Bus Interface Control Register (EBICTL) R/W
0x000F Reserved R
0x001E IRQ Control Register (IRQCR) R/W
0x00032 Port K Data Register (PORTK) R/W
0x00033 Data Direction Register K (DDRK) R/W
Module Base + 0x0000
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 6 5 4 3 2 1 Bit 0
W
Reset 0 0 0 0 0 0 0 0
Single Chip PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0
Expanded Wide,
Emulation Narrow with
IVIS, and Peripheral
AB/DB15 AB/DB14 AB/DB13 AB/DB12 AB/DB11 AB/DB10 AB/DB9 AB/DB8
Expanded Narrow AB15 and
DB15/DB7
AB14 and
DB14/DB6
AB13 and
DB13/DB5
AB12 and
DB12/DB4
AB11 and
DB11/DB3
AB10 and
DB10/DB2
AB9 and
DB9/DB1
AB8 and
DB8/DB0
Figure 4-2. Port A Data Register (PORTA)
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 135
Rev 01.24
Read: Anytime when register is in the map
Write: Anytime when register is in the map
Port A bits 7 through 0 are associated with address lines A15 through A8 respectively and data lines
D15/D7 through D8/D0 respectively. When this port is not used for external addresses such as in single-
chip mode, these pins can be used as general-purpose I/O. Data direction register A (DDRA) determines
the primary direction of each pin. DDRA also determines the source of data for a read of PORTA.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
NOTE
To ensure that you read the value present on the PORTA pins, always wait
at least one cycle after writing to the DDRA register before reading from the
PORTA register.
4.3.2.2 Port B Data Register (PORTB)
Read: Anytime when register is in the map
Write: Anytime when register is in the map
Port B bits 7 through 0 are associated with address lines A7 through A0 respectively and data lines D7
through D0 respectively. When this port is not used for external addresses, such as in single-chip mode,
these pins can be used as general-purpose I/O. Data direction register B (DDRB) determines the primary
direction of each pin. DDRB also determines the source of data for a read of PORTB.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
NOTE
To ensure that you read the value present on the PORTB pins, always wait
at least one cycle after writing to the DDRB register before reading from the
PORTB register.
Module Base + 0x0001
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 6 5 4 3 2 1 Bit 0
W
Reset 0 0 0 0 0 0 0 0
Single Chip PB7 PB6 PB5 PB4 PB3 PB2 PB1 PB0
Expanded Wide,
Emulation Narrow with
IVIS, and Peripheral
AB/DB7 AB/DB6 AB/DB5 AB/DB4 AB/DB3 AB/DB2 AB/DB1 AB/DB0
Expanded Narrow AB7 AB6 AB5 AB4 AB3 AB2 AB1 AB0
Figure 4-3. Port A Data Register (PORTB)
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
136 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
4.3.2.3 Data Direction Register A (DDRA)
Read: Anytime when register is in the map
Write: Anytime when register is in the map
This register controls the data direction for port A. When port A is operating as a general-purpose I/O port,
DDRA determines the primary direction for each port A pin. A 1 causes the associated port pin to be an
output and a 0 causes the associated pin to be a high-impedance input. The value in a DDR bit also affects
the source of data for reads of the corresponding PORTA register. If the DDR bit is 0 (input) the buffered
pin input state is read. If the DDR bit is 1 (output) the associated port data register bit state is read.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally. It is reset to 0x00 so the DDR does not override the three-state control
signals.
Module Base + 0x0002
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 4-4. Data Direction Register A (DDRA)
Table 4-3. DDRA Field Descriptions
Field Description
7:0
DDRA
Data Direction Port A
0 Configure the corresponding I/O pin as an input
1 Configure the corresponding I/O pin as an output
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 137
Rev 01.24
4.3.2.4 Data Direction Register B (DDRB)
Read: Anytime when register is in the map
Write: Anytime when register is in the map
This register controls the data direction for port B. When port B is operating as a general-purpose I/O port,
DDRB determines the primary direction for each port B pin. A 1 causes the associated port pin to be an
output and a 0 causes the associated pin to be a high-impedance input. The value in a DDR bit also affects
the source of data for reads of the corresponding PORTB register. If the DDR bit is 0 (input) the buffered
pin input state is read. If the DDR bit is 1 (output) the associated port data register bit state is read.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally. It is reset to 0x00 so the DDR does not override the three-state control
signals.
Module Base + 0x0003
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 4-5. Data Direction Register B (DDRB)
Table 4-4. DDRB Field Descriptions
Field Description
7:0
DDRB
Data Direction Port B
0 Configure the corresponding I/O pin as an input
1 Configure the corresponding I/O pin as an output
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
138 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
4.3.2.5 Reserved Registers
Module Base + 0x0004
Starting address location affected by INITRG register setting.
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 4-6. Reserved Register
Module Base + 0x0005
Starting address location affected by INITRG register setting.
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 4-7. Reserved Register
Module Base + 0x0006
Starting address location affected by INITRG register setting.
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 4-8. Reserved Register
Module Base + 0x0007
Starting address location affected by INITRG register setting.
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 4-9. Reserved Register
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 139
Rev 01.24
These register locations are not used (reserved). All unused registers and bits in this block return logic 0s
when read. Writes to these registers have no effect.
These registers are not in the on-chip map in special peripheral mode.
4.3.2.6 Port E Data Register (PORTE)
Read: Anytime when register is in the map
Write: Anytime when register is in the map
Port E is associated with external bus control signals and interrupt inputs. These include mode select
(MODB/IPIPE1, MODA/IPIPE0), E clock, size (LSTRB/TAGLO), read/write (R/W), IRQ, and XIRQ.
When not used for one of these specific functions, port E pins 7:2 can be used as general-purpose I/O and
pins 1:0 can be used as general-purpose input. The port E assignment register (PEAR) selects the function
of each pin and DDRE determines whether each pin is an input or output when it is configured to be
general-purpose I/O. DDRE also determines the source of data for a read of PORTE.
Some of these pins have software selectable pull resistors. IRQ and XIRQ can only be pulled up whereas
the polarity of the PE7, PE4, PE3, and PE2 pull resistors are determined by chip integration. Please refer
to the device overview chapter (Signal Property Summary) to determine the polarity of these resistors.
A single control bit enables the pull devices for all of these pins when they are configured as inputs.
This register is not in the on-chip map in special peripheral mode or in expanded modes when the EME
bit is set. Therefore, these accesses will be echoed externally.
NOTE
It is unwise to write PORTE and DDRE as a word access. If you are
changing port E pins from being inputs to outputs, the data may have extra
transitions during the write. It is best to initialize PORTE before enabling as
outputs.
Module Base + 0x0008
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 65432
Bit 1 Bit 0
W
Reset 000000uu
Alternate
Pin Function NOACC
MODB
or IPIPE1
or CLKTO
MODA
or IPIPE0 ECLK LSTRB
or TAGLO R/W IRQ XIRQ
= Unimplemented or Reserved u = Unaffected by reset
Figure 4-10. Port E Data Register (PORTE)
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
140 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
NOTE
To ensure that you read the value present on the PORTE pins, always wait
at least one cycle after writing to the DDRE register before reading from the
PORTE register.
4.3.2.7 Data Direction Register E (DDRE)
Read: Anytime when register is in the map
Write: Anytime when register is in the map
Data direction register E is associated with port E. For bits in port E that are configured as general-purpose
I/O lines, DDRE determines the primary direction of each of these pins. A 1 causes the associated bit to
be an output and a 0 causes the associated bit to be an input. Port E bit 1 (associated with IRQ) and bit 0
(associated with XIRQ) cannot be configured as outputs. Port E, bits 1 and 0, can be read regardless of
whether the alternate interrupt function is enabled. The value in a DDR bit also affects the source of data
for reads of the corresponding PORTE register. If the DDR bit is 0 (input) the buffered pin input state is
read. If the DDR bit is 1 (output) the associated port data register bit state is read.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally. Also, it is not in the map in expanded modes while the EME control bit
is set.
Module Base + 0x0009
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 6 5 4 3 Bit 2
00
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 4-11. Data Direction Register E (DDRE)
Table 4-5. DDRE Field Descriptions
Field Description
7:2
DDRE
Data Direction Port E
0 Configure the corresponding I/O pin as an input
1 Configure the corresponding I/O pin as an output
Note: It is unwise to write PORTE and DDRE as a word access. If you are changing port E pins from inputs to
outputs, the data may have extra transitions during the write. It is best to initialize PORTE before enabling
as outputs.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 141
Rev 01.24
4.3.2.8 Port E Assignment Register (PEAR)
Read: Anytime (provided this register is in the map).
Write: Each bit has specific write conditions. Please refer to the descriptions of each bit on the following
pages.
Port E serves as general-purpose I/O or as system and bus control signals. The PEAR register is used to
choose between the general-purpose I/O function and the alternate control functions. When an alternate
control function is selected, the associated DDRE bits are overridden.
The reset condition of this register depends on the mode of operation because bus control signals are
needed immediately after reset in some modes. In normal single-chip mode, no external bus control signals
are needed so all of port E is configured for general-purpose I/O. In normal expanded modes, only the E
clock is configured for its alternate bus control function and the other bits of port E are configured for
general-purpose I/O. As the reset vector is located in external memory, the E clock is required for this
access. R/W is only needed by the system when there are external writable resources. If the normal
expanded system needs any other bus control signals, PEAR would need to be written before any access
that needed the additional signals. In special test and emulation modes, IPIPE1, IPIPE0, E, LSTRB, and
R/W are configured out of reset as bus control signals.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
Module Base + 0x000A
Starting address location affected by INITRG register setting.
76543210
R
NOACCE
0
PIPOE NECLK LSTRE RDWE
00
W
Reset
Special Single Chip 0 0 0 0 0 0 0 0
Special Test 0 0 1 0 1 1 0 0
Peripheral 0 0 0 0 0 0 0 0
Emulation Expanded
Narrow 10101100
Emulation Expanded
Wide 10101100
Normal Single Chip 0 0 0 1 0 0 0 0
Normal Expanded
Narrow 00000000
Normal Expanded Wide 0 0 0 0 0 0 0 0
= Unimplemented or Reserved
Figure 4-12. Port E Assignment Register (PEAR)
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
142 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 4-6. PEAR Field Descriptions
Field Description
7
NOACCE
CPU No Access Output Enable
Normal: write once
Emulation: write never
Special: write anytime
1 The associated pin (port E, bit 7) is general-purpose I/O.
0 The associated pin (port E, bit 7) is output and indicates whether the cycle is a CPU free cycle.
This bit has no effect in single-chip or special peripheral modes.
5
PIPOE
Pipe Status Signal Output Enable
Normal: write once
Emulation: write never
Special: write anytime.
0 The associated pins (port E, bits 6:5) are general-purpose I/O.
1 The associated pins (port E, bits 6:5) are outputs and indicate the state of the instruction queue
This bit has no effect in single-chip or special peripheral modes.
4
NECLK
No External E Clock
Normal and special: write anytime
Emulation: write never
0 The associated pin (port E, bit 4) is the external E clock pin. External E clock is free-running if ESTR = 0
1 The associated pin (port E, bit 4) is a general-purpose I/O pin.
External E clock is available as an output in all modes.
3
LSTRE
Low Strobe (LSTRB) Enable
Normal: write once
Emulation: write never
Special: write anytime.
0 The associated pin (port E, bit 3) is a general-purpose I/O pin.
1 The associated pin (port E, bit 3) is configured as the LSTRB bus control output. If BDM tagging is enabled,
TAGLO is multiplexed in on the rising edge of ECLK and LSTRB is driven out on the falling edge of ECLK.
This bit has no effect in single-chip, peripheral, or normal expanded narrow modes.
Note: LSTRB is used during external writes. After reset in normal expanded mode, LSTRB is disabled to provide
an extra I/O pin. If LSTRB is needed, it should be enabled before any external writes. External reads do
not normally need LSTRB because all 16 data bits can be driven even if the system only needs 8 bits of
data.
2
RDWE
Read/Write Enable
Normal: write once
Emulation: write never
Special: write anytime
0 The associated pin (port E, bit 2) is a general-purpose I/O pin.
1 The associated pin (port E, bit 2) is configured as the R/W pin
This bit has no effect in single-chip or special peripheral modes.
Note: R/W is used for external writes. After reset in normal expanded mode, R/W is disabled to provide an extra
I/O pin. If R/W is needed it should be enabled before any external writes.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 143
Rev 01.24
4.3.2.9 Mode Register (MODE)
Read: Anytime (provided this register is in the map).
Write: Each bit has specific write conditions. Please refer to the descriptions of each bit on the following
pages.
The MODE register is used to establish the operating mode and other miscellaneous functions (i.e.,
internal visibility and emulation of port E and K).
In special peripheral mode, this register is not accessible but it is reset as shown to system configuration
features. Changes to bits in the MODE register are delayed one cycle after the write.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
Module Base + 0x000B
Starting address location affected by INITRG register setting.
76543210
R
MODC MODB MODA
0
IVIS
0
EMK EME
W
Reset
Special Single Chip 0 0 0 0 0 0 0 0
Emulation Expanded
Narrow 00101011
Special Test 0 1 0 0 1 0 0 0
Emulation Expanded
Wide 01101011
Normal Single Chip 1 0 0 0 0 0 0 0
Normal Expanded
Narrow 10100000
Peripheral 1 1 0 0 0 0 0 0
Normal Expanded Wide 1 1 1 0 0 0 0 0
= Unimplemented or Reserved
Figure 4-13. Mode Register (MODE)
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
144 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 4-7. MODE Field Descriptions
Field Description
7:5
MOD[C:A]
Mode Select Bits — These bits indicate the current operating mode.
If MODA = 1, then MODC, MODB, and MODA are write never.
If MODC = MODA = 0, then MODC, MODB, and MODA are writable with the exception that you cannot change
to or from special peripheral mode
If MODC = 1, MODB = 0, and MODA = 0, then MODC is write never. MODB and MODA are write once, except
that you cannot change to special peripheral mode. From normal single-chip, only normal expanded narrow and
normal expanded wide modes are available.
See Table 4-8 and Table 4-16.
3
IVIS
Internal Visibility (for both read and write accesses) — This bit determines whether internal accesses
generate a bus cycle that is visible on the external bus.
Normal: write once
Emulation: write never
Special: write anytime
0 No visibility of internal bus operations on external bus.
1 Internal bus operations are visible on external bus.
1
EMK
Emulate Port K
Normal: write once
Emulation: write never
Special: write anytime
0 PORTK and DDRK are in the memory map so port K can be used for general-purpose I/O.
1 If in any expanded mode, PORTK and DDRK are removed from the memory map.
In single-chip modes, PORTK and DDRK are always in the map regardless of the state of this bit.
In special peripheral mode, PORTK and DDRK are never in the map regardless of the state of this bit.
0
EME
Emulate Port E
Normal and Emulation: write never
Special: write anytime
0 PORTE and DDRE are in the memory map so port E can be used for general-purpose I/O.
1 If in any expanded mode or special peripheral mode, PORTE and DDRE are removed from the memory map.
Removing the registers from the map allows the user to emulate the function of these registers externally.
In single-chip modes, PORTE and DDRE are always in the map regardless of the state of this bit.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 145
Rev 01.24
4.3.2.10 Pull Control Register (PUCR)
Read: Anytime (provided this register is in the map).
Write: Anytime (provided this register is in the map).
This register is used to select pull resistors for the pins associated with the core ports. Pull resistors are
assigned on a per-port basis and apply to any pin in the corresponding port that is currently configured as
an input. The polarity of these pull resistors is determined by chip integration. Please refer to the device
overview chapter to determine the polarity of these resistors.
Table 4-8. MODC, MODB, and MODA Write Capability(1)
1. No writes to the MOD bits are allowed while operating in a secure mode. For more details, refer to the device over-
view chapter.
MODC MODB MODA Mode MODx Write Capability
0 0 0 Special single chip MODC, MODB, and MODA
write anytime but not to 110(2)
2. If you are in a special single-chip or special test mode and you write to this register, changing to normal single-chip
mode, then one allowed write to this register remains. If you write to normal expanded or emulation mode, then no
writes remain.
0 0 1 Emulation narrow No write
0 1 0 Special test MODC, MODB, and MODA
write anytime but not to 110(2)
0 1 1 Emulation wide No write
1 0 0 Normal single chip MODC write never,
MODB and MODA write once
but not to 110
1 0 1 Normal expanded narrow No write
1 1 0 Special peripheral No write
1 1 1 Normal expanded wide No write
Module Base + 0x000C
Starting address location affected by INITRG register setting.
76543210
R
PUPKE
00
PUPEE
00
PUPBE PUPAE
W
Reset110010000
NOTES:
1. The default value of this parameter is shown. Please refer to the device overview chapter to deter-
mine the actual reset state of this register.
= Unimplemented or Reserved
Figure 4-14. Pull Control Register (PUCR)
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
146 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
NOTE
These bits have no effect when the associated pin(s) are outputs. (The pull
resistors are inactive.)
4.3.2.11 Reduced Drive Register (RDRIV)
Read: Anytime (provided this register is in the map)
Write: Anytime (provided this register is in the map)
This register is used to select reduced drive for the pins associated with the core ports. This gives reduced
power consumption and reduced RFI with a slight increase in transition time (depending on loading). This
feature would be used on ports which have a light loading. The reduced drive function is independent of
which function is being used on a particular port.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
Table 4-9. PUCR Field Descriptions
Field Description
7
PUPKE
Pull resistors Port K Enable
0 Port K pull resistors are disabled.
1 Enable pull resistors for port K input pins.
4
PUPEE
Pull resistors Port E Enable
0 Port E pull resistors on bits 7, 4:0 are disabled.
1 Enable pull resistors for port E input pins bits 7, 4:0.
Note: Pins 5 and 6 of port E have pull resistors which are only enabled during reset. This bit has no effect on
these pins.
1
PUPBE
Pull resistors Port B Enable
0 Port B pull resistors are disabled.
1 Enable pull resistors for all port B input pins.
0
PUPAE
Pull resistors Port A Enable
0 Port A pull resistors are disabled.
1 Enable pull resistors for all port A input pins.
Module Base + 0x000D
Starting address location affected by INITRG register setting.
76543210
R
RDRK
00
RDPE
00
RDPB RDPA
W
Reset 00000000
= Unimplemented or Reserved
Figure 4-15. Reduced Drive Register (RDRIV)
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 147
Rev 01.24
4.3.2.12 External Bus Interface Control Register (EBICTL)
Read: Anytime (provided this register is in the map)
Write: Refer to individual bit descriptions below
The EBICTL register is used to control miscellaneous functions (i.e., stretching of external E clock).
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
Table 4-10. RDRIV Field Descriptions
Field Description
7
RDRK
Reduced Drive of Port K
0 All port K output pins have full drive enabled.
1 All port K output pins have reduced drive enabled.
4
RDPE
Reduced Drive of Port E
0 All port E output pins have full drive enabled.
1 All port E output pins have reduced drive enabled.
1
RDPB
Reduced Drive of Port B
0 All port B output pins have full drive enabled.
1 All port B output pins have reduced drive enabled.
0
RDPA
Reduced Drive of Ports A
0 All port A output pins have full drive enabled.
1 All port A output pins have reduced drive enabled.
Module Base + 0x000E
Starting address location affected by INITRG register setting.
76543210
R0000000
ESTR
W
Reset:
Peripheral
All other modes
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
= Unimplemented or Reserved
Figure 4-16. External Bus Interface Control Register (EBICTL)
Table 4-11. EBICTL Field Descriptions
Field Description
0
ESTR
E Clock Stretches — This control bit determines whether the E clock behaves as a simple free-running clock or
as a bus control signal that is active only for external bus cycles.
Normal and Emulation: write once
Special: write anytime
0 E never stretches (always free running).
1 E stretches high during stretched external accesses and remains low during non-visible internal accesses.
This bit has no effect in single-chip modes.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
148 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
4.3.2.13 Reserved Register
This register location is not used (reserved). All bits in this register return logic 0s when read. Writes to
this register have no effect.
This register is not in the on-chip memory map in expanded and special peripheral modes. Therefore, these
accesses will be echoed externally.
4.3.2.14 IRQ Control Register (IRQCR)
Read: See individual bit descriptions below
Write: See individual bit descriptions below
Module Base + 0x000F
Starting address location affected by INITRG register setting.
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 4-17. Reserved Register
Module Base + 0x001E
Starting address location affected by INITRG register setting.
76543210
R
IRQE IRQEN
000000
W
Reset 01000000
= Unimplemented or Reserved
Figure 4-18. IRQ Control Register (IRQCR)
Table 4-12. IRQCR Field Descriptions
Field Description
7
IRQE
IRQ Select Edge Sensitive Only
Special modes: read or write anytime
Normal and Emulation modes: read anytime, write once
0 IRQ configured for low level recognition.
1 IRQ configured to respond only to falling edges. Falling edges on the IRQ pin will be detected anytime
IRQE = 1 and will be cleared only upon a reset or the servicing of the IRQ interrupt.
6
IRQEN
External IRQ Enable
Normal, emulation, and special modes: read or write anytime
0 External IRQ pin is disconnected from interrupt logic.
1 External IRQ pin is connected to interrupt logic.
Note: When IRQEN = 0, the edge detect latch is disabled.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 149
Rev 01.24
4.3.2.15 Port K Data Register (PORTK)
Read: Anytime
Write: Anytime
This port is associated with the internal memory expansion emulation pins. When the port is not enabled
to emulate the internal memory expansion, the port pins are used as general-purpose I/O. When port K is
operating as a general-purpose I/O port, DDRK determines the primary direction for each port K pin. A 1
causes the associated port pin to be an output and a 0 causes the associated pin to be a high-impedance
input. The value in a DDR bit also affects the source of data for reads of the corresponding PORTK register.
If the DDR bit is 0 (input) the buffered pin input is read. If the DDR bit is 1 (output) the output of the port
data register is read.
This register is not in the map in peripheral or expanded modes while the EMK control bit in MODE
register is set. Therefore, these accesses will be echoed externally.
When inputs, these pins can be selected to be high impedance or pulled up, based upon the state of the
PUPKE bit in the PUCR register.
Module Base + 0x0032
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 654321Bit 0
W
Reset 00000000
Alternate
Pin Function ECS XCS XAB19 XAB18 XAB17 XAB16 XAB15 XAB14
Figure 4-19. Port K Data Register (PORTK)
Table 4-13. PORTK Field Descriptions
Field Description
7
Port K, Bit 7
Port K, Bit 7 — This bit is used as an emulation chip select signal for the emulation of the internal memory
expansion, or as general-purpose I/O, depending upon the state of the EMK bit in the MODE register. While
this bit is used as a chip select, the external bit will return to its de-asserted state (VDD) for approximately 1/4
cycle just after the negative edge of ECLK, unless the external access is stretched and ECLK is free-running
(ESTR bit in EBICTL = 0). See the MMC block description chapter for additional details on when this signal
will be active.
6
Port K, Bit 6
Port K, Bit 6 — This bit is used as an external chip select signal for most external accesses that are not
selected by ECS (see the MMC block description chapter for more details), depending upon the state the of
the EMK bit in the MODE register. While this bit is used as a chip select, the external pin will return to its de-
asserted state (VDD) for approximately 1/4 cycle just after the negative edge of ECLK, unless the external
access is stretched and ECLK is free-running (ESTR bit in EBICTL = 0).
5:0
Port K, Bits 5:0
Port K, Bits 5:0 — These six bits are used to determine which FLASH/ROM or external memory array page
is being accessed. They can be viewed as expanded addresses XAB19–XAB14 of the 20-bit address used to
access up to1M byte internal FLASH/ROM or external memory array. Alternatively, these bits can be used for
general-purpose I/O depending upon the state of the EMK bit in the MODE register.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
150 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
4.3.2.16 Port K Data Direction Register (DDRK)
Read: Anytime
Write: Anytime
This register determines the primary direction for each port K pin configured as general-purpose I/O. This
register is not in the map in peripheral or expanded modes while the EMK control bit in MODE register is
set. Therefore, these accesses will be echoed externally.
4.4 Functional Description
4.4.1 Detecting Access Type from External Signals
The external signals LSTRB, R/W, and AB0 indicate the type of bus access that is taking place. Accesses
to the internal RAM module are the only type of access that would produce LSTRB = AB0 = 1, because
the internal RAM is specifically designed to allow misaligned 16-bit accesses in a single cycle. In these
cases the data for the address that was accessed is on the low half of the data bus and the data for
address + 1 is on the high half of the data bus. This is summarized in Table 4-15.
Module Base + 0x0033
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 654321Bit 0
W
Reset 00000000
Figure 4-20. Port K Data Direction Register (DDRK)
Table 4-14. EBICTL Field Descriptions
Field Description
7:0
DDRK
Data Direction Port K Bits
0 Associated pin is a high-impedance input
1 Associated pin is an output
Note: It is unwise to write PORTK and DDRK as a word access. If you are changing port K pins from inputs to
outputs, the data may have extra transitions during the write. It is best to initialize PORTK before enabling
as outputs.
Note: To ensure that you read the correct value from the PORTK pins, always wait at least one cycle after writing
to the DDRK register before reading from the PORTK register.
Table 4-15. Access Type vs. Bus Control Pins
LSTRB AB0 R/W Type of Access
1 0 1 8-bit read of an even address
0 1 1 8-bit read of an odd address
1 0 0 8-bit write of an even address
0 1 0 8-bit write of an odd address
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 151
Rev 01.24
4.4.2 Stretched Bus Cycles
In order to allow fast internal bus cycles to coexist in a system with slower external memory resources, the
HCS12 supports the concept of stretched bus cycles (module timing reference clocks for timers and baud
rate generators are not affected by this stretching). Control bits in the MISC register in the MMC sub-block
of the core specify the amount of stretch (0, 1, 2, or 3 periods of the internal bus-rate clock). While
stretching, the CPU state machines are all held in their current state. At this point in the CPU bus cycle,
write data would already be driven onto the data bus so the length of time write data is valid is extended
in the case of a stretched bus cycle. Read data would not be captured by the system until the E clock falling
edge. In the case of a stretched bus cycle, read data is not required until the specified setup time before the
falling edge of the stretched E clock. The chip selects, and R/W signals remain valid during the period of
stretching (throughout the stretched E high time).
NOTE
The address portion of the bus cycle is not stretched.
4.4.3 Modes of Operation
The operating mode out of reset is determined by the states of the MODC, MODB, and MODA pins during
reset (Table 4-16). The MODC, MODB, and MODA bits in the MODE register show the current operating
mode and provide limited mode switching during operation. The states of the MODC, MODB, and MODA
pins are latched into these bits on the rising edge of the reset signal.
0 0 1 16-bit read of an even address
1 1 1 16-bit read of an odd address
(low/high data swapped)
0 0 0 16-bit write to an even address
1 1 0 16-bit write to an odd address
(low/high data swapped)
Table 4-16. Mode Selection
MODC MODB MODA Mode Description
0 0 0 Special Single Chip, BDM allowed and ACTIVE. BDM is allowed in all
other modes but a serial command is required to make BDM active.
0 0 1 Emulation Expanded Narrow, BDM allowed
0 1 0 Special Test (Expanded Wide), BDM allowed
0 1 1 Emulation Expanded Wide, BDM allowed
1 0 0 Normal Single Chip, BDM allowed
1 0 1 Normal Expanded Narrow, BDM allowed
1 1 0 Peripheral; BDM allowed but bus operations would cause bus conflicts
(must not be used)
1 1 1 Normal Expanded Wide, BDM allowed
Table 4-15. Access Type vs. Bus Control Pins
LSTRB AB0 R/W Type of Access
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
152 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
There are two basic types of operating modes:
1. Normal modes: Some registers and bits are protected against accidental changes.
2. Special modes: Allow greater access to protected control registers and bits for special purposes
such as testing.
A system development and debug feature, background debug mode (BDM), is available in all modes. In
special single-chip mode, BDM is active immediately after reset.
Some aspects of Port E are not mode dependent. Bit 1 of Port E is a general purpose input or the IRQ
interrupt input. IRQ can be enabled by bits in the CPU’s condition codes register but it is inhibited at reset
so this pin is initially configured as a simple input with a pull-up. Bit 0 of Port E is a general purpose input
or the XIRQ interrupt input. XIRQ can be enabled by bits in the CPU’s condition codes register but it is
inhibited at reset so this pin is initially configured as a simple input with a pull-up. The ESTR bit in the
EBICTL register is set to one by reset in any user mode. This assures that the reset vector can be fetched
even if it is located in an external slow memory device. The PE6/MODB/IPIPE1 and PE5/MODA/IPIPE0
pins act as high-impedance mode select inputs during reset.
The following paragraphs discuss the default bus setup and describe which aspects of the bus can be
changed after reset on a per mode basis.
4.4.3.1 Normal Operating Modes
These modes provide three operating configurations. Background debug is available in all three modes, but
must first be enabled for some operations by means of a BDM background command, then activated.
4.4.3.1.1 Normal Single-Chip Mode
There is no external expansion bus in this mode. All pins of Ports A, B and E are configured as general
purpose I/O pins Port E bits 1 and 0 are available as general purpose input only pins with internal pull
resistors enabled. All other pins of Port E are bidirectional I/O pins that are initially configured as high-
impedance inputs with internal pull resistors enabled. Ports A and B are configured as high-impedance
inputs with their internal pull resistors disabled.
The pins associated with Port E bits 6, 5, 3, and 2 cannot be configured for their alternate functions IPIPE1,
IPIPE0, LSTRB, and R/W while the MCU is in single chip modes. In single chip modes, the associated
control bits PIPOE, LSTRE, and RDWE are reset to zero. Writing the opposite state into them in single
chip mode does not change the operation of the associated Port E pins.
In normal single chip mode, the MODE register is writable one time. This allows a user program to change
the bus mode to narrow or wide expanded mode and/or turn on visibility of internal accesses.
Port E, bit 4 can be configured for a free-running E clock output by clearing NECLK=0. Typically the only
use for an E clock output while the MCU is in single chip modes would be to get a constant speed clock
for use in the external application system.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 153
Rev 01.24
4.4.3.1.2 Normal Expanded Wide Mode
In expanded wide modes, Ports A and B are configured as a 16-bit multiplexed address and data bus and
Port E bit 4 is configured as the E clock output signal. These signals allow external memory and peripheral
devices to be interfaced to the MCU.
Port E pins other than PE4/ECLK are configured as general purpose I/O pins (initially high-impedance
inputs with internal pull resistors enabled). Control bits PIPOE, NECLK, LSTRE, and RDWE in the
PEAR register can be used to configure Port E pins to act as bus control outputs instead of general purpose
I/O pins.
It is possible to enable the pipe status signals on Port E bits 6 and 5 by setting the PIPOE bit in PEAR, but
it would be unusual to do so in this mode. Development systems where pipe status signals are monitored
would typically use the special variation of this mode.
The Port E bit 2 pin can be reconfigured as the R/W bus control signal by writing “1” to the RDWE bit in
PEAR. If the expanded system includes external devices that can be written, such as RAM, the RDWE bit
would need to be set before any attempt to write to an external location. If there are no writable resources
in the external system, PE2 can be left as a general purpose I/O pin.
The Port E bit 3 pin can be reconfigured as the LSTRB bus control signal by writing “1” to the LSTRE bit
in PEAR. The default condition of this pin is a general purpose input because the LSTRB function is not
needed in all expanded wide applications.
The Port E bit 4 pin is initially configured as ECLK output with stretch. The E clock output function
depends upon the settings of the NECLK bit in the PEAR register, the IVIS bit in the MODE register and
the ESTR bit in the EBICTL register. The E clock is available for use in external select decode logic or as
a constant speed clock for use in the external application system.
4.4.3.1.3 Normal Expanded Narrow Mode
This mode is used for lower cost production systems that use 8-bit wide external EPROMs or RAMs. Such
systems take extra bus cycles to access 16-bit locations but this may be preferred over the extra cost of
additional external memory devices.
Ports A and B are configured as a 16-bit address bus and Port A is multiplexed with data. Internal visibility
is not available in this mode because the internal cycles would need to be split into two 8-bit cycles.
Since the PEAR register can only be written one time in this mode, use care to set all bits to the desired
states during the single allowed write.
The PE3/LSTRB pin is always a general purpose I/O pin in normal expanded narrow mode. Although it is
possible to write the LSTRE bit in PEAR to “1” in this mode, the state of LSTRE is overridden and Port
E bit 3 cannot be reconfigured as the LSTRB output.
It is possible to enable the pipe status signals on Port E bits 6 and 5 by setting the PIPOE bit in PEAR, but
it would be unusual to do so in this mode. LSTRB would also be needed to fully understand system
activity. Development systems where pipe status signals are monitored would typically use special
expanded wide mode or occasionally special expanded narrow mode.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
154 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The PE4/ECLK pin is initially configured as ECLK output with stretch. The E clock output function
depends upon the settings of the NECLK bit in the PEAR register, the IVIS bit in the MODE register and
the ESTR bit in the EBICTL register. In normal expanded narrow mode, the E clock is available for use in
external select decode logic or as a constant speed clock for use in the external application system.
The PE2/R/W pin is initially configured as a general purpose input with an internal pull resistor enabled
but this pin can be reconfigured as the R/W bus control signal by writing “1” to the RDWE bit in PEAR.
If the expanded narrow system includes external devices that can be written such as RAM, the RDWE bit
would need to be set before any attempt to write to an external location. If there are no writable resources
in the external system, PE2 can be left as a general purpose I/O pin.
4.4.3.1.4 Emulation Expanded Wide Mode
In expanded wide modes, Ports A and B are configured as a 16-bit multiplexed address and data bus and
Port E provides bus control and status signals. These signals allow external memory and peripheral devices
to be interfaced to the MCU. These signals can also be used by a logic analyzer to monitor the progress of
application programs.
The bus control related pins in Port E (PE7/NOACC, PE6/MODB/IPIPE1, PE5/MODA/IPIPE0,
PE4/ECLK, PE3/LSTRB/TAGLO, and PE2/R/W) are all configured to serve their bus control output
functions rather than general purpose I/O. Notice that writes to the bus control enable bits in the PEAR
register in emulation mode are restricted.
4.4.3.1.5 Emulation Expanded Narrow Mode
Expanded narrow modes are intended to allow connection of single 8-bit external memory devices for
lower cost systems that do not need the performance of a full 16-bit external data bus. Accesses to internal
resources that have been mapped external (i.e. PORTA, PORTB, DDRA, DDRB, PORTE, DDRE, PEAR,
PUCR, RDRIV) will be accessed with a 16-bit data bus on Ports A and B. Accesses of 16-bit external
words to addresses which are normally mapped external will be broken into two separate 8-bit accesses
using Port A as an 8-bit data bus. Internal operations continue to use full 16-bit data paths. They are only
visible externally as 16-bit information if IVIS=1.
Ports A and B are configured as multiplexed address and data output ports. During external accesses,
address A15, data D15 and D7 are associated with PA7, address A0 is associated with PB0 and data D8
and D0 are associated with PA0. During internal visible accesses and accesses to internal resources that
have been mapped external, address A15 and data D15 is associated with PA7 and address A0 and data
D0 is associated with PB0.
The bus control related pins in Port E (PE7/NOACC, PE6/MODB/IPIPE1, PE5/MODA/IPIPE0,
PE4/ECLK, PE3/LSTRB/TAGLO, and PE2/R/W) are all configured to serve their bus control output
functions rather than general purpose I/O. Notice that writes to the bus control enable bits in the PEAR
register in emulation mode are restricted.
The main difference between special modes and normal modes is that some of the bus control and system
control signals cannot be written in emulation modes.
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 155
Rev 01.24
4.4.3.2 Special Operating Modes
There are two special operating modes that correspond to normal operating modes. These operating modes
are commonly used in factory testing and system development.
4.4.3.2.1 Special Single-Chip Mode
When the MCU is reset in this mode, the background debug mode is enabled and active. The MCU does
not fetch the reset vector and execute application code as it would in other modes. Instead the active
background mode is in control of CPU execution and BDM firmware is waiting for additional serial
commands through the BKGD pin. When a serial command instructs the MCU to return to normal
execution, the system will be configured as described below unless the reset states of internal control
registers have been changed through background commands after the MCU was reset.
There is no external expansion bus after reset in this mode. Ports A and B are initially simple bidirectional
I/O pins that are configured as high-impedance inputs with internal pull resistors disabled; however,
writing to the mode select bits in the MODE register (which is allowed in special modes) can change this
after reset. All of the Port E pins (except PE4/ECLK) are initially configured as general purpose high-
impedance inputs with internal pull resistors enabled. PE4/ECLK is configured as the E clock output in
this mode.
The pins associated with Port E bits 6, 5, 3, and 2 cannot be configured for their alternate functions IPIPE1,
IPIPE0, LSTRB, and R/W while the MCU is in single chip modes. In single chip modes, the associated
control bits PIPOE, LSTRE and RDWE are reset to zero. Writing the opposite value into these bits in
single chip mode does not change the operation of the associated Port E pins.
Port E, bit 4 can be configured for a free-running E clock output by clearing NECLK=0. Typically the only
use for an E clock output while the MCU is in single chip modes would be to get a constant speed clock
for use in the external application system.
4.4.3.2.2 Special Test Mode
In expanded wide modes, Ports A and B are configured as a 16-bit multiplexed address and data bus and
Port E provides bus control and status signals. In special test mode, the write protection of many control
bits is lifted so that they can be thoroughly tested without needing to go through reset.
4.4.3.3 Test Operating Mode
There is a test operating mode in which an external master, such as an I.C. tester, can control the on-chip
peripherals.
4.4.3.3.1 Peripheral Mode
This mode is intended for factory testing of the MCU. In this mode, the CPU is inactive and an external
(tester) bus master drives address, data and bus control signals in through Ports A, B and E. In effect, the
whole MCU acts as if it was a peripheral under control of an external CPU. This allows faster testing of
on-chip memory and peripherals than previous testing methods. Since the mode control register is not
accessible in peripheral mode, the only way to change to another mode is to reset the MCU into a different
Chapter 4 Multiplexed External Bus Interface (MEBIV3)
156 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
mode. Background debugging should not be used while the MCU is in special peripheral mode as internal
bus conflicts between BDM and the external master can cause improper operation of both functions.
4.4.4 Internal Visibility
Internal visibility is available when the MCU is operating in expanded wide modes or emulation narrow
mode. It is not available in single-chip, peripheral or normal expanded narrow modes. Internal visibility is
enabled by setting the IVIS bit in the MODE register.
If an internal access is made while E, R/W, and LSTRB are configured as bus control outputs and internal
visibility is off (IVIS=0), E will remain low for the cycle, R/W will remain high, and address, data and the
LSTRB pins will remain at their previous state.
When internal visibility is enabled (IVIS=1), certain internal cycles will be blocked from going external.
During cycles when the BDM is selected, R/W will remain high, data will maintain its previous state, and
address and LSTRB pins will be updated with the internal value. During CPU no access cycles when the
BDM is not driving, R/W will remain high, and address, data and the LSTRB pins will remain at their
previous state.
NOTE
When the system is operating in a secure mode, internal visibility is not
available (i.e., IVIS = 1 has no effect). Also, the IPIPE signals will not be
visible, regardless of operating mode. IPIPE1–IPIPE0 will display 0es if
they are enabled. In addition, the MOD bits in the MODE control register
cannot be written.
4.4.5 Low-Power Options
The MEBI does not contain any user-controlled options for reducing power consumption. The operation
of the MEBI in low-power modes is discussed in the following subsections.
4.4.5.1 Operation in Run Mode
The MEBI does not contain any options for reducing power in run mode; however, the external addresses
are conditioned to reduce power in single-chip modes. Expanded bus modes will increase power
consumption.
4.4.5.2 Operation in Wait Mode
The MEBI does not contain any options for reducing power in wait mode.
4.4.5.3 Operation in Stop Mode
The MEBI will cease to function after execution of a CPU STOP instruction.
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 157
Rev 01.24
Chapter 5
Interrupt (INTV1) Block Description
5.1 Introduction
This section describes the functionality of the interrupt (INT) sub-block of the S12 core platform.
A block diagram of the interrupt sub-block is shown in Figure 5-1.
Figure 5-1. INTV1 Block Diagram
HPRIO (OPTIONAL)
INT
PRIORITY DECODER
VECTOR REQUEST
INTERRUPTS
RESET FLAGS
WRITE DATA BUS
HPRIO VECTOR
XMASK
IMASK
QUALIFIED
INTERRUPT INPUT REGISTERS
INTERRUPTS
AND CONTROL REGISTERS
HIGHEST PRIORITY
I-INTERRUPT
READ DATA BUS
WAKEUP
VECTOR ADDRESS
INTERRUPT PENDING
Chapter 5 Interrupt (INTV1) Block Description
158 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The interrupt sub-block decodes the priority of all system exception requests and provides the applicable
vector for processing the exception. The INT supports I-bit maskable and X-bit maskable interrupts, a non-
maskable unimplemented opcode trap, a non-maskable software interrupt (SWI) or background debug
mode request, and three system reset vector requests. All interrupt related exception requests are managed
by the interrupt sub-block (INT).
5.1.1 Features
The INT includes these features:
• Provides two to 122 I-bit maskable interrupt vectors (0xFF00–0xFFF2)
• Provides one X-bit maskable interrupt vector (0xFFF4)
• Provides a non-maskable software interrupt (SWI) or background debug mode request vector
(0xFFF6)
• Provides a non-maskable unimplemented opcode trap (TRAP) vector (0xFFF8)
• Provides three system reset vectors (0xFFFA–0xFFFE) (reset, CMR, and COP)
• Determines the appropriate vector and drives it onto the address bus at the appropriate time
• Signals the CPU that interrupts are pending
• Provides control registers which allow testing of interrupts
• Provides additional input signals which prevents requests for servicing I and X interrupts
• Wakes the system from stop or wait mode when an appropriate interrupt occurs or whenever XIRQ
is active, even if XIRQ is masked
• Provides asynchronous path for all I and X interrupts, (0xFF00–0xFFF4)
• (Optional) selects and stores the highest priority I interrupt based on the value written into the
HPRIO register
5.1.2 Modes of Operation
The functionality of the INT sub-block in various modes of operation is discussed in the subsections that
follow.
• Normal operation
The INT operates the same in all normal modes of operation.
• Special operation
Interrupts may be tested in special modes through the use of the interrupt test registers.
• Emulation modes
The INT operates the same in emulation modes as in normal modes.
• Low power modes
See Section 5.4.1, “Low-Power Modes,” for details
Chapter 5 Interrupt (INTV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 159
Rev 01.24
5.2 External Signal Description
Most interfacing with the interrupt sub-block is done within the core. However, the interrupt does receive
direct input from the multiplexed external bus interface (MEBI) sub-block of the core for the IRQ and
XIRQ pin data.
5.3 Memory Map and Register Definition
Detailed descriptions of the registers and associated bits are given in the subsections that follow.
5.3.1 Module Memory Map
5.3.2 Register Descriptions
5.3.2.1 Interrupt Test Control Register
Read: See individual bit descriptions
Write: See individual bit descriptions
Table 5-1. INT Memory Map
Address
Offset Use Access
0x0015 Interrupt Test Control Register (ITCR) R/W
0x0016 Interrupt Test Registers (ITEST) R/W
0x001F Highest Priority Interrupt (Optional) (HPRIO) R/W
Module Base + 0x0015
Starting address location affected by INITRG register setting.
76543210
R000
WRTINT ADR3 ADR2 ADR1 ADR0
W
Reset 0 0 0 01111
= Unimplemented or Reserved
Figure 5-2. Interrupt Test Control Register (ITCR)
Chapter 5 Interrupt (INTV1) Block Description
160 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
5.3.2.2 Interrupt Test Registers
Read: Only in special modes. Reads will return either the state of the interrupt inputs of the interrupt sub-
block (WRTINT = 0) or the values written into the TEST registers (WRTINT = 1). Reads will always
return 0s in normal modes.
Write: Only in special modes and with WRTINT = 1 and CCR I mask = 1.
Table 5-2. ITCR Field Descriptions
Field Description
4
WRTINT
Write to the Interrupt Test Registers
Read: anytime
Write: only in special modes and with I-bit mask and X-bit mask set.
0 Disables writes to the test registers; reads of the test registers will return the state of the interrupt inputs.
1 Disconnect the interrupt inputs from the priority decoder and use the values written into the ITEST registers
instead.
Note: Any interrupts which are pending at the time that WRTINT is set will remain until they are overwritten.
3:0
ADR[3:0]
Test Register Select Bits
Read: anytime
Write: anytime
These bits determine which test register is selected on a read or write. The hexadecimal value written here will
be the same as the upper nibble of the lower byte of the vector selects. That is, an “F” written into ADR[3:0] will
select vectors 0xFFFE–0xFFF0 while a “7” written to ADR[3:0] will select vectors 0xFF7E–0xFF70.
Module Base + 0x0016
Starting address location affected by INITRG register setting.
76543210
R
INTE INTC INTA INT8 INT6 INT4 INT2 INT0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 5-3. Interrupt TEST Registers (ITEST)
Chapter 5 Interrupt (INTV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 161
Rev 01.24
5.3.2.3 Highest Priority I Interrupt (Optional)
Read: Anytime
Write: Only if I mask in CCR = 1
5.4 Functional Description
The interrupt sub-block processes all exception requests made by the CPU. These exceptions include
interrupt vector requests and reset vector requests. Each of these exception types and their overall priority
level is discussed in the subsections below.
Table 5-3. ITEST Field Descriptions
Field Description
7:0
INT[E:0]
Interrupt TEST Bits — These registers are used in special modes for testing the interrupt logic and priority
independent of the system configuration. Each bit is used to force a specific interrupt vector by writing it to a
logic 1 state. Bits are named INTE through INT0 to indicate vectors 0xFFxE through 0xFFx0. These bits can be
written only in special modes and only with the WRTINT bit set (logic 1) in the interrupt test control register
(ITCR). In addition, I interrupts must be masked using the I bit in the CCR. In this state, the interrupt input lines
to the interrupt sub-block will be disconnected and interrupt requests will be generated only by this register.
These bits can also be read in special modes to view that an interrupt requested by a system block (such as a
peripheral block) has reached the INT module.
There is a test register implemented for every eight interrupts in the overall system. All of the test registers share
the same address and are individually selected using the value stored in the ADR[3:0] bits of the interrupt test
control register (ITCR).
Note: When ADR[3:0] have the value of 0x000F, only bits 2:0 in the ITEST register will be accessible. That is,
vectors higher than 0xFFF4 cannot be tested using the test registers and bits 7:3 will always read as a
logic 0. If ADR[3:0] point to an unimplemented test register, writes will have no effect and reads will always
return a logic 0 value.
Module Base + 0x001F
Starting address location affected by INITRG register setting.
76543210
R
PSEL7 PSEL6 PSEL5 PSEL4 PSEL3 PSEL2 PSEL1
0
W
Reset 1 1 1 10010
= Unimplemented or Reserved
Figure 5-4. Highest Priority I Interrupt Register (HPRIO)
Table 5-4. HPRIO Field Descriptions
Field Description
7:1
PSEL[7:1]
Highest Priority I Interrupt Select Bits — The state of these bits determines which I-bit maskable interrupt will
be promoted to highest priority (of the I-bit maskable interrupts). To promote an interrupt, the user writes the least
significant byte of the associated interrupt vector address to this register. If an unimplemented vector address or
a non I-bit masked vector address (value higher than 0x00F2) is written, IRQ (0xFFF2) will be the default highest
priority interrupt.
Chapter 5 Interrupt (INTV1) Block Description
162 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
5.4.1 Low-Power Modes
The INT does not contain any user-controlled options for reducing power consumption. The operation of
the INT in low-power modes is discussed in the following subsections.
5.4.1.1 Operation in Run Mode
The INT does not contain any options for reducing power in run mode.
5.4.1.2 Operation in Wait Mode
Clocks to the INT can be shut off during system wait mode and the asynchronous interrupt path will be
used to generate the wake-up signal upon recognition of a valid interrupt or any XIRQ request.
5.4.1.3 Operation in Stop Mode
Clocks to the INT can be shut off during system stop mode and the asynchronous interrupt path will be
used to generate the wake-up signal upon recognition of a valid interrupt or any XIRQ request.
5.5 Resets
The INT supports three system reset exception request types: normal system reset or power-on-reset
request, crystal monitor reset request, and COP watchdog reset request. The type of reset exception request
must be decoded by the system and the proper request made to the core. The INT will then provide the
service routine address for the type of reset requested.
5.6 Interrupts
As shown in the block diagram in Figure 5-1, the INT contains a register block to provide interrupt status
and control, an optional highest priority I interrupt (HPRIO) block, and a priority decoder to evaluate
whether pending interrupts are valid and assess their priority.
5.6.1 Interrupt Registers
The INT registers are accessible only in special modes of operation and function as described in
Section 5.3.2.1, “Interrupt Test Control Register,” and Section 5.3.2.2, “Interrupt Test Registers,”
previously.
5.6.2 Highest Priority I-Bit Maskable Interrupt
When the optional HPRIO block is implemented, the user is allowed to promote a single I-bit maskable
interrupt to be the highest priority I interrupt. The HPRIO evaluates all interrupt exception requests and
passes the HPRIO vector to the priority decoder if the highest priority I interrupt is active. RTI replaces
the promoted interrupt source.
Chapter 5 Interrupt (INTV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 163
Rev 01.24
5.6.3 Interrupt Priority Decoder
The priority decoder evaluates all interrupts pending and determines their validity and priority. When the
CPU requests an interrupt vector, the decoder will provide the vector for the highest priority interrupt
request. Because the vector is not supplied until the CPU requests it, it is possible that a higher priority
interrupt request could override the original exception that caused the CPU to request the vector. In this
case, the CPU will receive the highest priority vector and the system will process this exception instead of
the original request.
NOTE
Care must be taken to ensure that all exception requests remain active until
the system begins execution of the applicable service routine; otherwise, the
exception request may not be processed.
If for any reason the interrupt source is unknown (e.g., an interrupt request becomes inactive after the
interrupt has been recognized but prior to the vector request), the vector address will default to that of the
last valid interrupt that existed during the particular interrupt sequence. If the CPU requests an interrupt
vector when there has never been a pending interrupt request, the INT will provide the software interrupt
(SWI) vector address.
5.7 Exception Priority
The priority (from highest to lowest) and address of all exception vectors issued by the INT upon request
by the CPU is shown in Table 5-5.
Table 5-5. Exception Vector Map and Priority
Vector Address Source
0xFFFE–0xFFFF System reset
0xFFFC–0xFFFD Crystal monitor reset
0xFFFA–0xFFFB COP reset
0xFFF8–0xFFF9 Unimplemented opcode trap
0xFFF6–0xFFF7 Software interrupt instruction (SWI) or BDM vector request
0xFFF4–0xFFF5 XIRQ signal
0xFFF2–0xFFF3 IRQ signal
0xFFF0–0xFF00 Device-specific I-bit maskable interrupt sources (priority in descending order)
Chapter 5 Interrupt (INTV1) Block Description
164 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 165
Rev 01.24
Chapter 6
Background Debug Module (BDMV4) Block Description
6.1 Introduction
This section describes the functionality of the background debug module (BDM) sub-block of the HCS12
core platform.
A block diagram of the BDM is shown in Figure 6-1.
Figure 6-1. BDM Block Diagram
The background debug module (BDM) sub-block is a single-wire, background debug system implemented
in on-chip hardware for minimal CPU intervention. All interfacing with the BDM is done via the BKGD
pin.
BDMV4 has enhanced capability for maintaining synchronization between the target and host while
allowing more flexibility in clock rates. This includes a sync signal to show the clock rate and a handshake
signal to indicate when an operation is complete. The system is backwards compatible with older external
interfaces.
6.1.1 Features
• Single-wire communication with host development system
• BDMV4 (and BDM2): Enhanced capability for allowing more flexibility in clock rates
• BDMV4: SYNC command to determine communication rate
• BDMV4: GO_UNTIL command
• BDMV4: Hardware handshake protocol to increase the performance of the serial communication
• Active out of reset in special single-chip mode
ENBDM
SDV
16-BIT SHIFT REGISTER
BKGD
CLOCKS
DATA
ADDRESS
HOST
SYSTEM
BUS INTERFACE
AND
CONTROL LOGIC
INSTRUCTION DECODE
AND EXECUTION
STANDARD BDM
FIRMWARE
LOOKUP TABLE
CLKSW
BDMACT
ENTAG
TRACE
Chapter 6 Background Debug Module (BDMV4) Block Description
166 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
• Nine hardware commands using free cycles, if available, for minimal CPU intervention
• Hardware commands not requiring active BDM
• 15 firmware commands execute from the standard BDM firmware lookup table
• Instruction tagging capability
• Software control of BDM operation during wait mode
• Software selectable clocks
• When secured, hardware commands are allowed to access the register space in special single-chip
mode, if the FLASH and EEPROM erase tests fail.
6.1.2 Modes of Operation
BDM is available in all operating modes but must be enabled before firmware commands are executed.
Some system peripherals may have a control bit which allows suspending the peripheral function during
background debug mode.
6.1.2.1 Regular Run Modes
All of these operations refer to the part in run mode. The BDM does not provide controls to conserve power
during run mode.
• Normal operation
General operation of the BDM is available and operates the same in all normal modes.
• Special single-chip mode
In special single-chip mode, background operation is enabled and active out of reset. This allows
programming a system with blank memory.
• Special peripheral mode
BDM is enabled and active immediately out of reset. BDM can be disabled by clearing the
BDMACT bit in the BDM status (BDMSTS) register. The BDM serial system should not be used
in special peripheral mode.
NOTE
The BDM serial system should not be used in special peripheral mode since
the CPU, which in other modes interfaces with the BDM to relinquish
control of the bus during a free cycle or a steal operation, is not operating in
this mode.
• Emulation modes
General operation of the BDM is available and operates the same as in normal modes.
6.1.2.2 Secure Mode Operation
If the part is in secure mode, the operation of the BDM is reduced to a small subset of its regular run mode
operation. Secure operation prevents access to FLASH or EEPROM other than allowing erasure.
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 167
Rev 01.24
6.2 External Signal Description
A single-wire interface pin is used to communicate with the BDM system. Two additional pins are used
for instruction tagging. These pins are part of the multiplexed external bus interface (MEBI) sub-block and
all interfacing between the MEBI and BDM is done within the core interface boundary. Functional
descriptions of the pins are provided below for completeness.
• BKGD — Background interface pin
•TAGHI — High byte instruction tagging pin
•TAGLO — Low byte instruction tagging pin
• BKGD and TAGHI share the same pin.
•TAGLO and LSTRB share the same pin.
NOTE
Generally these pins are shared as described, but it is best to check the
device overview chapter to make certain. All MCUs at the time of this
writing have followed this pin sharing scheme.
6.2.1 BKGD — Background Interface Pin
Debugging control logic communicates with external devices serially via the single-wire background
interface pin (BKGD). During reset, this pin is a mode select input which selects between normal and
special modes of operation. After reset, this pin becomes the dedicated serial interface pin for the
background debug mode.
6.2.2 TAGHI — High Byte Instruction Tagging Pin
This pin is used to tag the high byte of an instruction. When instruction tagging is on, a logic 0 at the falling
edge of the external clock (ECLK) tags the high half of the instruction word being read into the instruction
queue.
6.2.3 TAGLO — Low Byte Instruction Tagging Pin
This pin is used to tag the low byte of an instruction. When instruction tagging is on and low strobe is
enabled, a logic 0 at the falling edge of the external clock (ECLK) tags the low half of the instruction word
being read into the instruction queue.
Chapter 6 Background Debug Module (BDMV4) Block Description
168 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
6.3 Memory Map and Register Definition
A summary of the registers associated with the BDM is shown in Figure 6-2. Registers are accessed by
host-driven communications to the BDM hardware using READ_BD and WRITE_BD commands.
Detailed descriptions of the registers and associated bits are given in the subsections that follow.
6.3.1 Module Memory Map
Table 6-1. INT Memory Map
Register
Address Use Access
0xFF00 Reserved —
0xFF01 BDM Status Register (BDMSTS) R/W
0xFF02–
0xFF05
Reserved —
0xFF06 BDM CCR Holding Register (BDMCCR) R/W
0xFF07 BDM Internal Register Position (BDMINR) R
0xFF08–
0xFF0B
Reserved —
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 169
Rev 01.24
6.3.2 Register Descriptions
Register
Name Bit 7 6 5 4321Bit 0
0xFF00
Reserved
RXXXXXX00
W
0xFF01
BDMSTS
RENBDM BDMACT ENTAG SDV TRACE CLKSW UNSEC 0
W
0xFF02
Reserved
RXXXXXXXX
W
0xFF03
Reserved
RXXXXXXXX
W
0xFF04
Reserved
RXXXXXXXX
W
0xFF05
Reserved
RXXXXXXXX
W
0xFF06
BDMCCR
RCCR7 CCR6 CCR5 CCR4 CCR3 CCR2 CCR1 CCR0
W
0xFF07
BDMINR
R 0 REG14 REG13 REG12 REG11 0 0 0
W
0xFF08
Reserved
R00000000
W
0xFF09
Reserved
R00000000
W
0xFF0A
Reserved
RXXXXXXXX
W
0xFF0B
Reserved
RXXXXXXXX
W
= Unimplemented, Reserved = Implemented (do not alter)
X = Indeterminate 0 = Always read zero
Figure 6-2. BDM Register Summary
Chapter 6 Background Debug Module (BDMV4) Block Description
170 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
6.3.2.1 BDM Status Register (BDMSTS)
Read: All modes through BDM operation
Write: All modes but subject to the following:
• BDMACT can only be set by BDM hardware upon entry into BDM. It can only be cleared by the
standard BDM firmware lookup table upon exit from BDM active mode.
• CLKSW can only be written via BDM hardware or standard BDM firmware write commands.
• All other bits, while writable via BDM hardware or standard BDM firmware write commands,
should only be altered by the BDM hardware or standard firmware lookup table as part of BDM
command execution.
• ENBDM should only be set via a BDM hardware command if the BDM firmware commands are
needed. (This does not apply in special single-chip mode).
0xFF01
76543210
RENBDM BDMACT ENTAG SDV TRACE CLKSW UNSEC 0
W
Reset:
Special single-chip mode:
Special peripheral mode:
All other modes:
1(1)
0
0
0
1. ENBDM is read as "1" by a debugging environment in Special single-chip mode when the device is not secured or secured
but fully erased (Flash and EEPROM).This is because the ENBDM bit is set by the standard firmware before a BDM command
can be fully transmitted and executed.
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0(2)
0
0
0
2. UNSEC is read as "1" by a debugging environment in Special single-chip mode when the device is secured and fully erased,
else it is "0" and can only be read if not secure (see also bit description).
0
0
0
0
= Unimplemented or Reserved = Implemented (do not alter)
Figure 6-3. BDM Status Register (BDMSTS)
Note:
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 171
Rev 01.24
Table 6-2. BDMSTS Field Descriptions
Field Description
7
ENBDM
Enable BDM — This bit controls whether the BDM is enabled or disabled. When enabled, BDM can be made
active to allow firmware commands to be executed. When disabled, BDM cannot be made active but BDM
hardware commands are allowed.
0 BDM disabled
1 BDM enabled
Note: ENBDM is set by the firmware immediately out of reset in special single-chip mode. In secure mode, this
bit will not be set by the firmware until after the EEPROM and FLASH erase verify tests are complete.
6
BDMACT
BDM Active Status — This bit becomes set upon entering BDM. The standard BDM firmware lookup table is
then enabled and put into the memory map. BDMACT is cleared by a carefully timed store instruction in the
standard BDM firmware as part of the exit sequence to return to user code and remove the BDM memory from
the map.
0 BDM not active
1 BDM active
5
ENTAG
Tagging Enable — This bit indicates whether instruction tagging in enabled or disabled. It is set when the
TAGGO command is executed and cleared when BDM is entered. The serial system is disabled and the tag
function enabled 16 cycles after this bit is written. BDM cannot process serial commands while tagging is active.
0 Tagging not enabled or BDM active
1 Tagging enabled
4
SDV
Shift Data Valid — This bit is set and cleared by the BDM hardware. It is set after data has been transmitted as
part of a firmware read command or after data has been received as part of a firmware write command. It is
cleared when the next BDM command has been received or BDM is exited. SDV is used by the standard BDM
firmware to control program flow execution.
0 Data phase of command not complete
1 Data phase of command is complete
3
TRACE
TRACE1 BDM Firmware Command is Being Executed — This bit gets set when a BDM TRACE1 firmware
command is first recognized. It will stay set as long as continuous back-to-back TRACE1 commands are
executed. This bit will get cleared when the next command that is not a TRACE1 command is recognized.
0 TRACE1 command is not being executed
1 TRACE1 command is being executed
Chapter 6 Background Debug Module (BDMV4) Block Description
172 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
2
CLKSW
Clock Switch — The CLKSW bit controls which clock the BDM operates with. It is only writable from a hardware
BDM command. A 150 cycle delay at the clock speed that is active during the data portion of the command will
occur before the new clock source is guaranteed to be active. The start of the next BDM command uses the new
clock for timing subsequent BDM communications.
Table 6-3 shows the resulting BDM clock source based on the CLKSW and the PLLSEL (Pll select from the clock
and reset generator) bits.
Note: The BDM alternate clock source can only be selected when CLKSW = 0 and PLLSEL = 1. The BDM serial
interface is now fully synchronized to the alternate clock source, when enabled. This eliminates frequency
restriction on the alternate clock which was required on previous versions. Refer to the device overview
section to determine which clock connects to the alternate clock source input.
Note: If the acknowledge function is turned on, changing the CLKSW bit will cause the ACK to be at the new rate
for the write command which changes it.
1
UNSEC
Unsecure — This bit is only writable in special single-chip mode from the BDM secure firmware and always gets
reset to zero. It is in a zero state as secure mode is entered so that the secure BDM firmware lookup table is
enabled and put into the memory map along with the standard BDM firmware lookup table.
The secure BDM firmware lookup table verifies that the on-chip EEPROM and FLASH EEPROM are erased. This
being the case, the UNSEC bit is set and the BDM program jumps to the start of the standard BDM firmware
lookup table and the secure BDM firmware lookup table is turned off. If the erase test fails, the UNSEC bit will
not be asserted.
0 System is in a secured mode
1 System is in a unsecured mode
Note: When UNSEC is set, security is off and the user can change the state of the secure bits in the on-chip
FLASH EEPROM. Note that if the user does not change the state of the bits to “unsecured” mode, the
system will be secured again when it is next taken out of reset.
Table 6-3. BDM Clock Sources
PLLSEL CLKSW BDMCLK
0 0 Bus clock
0 1 Bus clock
1 0 Alternate clock (refer to the device overview chapter to determine the alternate clock
source)
1 1 Bus clock dependent on the PLL
Table 6-2. BDMSTS Field Descriptions (continued)
Field Description
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 173
Rev 01.24
6.3.2.2 BDM CCR Holding Register (BDMCCR)
Read: All modes
Write: All modes
NOTE
When BDM is made active, the CPU stores the value of the CCR register in
the BDMCCR register. However, out of special single-chip reset, the
BDMCCR is set to 0xD8 and not 0xD0 which is the reset value of the CCR
register.
When entering background debug mode, the BDM CCR holding register is used to save the contents of the
condition code register of the user’s program. It is also used for temporary storage in the standard BDM
firmware mode. The BDM CCR holding register can be written to modify the CCR value.
6.3.2.3 BDM Internal Register Position Register (BDMINR)
Read: All modes
Write: Never
0xFF06
76543210
RCCR7 CCR6 CCR5 CCR4 CCR3 CCR2 CCR1 CCR0
W
Reset 0 0 0 00000
Figure 6-4. BDM CCR Holding Register (BDMCCR)
0xFF07
76543210
R 0 REG14 REG13 REG12 REG11 0 0 0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 6-5. BDM Internal Register Position (BDMINR)
Table 6-4. BDMINR Field Descriptions
Field Description
6:3
REG[14:11]
Internal Register Map Position — These four bits show the state of the upper five bits of the base address for
the system’s relocatable register block. BDMINR is a shadow of the INITRG register which maps the register
block to any 2K byte space within the first 32K bytes of the 64K byte address space.
Chapter 6 Background Debug Module (BDMV4) Block Description
174 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
6.4 Functional Description
The BDM receives and executes commands from a host via a single wire serial interface. There are two
types of BDM commands, namely, hardware commands and firmware commands.
Hardware commands are used to read and write target system memory locations and to enter active
background debug mode, see Section 6.4.3, “BDM Hardware Commands.” Target system memory
includes all memory that is accessible by the CPU.
Firmware commands are used to read and write CPU resources and to exit from active background debug
mode, see Section 6.4.4, “Standard BDM Firmware Commands.” The CPU resources referred to are the
accumulator (D), X index register (X), Y index register (Y), stack pointer (SP), and program counter (PC).
Hardware commands can be executed at any time and in any mode excluding a few exceptions as
highlighted, see Section 6.4.3, “BDM Hardware Commands.” Firmware commands can only be executed
when the system is in active background debug mode (BDM).
6.4.1 Security
If the user resets into special single-chip mode with the system secured, a secured mode BDM firmware
lookup table is brought into the map overlapping a portion of the standard BDM firmware lookup table.
The secure BDM firmware verifies that the on-chip EEPROM and FLASH EEPROM are erased. This
being the case, the UNSEC bit will get set. The BDM program jumps to the start of the standard BDM
firmware and the secured mode BDM firmware is turned off and all BDM commands are allowed. If the
EEPROM or FLASH do not verify as erased, the BDM firmware sets the ENBDM bit, without asserting
UNSEC, and the firmware enters a loop. This causes the BDM hardware commands to become enabled,
but does not enable the firmware commands. This allows the BDM hardware to be used to erase the
EEPROM and FLASH. After execution of the secure firmware, regardless of the results of the erase tests,
the CPU registers, INITEE and PPAGE, will no longer be in their reset state.
6.4.2 Enabling and Activating BDM
The system must be in active BDM to execute standard BDM firmware commands. BDM can be activated
only after being enabled. BDM is enabled by setting the ENBDM bit in the BDM status (BDMSTS)
register. The ENBDM bit is set by writing to the BDM status (BDMSTS) register, via the single-wire
interface, using a hardware command such as WRITE_BD_BYTE.
After being enabled, BDM is activated by one of the following1:
• Hardware BACKGROUND command
• BDM external instruction tagging mechanism
• CPU BGND instruction
• Breakpoint sub-block’s force or tag mechanism2
When BDM is activated, the CPU finishes executing the current instruction and then begins executing the
firmware in the standard BDM firmware lookup table. When BDM is activated by the breakpoint sub-
1. BDM is enabled and active immediately out of special single-chip reset.
2. This method is only available on systems that have a a breakpoint or a debug sub-block.
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 175
Rev 01.24
block, the type of breakpoint used determines if BDM becomes active before or after execution of the next
instruction.
NOTE
If an attempt is made to activate BDM before being enabled, the CPU
resumes normal instruction execution after a brief delay. If BDM is not
enabled, any hardware BACKGROUND commands issued are ignored by
the BDM and the CPU is not delayed.
In active BDM, the BDM registers and standard BDM firmware lookup table are mapped to addresses
0xFF00 to 0xFFFF. BDM registers are mapped to addresses 0xFF00 to 0xFF07. The BDM uses these
registers which are readable anytime by the BDM. However, these registers are not readable by user
programs.
6.4.3 BDM Hardware Commands
Hardware commands are used to read and write target system memory locations and to enter active
background debug mode. Target system memory includes all memory that is accessible by the CPU such
as on-chip RAM, EEPROM, FLASH EEPROM, I/O and control registers, and all external memory.
Hardware commands are executed with minimal or no CPU intervention and do not require the system to
be in active BDM for execution, although they can continue to be executed in this mode. When executing
a hardware command, the BDM sub-block waits for a free CPU bus cycle so that the background access
does not disturb the running application program. If a free cycle is not found within 128 clock cycles, the
CPU is momentarily frozen so that the BDM can steal a cycle. When the BDM finds a free cycle, the
operation does not intrude on normal CPU operation provided that it can be completed in a single cycle.
However, if an operation requires multiple cycles the CPU is frozen until the operation is complete, even
though the BDM found a free cycle.
Chapter 6 Background Debug Module (BDMV4) Block Description
176 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The BDM hardware commands are listed in Table 6-5.
NOTE:
If enabled, ACK will occur when data is ready for transmission for all BDM READ commands and will occur after the write is
complete for all BDM WRITE commands.
The READ_BD and WRITE_BD commands allow access to the BDM register locations. These locations
are not normally in the system memory map but share addresses with the application in memory. To
distinguish between physical memory locations that share the same address, BDM memory resources are
enabled just for the READ_BD and WRITE_BD access cycle. This allows the BDM to access BDM
locations unobtrusively, even if the addresses conflict with the application memory map.
6.4.4 Standard BDM Firmware Commands
Firmware commands are used to access and manipulate CPU resources. The system must be in active
BDM to execute standard BDM firmware commands, see Section 6.4.2, “Enabling and Activating BDM.”
Normal instruction execution is suspended while the CPU executes the firmware located in the standard
BDM firmware lookup table. The hardware command BACKGROUND is the usual way to activate BDM.
As the system enters active BDM, the standard BDM firmware lookup table and BDM registers become
visible in the on-chip memory map at 0xFF00–0xFFFF, and the CPU begins executing the standard BDM
Table 6-5. Hardware Commands
Command Opcode
(hex) Data Description
BACKGROUND 90 None Enter background mode if firmware is enabled. If enabled, an ACK will
be issued when the part enters active background mode.
ACK_ENABLE D5 None Enable handshake. Issues an ACK pulse after the command is
executed.
ACK_DISABLE D6 None Disable handshake. This command does not issue an ACK pulse.
READ_BD_BYTE E4 16-bit address
16-bit data out
Read from memory with standard BDM firmware lookup table in map.
Odd address data on low byte; even address data on high byte.
READ_BD_WORD EC 16-bit address
16-bit data out
Read from memory with standard BDM firmware lookup table in map.
Must be aligned access.
READ_BYTE E0 16-bit address
16-bit data out
Read from memory with standard BDM firmware lookup table out of
map. Odd address data on low byte; even address data on high byte.
READ_WORD E8 16-bit address
16-bit data out
Read from memory with standard BDM firmware lookup table out of
map. Must be aligned access.
WRITE_BD_BYTE C4 16-bit address
16-bit data in
Write to memory with standard BDM firmware lookup table in map. Odd
address data on low byte; even address data on high byte.
WRITE_BD_WORD CC 16-bit address
16-bit data in
Write to memory with standard BDM firmware lookup table in map. Must
be aligned access.
WRITE_BYTE C0 16-bit address
16-bit data in
Write to memory with standard BDM firmware lookup table out of map.
Odd address data on low byte; even address data on high byte.
WRITE_WORD C8 16-bit address
16-bit data in
Write to memory with standard BDM firmware lookup table out of map.
Must be aligned access.
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 177
Rev 01.24
firmware. The standard BDM firmware watches for serial commands and executes them as they are
received.
The firmware commands are shown in Table 6-6.
6.4.5 BDM Command Structure
Hardware and firmware BDM commands start with an 8-bit opcode followed by a 16-bit address and/or a
16-bit data word depending on the command. All the read commands return 16 bits of data despite the byte
or word implication in the command name.
NOTE
8-bit reads return 16-bits of data, of which, only one byte will contain valid
data. If reading an even address, the valid data will appear in the MSB. If
reading an odd address, the valid data will appear in the LSB.
Table 6-6. Firmware Commands
Command(1)
1. If enabled, ACK will occur when data is ready for transmission for all BDM READ commands and will occur after the write is
complete for all BDM WRITE commands.
Opcode (hex) Data Description
READ_NEXT 62 16-bit data out Increment X by 2 (X = X + 2), then read word X points to.
READ_PC 63 16-bit data out Read program counter.
READ_D 64 16-bit data out Read D accumulator.
READ_X 65 16-bit data out Read X index register.
READ_Y 66 16-bit data out Read Y index register.
READ_SP 67 16-bit data out Read stack pointer.
WRITE_NEXT 42 16-bit data in Increment X by 2 (X = X + 2), then write word to location pointed to by X.
WRITE_PC 43 16-bit data in Write program counter.
WRITE_D 44 16-bit data in Write D accumulator.
WRITE_X 45 16-bit data in Write X index register.
WRITE_Y 46 16-bit data in Write Y index register.
WRITE_SP 47 16-bit data in Write stack pointer.
GO 08 None Go to user program. If enabled, ACK will occur when leaving active
background mode.
GO_UNTIL(2)
2. Both WAIT (with clocks to the S12 CPU core disabled) and STOP disable the ACK function. The GO_UNTIL command will not
get an Acknowledge if one of these two CPU instructions occurs before the “UNTIL” instruction. This can be a problem for any
instruction that uses ACK, but GO_UNTIL is a lot more difficult for the development tool to time-out.
0C None Go to user program. If enabled, ACK will occur upon returning to active
background mode.
TRACE1 10 None Execute one user instruction then return to active BDM. If enabled, ACK
will occur upon returning to active background mode.
TAGGO 18 None Enable tagging and go to user program. There is no ACK pulse related to
this command.
Chapter 6 Background Debug Module (BDMV4) Block Description
178 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
NOTE
16-bit misaligned reads and writes are not allowed. If attempted, the BDM
will ignore the least significant bit of the address and will assume an even
address from the remaining bits.
For hardware data read commands, the external host must wait 150 bus clock cycles after sending the
address before attempting to obtain the read data. This is to be certain that valid data is available in the
BDM shift register, ready to be shifted out. For hardware write commands, the external host must wait
150 bus clock cycles after sending the data to be written before attempting to send a new command. This
is to avoid disturbing the BDM shift register before the write has been completed. The 150 bus clock cycle
delay in both cases includes the maximum 128 cycle delay that can be incurred as the BDM waits for a
free cycle before stealing a cycle.
For firmware read commands, the external host should wait 44 bus clock cycles after sending the command
opcode and before attempting to obtain the read data. This includes the potential of an extra 7 cycles when
the access is external with a narrow bus access (+1 cycle) and / or a stretch (+1, 2, or 3 cycles), (7 cycles
could be needed if both occur). The 44 cycle wait allows enough time for the requested data to be made
available in the BDM shift register, ready to be shifted out.
NOTE
This timing has increased from previous BDM modules due to the new
capability in which the BDM serial interface can potentially run faster than
the bus. On previous BDM modules this extra time could be hidden within
the serial time.
For firmware write commands, the external host must wait 32 bus clock cycles after sending the data to be
written before attempting to send a new command. This is to avoid disturbing the BDM shift register
before the write has been completed.
The external host should wait 64 bus clock cycles after a TRACE1 or GO command before starting any
new serial command. This is to allow the CPU to exit gracefully from the standard BDM firmware lookup
table and resume execution of the user code. Disturbing the BDM shift register prematurely may adversely
affect the exit from the standard BDM firmware lookup table.
NOTE
If the bus rate of the target processor is unknown or could be changing, it is
recommended that the ACK (acknowledge function) be used to indicate
when an operation is complete. When using ACK, the delay times are
automated.
Figure 6-6 represents the BDM command structure. The command blocks illustrate a series of eight bit
times starting with a falling edge. The bar across the top of the blocks indicates that the BKGD line idles
in the high state. The time for an 8-bit command is 8 × 16 target clock cycles.1
1. Target clock cycles are cycles measured using the target MCU’s serial clock rate. See Section 6.4.6, “BDM Serial Interface,”
and Section 6.3.2.1, “BDM Status Register (BDMSTS),” for information on how serial clock rate is selected.
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 179
Rev 01.24
Figure 6-6. BDM Command Structure
6.4.6 BDM Serial Interface
The BDM communicates with external devices serially via the BKGD pin. During reset, this pin is a mode
select input which selects between normal and special modes of operation. After reset, this pin becomes
the dedicated serial interface pin for the BDM.
The BDM serial interface is timed using the clock selected by the CLKSW bit in the status register see
Section 6.3.2.1, “BDM Status Register (BDMSTS).” This clock will be referred to as the target clock in
the following explanation.
The BDM serial interface uses a clocking scheme in which the external host generates a falling edge on
the BKGD pin to indicate the start of each bit time. This falling edge is sent for every bit whether data is
transmitted or received. Data is transferred most significant bit (MSB) first at 16 target clock cycles per
bit. The interface times out if 512 clock cycles occur between falling edges from the host.
The BKGD pin is a pseudo open-drain pin and has an weak on-chip active pull-up that is enabled at all
times. It is assumed that there is an external pull-up and that drivers connected to BKGD do not typically
drive the high level. Because R-C rise time could be unacceptably long, the target system and host provide
brief driven-high (speedup) pulses to drive BKGD to a logic 1. The source of this speedup pulse is the host
for transmit cases and the target for receive cases.
The timing for host-to-target is shown in Figure 6-7 and that of target-to-host in Figure 6-8 and Figure 6-
9. All four cases begin when the host drives the BKGD pin low to generate a falling edge. Because the host
and target are operating from separate clocks, it can take the target system up to one full clock cycle to
recognize this edge. The target measures delays from this perceived start of the bit time while the host
measures delays from the point it actually drove BKGD low to start the bit up to one target clock cycle
HARDWARE
HARDWARE
FIRMWARE
FIRMWARE
GO,
44-BC
BC = BUS CLOCK CYCLES
COMMAND ADDRESS
150-BC
DELAY
NEXT
DELAY
8 BITS
AT ∼16 TC/BIT
16 BITS
AT ∼16 TC/BIT
16 BITS
AT ∼16 TC/BIT
COMMAND ADDRESS DATA NEXT
DATA
READ
WRITE
READ
WRITE
TRACE
COMMAND NEXT
COMMAND DATA
64-BC
DELAY
NEXT
COMMAND
150-BC
DELAY
32-BC
DELAY
COMMAND
COMMAND
COMMAND
COMMAND
DATA
NEXT
COMMAND
TC = TARGET CLOCK CYCLES
Chapter 6 Background Debug Module (BDMV4) Block Description
180 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
earlier. Synchronization between the host and target is established in this manner at the start of every bit
time.
Figure 6-7 shows an external host transmitting a logic 1 and transmitting a logic 0 to the BKGD pin of a
target system. The host is asynchronous to the target, so there is up to a one clock-cycle delay from the
host-generated falling edge to where the target recognizes this edge as the beginning of the bit time. Ten
target clock cycles later, the target senses the bit level on the BKGD pin. Internal glitch detect logic
requires the pin be driven high no later that eight target clock cycles after the falling edge for a logic 1
transmission.
Because the host drives the high speedup pulses in these two cases, the rising edges look like digitally
driven signals.
Figure 6-7. BDM Host-to-Target Serial Bit Timing
The receive cases are more complicated. Figure 6-8 shows the host receiving a logic 1 from the target
system. Because the host is asynchronous to the target, there is up to one clock-cycle delay from the host-
generated falling edge on BKGD to the perceived start of the bit time in the target. The host holds the
BKGD pin low long enough for the target to recognize it (at least two target clock cycles). The host must
release the low drive before the target drives a brief high speedup pulse seven target clock cycles after the
perceived start of the bit time. The host should sample the bit level about 10 target clock cycles after it
started the bit time.
EARLIEST
START OF
NEXT BIT
TARGET SENSES BIT
10 CYCLES
SYNCHRONIZATION
UNCERTAINTY
CLOCK
TARGET SYSTEM
HOST
TRANSMIT 1
HOST
TRANSMIT 0
PERCEIVED
S
TART OF BIT TIME
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 181
Rev 01.24
Figure 6-8. BDM Target-to-Host Serial Bit Timing (Logic 1)
Figure 6-9 shows the host receiving a logic 0 from the target. Because the host is asynchronous to the
target, there is up to a one clock-cycle delay from the host-generated falling edge on BKGD to the start of
the bit time as perceived by the target. The host initiates the bit time but the target finishes it. Because the
target wants the host to receive a logic 0, it drives the BKGD pin low for 13 target clock cycles then briefly
drives it high to speed up the rising edge. The host samples the bit level about 10 target clock cycles after
starting the bit time.
Figure 6-9. BDM Target-to-Host Serial Bit Timing (Logic 0)
HIGH-IMPEDANCE
EARLIEST
START OF
NEXT BIT
R-C RISE
10 CYCLES
10 CYCLES
HOST SAMPLES
BKGD PIN
PERCEIVED
START OF BIT TIME
BKGD PIN
CLOCK
TARGET SYSTEM
HOST
DRIVE TO
BKGD PIN
TARGET SYSTEM
SPEEDUP
PULSE
HIGH-IMPEDANCE
HIGH-IMPEDANCE
EARLIEST
START OF
NEXT BIT
CLOCK
TARGET SYS.
HOST
DRIVE TO
BKGD PIN
BKGD PIN
PERCEIVED
START OF BIT TIME
10 CYCLES
10 CYCLES
HOST SAMPLES
BKGD PIN
TARGET SYS.
DRIVE AND
SPEEDUP PULSE
SPEEDUP PULSE
HIGH-IMPEDANCE
Chapter 6 Background Debug Module (BDMV4) Block Description
182 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
6.4.7 Serial Interface Hardware Handshake Protocol
BDM commands that require CPU execution are ultimately treated at the MCU bus rate. Because the BDM
clock source can be asynchronously related to the bus frequency, when CLKSW = 0, it is very helpful to
provide a handshake protocol in which the host could determine when an issued command is executed by
the CPU. The alternative is to always wait the amount of time equal to the appropriate number of cycles at
the slowest possible rate the clock could be running. This sub-section will describe the hardware
handshake protocol.
The hardware handshake protocol signals to the host controller when an issued command was successfully
executed by the target. This protocol is implemented by a 16 serial clock cycle low pulse followed by a
brief speedup pulse in the BKGD pin. This pulse is generated by the target MCU when a command, issued
by the host, has been successfully executed (see Figure 6-10). This pulse is referred to as the ACK pulse.
After the ACK pulse has finished: the host can start the bit retrieval if the last issued command was a read
command, or start a new command if the last command was a write command or a control command
(BACKGROUND, GO, GO_UNTIL, or TRACE1). The ACK pulse is not issued earlier than 32 serial
clock cycles after the BDM command was issued. The end of the BDM command is assumed to be the
16th tick of the last bit. This minimum delay assures enough time for the host to perceive the ACK pulse.
Note also that, there is no upper limit for the delay between the command and the related ACK pulse,
because the command execution depends upon the CPU bus frequency, which in some cases could be very
slow compared to the serial communication rate. This protocol allows a great flexibility for the POD
designers, because it does not rely on any accurate time measurement or short response time to any event
in the serial communication.
Figure 6-10. Target Acknowledge Pulse (ACK)
NOTE
If the ACK pulse was issued by the target, the host assumes the previous
command was executed. If the CPU enters WAIT or STOP prior to
executing a hardware command, the ACK pulse will not be issued meaning
that the BDM command was not executed. After entering wait or stop mode,
the BDM command is no longer pending.
16 CYCLES
BDM CLOCK
(TARGET MCU)
TARGET
TRANSMITS
PULSE
ACK
HIGH-IMPEDANCE
BKGD PIN
MINIMUM DELAY
FROM THE BDM COMMAND
32 CYCLES
EARLIEST
START OF
NEXT BIT
SPEEDUP PULSE
16th TICK OF THE
LAST COMMAD BIT
HIGH-IMPEDANCE
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 183
Rev 01.24
Figure 6-11 shows the ACK handshake protocol in a command level timing diagram. The READ_BYTE
instruction is used as an example. First, the 8-bit instruction opcode is sent by the host, followed by the
address of the memory location to be read. The target BDM decodes the instruction. A bus cycle is grabbed
(free or stolen) by the BDM and it executes the READ_BYTE operation. Having retrieved the data, the
BDM issues an ACK pulse to the host controller, indicating that the addressed byte is ready to be retrieved.
After detecting the ACK pulse, the host initiates the byte retrieval process. Note that data is sent in the form
of a word and the host needs to determine which is the appropriate byte based on whether the address was
odd or even.
Figure 6-11. Handshake Protocol at Command Level
Differently from the normal bit transfer (where the host initiates the transmission), the serial interface ACK
handshake pulse is initiated by the target MCU by issuing a falling edge in the BKGD pin. The hardware
handshake protocol in Figure 6-10 specifies the timing when the BKGD pin is being driven, so the host
should follow this timing constraint in order to avoid the risk of an electrical conflict in the BKGD pin.
NOTE
The only place the BKGD pin can have an electrical conflict is when one
side is driving low and the other side is issuing a speedup pulse (high). Other
“highs” are pulled rather than driven. However, at low rates the time of the
speedup pulse can become lengthy and so the potential conflict time
becomes longer as well.
The ACK handshake protocol does not support nested ACK pulses. If a BDM command is not
acknowledge by an ACK pulse, the host needs to abort the pending command first in order to be able to
issue a new BDM command. When the CPU enters WAIT or STOP while the host issues a command that
requires CPU execution (e.g., WRITE_BYTE), the target discards the incoming command due to the
WAIT or STOP being detected. Therefore, the command is not acknowledged by the target, which means
that the ACK pulse will not be issued in this case. After a certain time the host should decide to abort the
ACK sequence in order to be free to issue a new command. Therefore, the protocol should provide a
mechanism in which a command, and therefore a pending ACK, could be aborted.
NOTE
Differently from a regular BDM command, the ACK pulse does not provide
a time out. This means that in the case of a WAIT or STOP instruction being
executed, the ACK would be prevented from being issued. If not aborted, the
ACK would remain pending indefinitely. See the handshake abort procedure
described in Section 6.4.8, “Hardware Handshake Abort Procedure.”
READ_BYTE
BDM ISSUES THE
BKGD PIN BYTE ADDRESS
BDM EXECUTES THE
READ_BYTE COMMAND
HOST TARGET
HOSTTARGET
BDM DECODES
THE COMMAND
ACK PULSE (OUT OF SCALE)
HOST TARGET
(2) BYTES ARE
RETRIEVED
NEW BDM
COMMAND
Chapter 6 Background Debug Module (BDMV4) Block Description
184 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
6.4.8 Hardware Handshake Abort Procedure
The abort procedure is based on the SYNC command. In order to abort a command, which had not issued
the corresponding ACK pulse, the host controller should generate a low pulse in the BKGD pin by driving
it low for at least 128 serial clock cycles and then driving it high for one serial clock cycle, providing a
speedup pulse. By detecting this long low pulse in the BKGD pin, the target executes the SYNC protocol,
see Section 6.4.9, “SYNC — Request Timed Reference Pulse,” and assumes that the pending command
and therefore the related ACK pulse, are being aborted. Therefore, after the SYNC protocol has been
completed the host is free to issue new BDM commands.
Although it is not recommended, the host could abort a pending BDM command by issuing a low pulse in
the BKGD pin shorter than 128 serial clock cycles, which will not be interpreted as the SYNC command.
The ACK is actually aborted when a falling edge is perceived by the target in the BKGD pin. The short
abort pulse should have at least 4 clock cycles keeping the BKGD pin low, in order to allow the falling
edge to be detected by the target. In this case, the target will not execute the SYNC protocol but the pending
command will be aborted along with the ACK pulse. The potential problem with this abort procedure is
when there is a conflict between the ACK pulse and the short abort pulse. In this case, the target may not
perceive the abort pulse. The worst case is when the pending command is a read command (i.e.,
READ_BYTE). If the abort pulse is not perceived by the target the host will attempt to send a new
command after the abort pulse was issued, while the target expects the host to retrieve the accessed
memory byte. In this case, host and target will run out of synchronism. However, if the command to be
aborted is not a read command the short abort pulse could be used. After a command is aborted the target
assumes the next falling edge, after the abort pulse, is the first bit of a new BDM command.
NOTE
The details about the short abort pulse are being provided only as a reference
for the reader to better understand the BDM internal behavior. It is not
recommended that this procedure be used in a real application.
Because the host knows the target serial clock frequency, the SYNC command (used to abort a command)
does not need to consider the lower possible target frequency. In this case, the host could issue a SYNC
very close to the 128 serial clock cycles length. Providing a small overhead on the pulse length in order to
assure the SYNC pulse will not be misinterpreted by the target. See Section 6.4.9, “SYNC — Request
Timed Reference Pulse.”
Figure 6-12 shows a SYNC command being issued after a READ_BYTE, which aborts the READ_BYTE
command. Note that, after the command is aborted a new command could be issued by the host computer.
NOTE
Figure 6-12 does not represent the signals in a true timing scale
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 185
Rev 01.24
Figure 6-12. ACK Abort Procedure at the Command Level
Figure 6-13 shows a conflict between the ACK pulse and the SYNC request pulse. This conflict could
occur if a POD device is connected to the target BKGD pin and the target is already in debug active mode.
Consider that the target CPU is executing a pending BDM command at the exact moment the POD is being
connected to the BKGD pin. In this case, an ACK pulse is issued along with the SYNC command. In this
case, there is an electrical conflict between the ACK speedup pulse and the SYNC pulse. Because this is
not a probable situation, the protocol does not prevent this conflict from happening.
Figure 6-13. ACK Pulse and SYNC Request Conflict
NOTE
This information is being provided so that the MCU integrator will be aware
that such a conflict could eventually occur.
The hardware handshake protocol is enabled by the ACK_ENABLE and disabled by the ACK_DISABLE
BDM commands. This provides backwards compatibility with the existing POD devices which are not
able to execute the hardware handshake protocol. It also allows for new POD devices, that support the
hardware handshake protocol, to freely communicate with the target device. If desired, without the need
for waiting for the ACK pulse.
READ_BYTE READ_STATUSBKGD PIN MEMORY ADDRESS NEW BDM COMMAND
NEW BDM COMMAND
HOST TARGET HOST TARGET HOST TARGET
SYNC RESPONSE
FROM THE TARGET
(OUT OF SCALE)
BDM DECODE
AND STARTS TO EXECUTES
THE READ_BYTE CMD
READ_BYTE CMD IS ABORTED
BY THE SYNC REQUEST
(OUT OF SCALE)
BDM CLOCK
(TARGET MCU)
TARGET MCU
DRIVES TO
BKGD PIN
BKGD PIN
16 CYCLES
SPEEDUP PULSE
HIGH-IMPEDANCE
HOST
DRIVES SYNC
TO BKGD PIN
ACK PULSE
HOST SYNC REQUEST PULSE
AT LEAST 128 CYCLES
ELECTRICAL CONFLICT
HOST AND
TARGET DRIVE
TO BKGD PIN
Chapter 6 Background Debug Module (BDMV4) Block Description
186 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The commands are described as follows:
• ACK_ENABLE — enables the hardware handshake protocol. The target will issue the ACK pulse
when a CPU command is executed by the CPU. The ACK_ENABLE command itself also has the
ACK pulse as a response.
• ACK_DISABLE — disables the ACK pulse protocol. In this case, the host needs to use the worst
case delay time at the appropriate places in the protocol.
The default state of the BDM after reset is hardware handshake protocol disabled.
All the read commands will ACK (if enabled) when the data bus cycle has completed and the data is then
ready for reading out by the BKGD serial pin. All the write commands will ACK (if enabled) after the data
has been received by the BDM through the BKGD serial pin and when the data bus cycle is complete. See
Section 6.4.3, “BDM Hardware Commands,” and Section 6.4.4, “Standard BDM Firmware Commands,”
for more information on the BDM commands.
The ACK_ENABLE sends an ACK pulse when the command has been completed. This feature could be
used by the host to evaluate if the target supports the hardware handshake protocol. If an ACK pulse is
issued in response to this command, the host knows that the target supports the hardware handshake
protocol. If the target does not support the hardware handshake protocol the ACK pulse is not issued. In
this case, the ACK_ENABLE command is ignored by the target because it is not recognized as a valid
command.
The BACKGROUND command will issue an ACK pulse when the CPU changes from normal to
background mode. The ACK pulse related to this command could be aborted using the SYNC command.
The GO command will issue an ACK pulse when the CPU exits from background mode. The ACK pulse
related to this command could be aborted using the SYNC command.
The GO_UNTIL command is equivalent to a GO command with exception that the ACK pulse, in this
case, is issued when the CPU enters into background mode. This command is an alternative to the GO
command and should be used when the host wants to trace if a breakpoint match occurs and causes the
CPU to enter active background mode. Note that the ACK is issued whenever the CPU enters BDM, which
could be caused by a breakpoint match or by a BGND instruction being executed. The ACK pulse related
to this command could be aborted using the SYNC command.
The TRACE1 command has the related ACK pulse issued when the CPU enters background active mode
after one instruction of the application program is executed. The ACK pulse related to this command could
be aborted using the SYNC command.
The TAGGO command will not issue an ACK pulse because this would interfere with the tagging function
shared on the same pin.
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 187
Rev 01.24
6.4.9 SYNC — Request Timed Reference Pulse
The SYNC command is unlike other BDM commands because the host does not necessarily know the
correct communication speed to use for BDM communications until after it has analyzed the response to
the SYNC command. To issue a SYNC command, the host should perform the following steps:
1. Drive the BKGD pin low for at least 128 cycles at the lowest possible BDM serial communication
frequency (the lowest serial communication frequency is determined by the crystal oscillator or the
clock chosen by CLKSW.)
2. Drive BKGD high for a brief speedup pulse to get a fast rise time (this speedup pulse is typically
one cycle of the host clock.)
3. Remove all drive to the BKGD pin so it reverts to high impedance.
4. Listen to the BKGD pin for the sync response pulse.
Upon detecting the SYNC request from the host, the target performs the following steps:
1. Discards any incomplete command received or bit retrieved.
2. Waits for BKGD to return to a logic 1.
3. Delays 16 cycles to allow the host to stop driving the high speedup pulse.
4. Drives BKGD low for 128 cycles at the current BDM serial communication frequency.
5. Drives a one-cycle high speedup pulse to force a fast rise time on BKGD.
6. Removes all drive to the BKGD pin so it reverts to high impedance.
The host measures the low time of this 128 cycle SYNC response pulse and determines the correct speed
for subsequent BDM communications. Typically, the host can determine the correct communication speed
within a few percent of the actual target speed and the communication protocol can easily tolerate speed
errors of several percent.
As soon as the SYNC request is detected by the target, any partially received command or bit retrieved is
discarded. This is referred to as a soft-reset, equivalent to a time-out in the serial communication. After the
SYNC response, the target will consider the next falling edge (issued by the host) as the start of a new
BDM command or the start of new SYNC request.
Another use of the SYNC command pulse is to abort a pending ACK pulse. The behavior is exactly the
same as in a regular SYNC command. Note that one of the possible causes for a command to not be
acknowledged by the target is a host-target synchronization problem. In this case, the command may not
have been understood by the target and so an ACK response pulse will not be issued.
6.4.10 Instruction Tracing
When a TRACE1 command is issued to the BDM in active BDM, the CPU exits the standard BDM
firmware and executes a single instruction in the user code. As soon as this has occurred, the CPU is forced
to return to the standard BDM firmware and the BDM is active and ready to receive a new command. If
the TRACE1 command is issued again, the next user instruction will be executed. This facilitates stepping
or tracing through the user code one instruction at a time.
Chapter 6 Background Debug Module (BDMV4) Block Description
188 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
If an interrupt is pending when a TRACE1 command is issued, the interrupt stacking operation occurs but
no user instruction is executed. Upon return to standard BDM firmware execution, the program counter
points to the first instruction in the interrupt service routine.
6.4.11 Instruction Tagging
The instruction queue and cycle-by-cycle CPU activity are reconstructible in real time or from trace history
that is captured by a logic analyzer. However, the reconstructed queue cannot be used to stop the CPU at
a specific instruction. This is because execution already has begun by the time an operation is visible
outside the system. A separate instruction tagging mechanism is provided for this purpose.
The tag follows program information as it advances through the instruction queue. When a tagged
instruction reaches the head of the queue, the CPU enters active BDM rather than executing the instruction.
NOTE
Tagging is disabled when BDM becomes active and BDM serial commands
are not processed while tagging is active.
Executing the BDM TAGGO command configures two system pins for tagging. The TAGLO signal shares
a pin with the LSTRB signal, and the TAGHI signal shares a pin with the BKGD signal.
Table 6-7 shows the functions of the two tagging pins. The pins operate independently, that is the state of
one pin does not affect the function of the other. The presence of logic level 0 on either pin at the fall of
the external clock (ECLK) performs the indicated function. High tagging is allowed in all modes. Low
tagging is allowed only when low strobe is enabled (LSTRB is allowed only in wide expanded modes and
emulation expanded narrow mode).
6.4.12 Serial Communication Time-Out
The host initiates a host-to-target serial transmission by generating a falling edge on the BKGD pin. If
BKGD is kept low for more than 128 target clock cycles, the target understands that a SYNC command
was issued. In this case, the target will keep waiting for a rising edge on BKGD in order to answer the
SYNC request pulse. If the rising edge is not detected, the target will keep waiting forever without any
time-out limit.
Consider now the case where the host returns BKGD to logic one before 128 cycles. This is interpreted as
a valid bit transmission, and not as a SYNC request. The target will keep waiting for another falling edge
marking the start of a new bit. If, however, a new falling edge is not detected by the target within 512 clock
cycles since the last falling edge, a time-out occurs and the current command is discarded without affecting
memory or the operating mode of the MCU. This is referred to as a soft-reset.
Table 6-7. Tag Pin Function
TAGHI TAGLO Tag
1 1 No tag
1 0 Low byte
0 1 High byte
0 0 Both bytes
Chapter 6 Background Debug Module (BDMV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 189
Rev 01.24
If a read command is issued but the data is not retrieved within 512 serial clock cycles, a soft-reset will
occur causing the command to be disregarded. The data is not available for retrieval after the time-out has
occurred. This is the expected behavior if the handshake protocol is not enabled. However, consider the
behavior where the BDC is running in a frequency much greater than the CPU frequency. In this case, the
command could time out before the data is ready to be retrieved. In order to allow the data to be retrieved
even with a large clock frequency mismatch (between BDC and CPU) when the hardware handshake
protocol is enabled, the time out between a read command and the data retrieval is disabled. Therefore, the
host could wait for more then 512 serial clock cycles and continue to be able to retrieve the data from an
issued read command. However, as soon as the handshake pulse (ACK pulse) is issued, the time-out feature
is re-activated, meaning that the target will time out after 512 clock cycles. Therefore, the host needs to
retrieve the data within a 512 serial clock cycles time frame after the ACK pulse had been issued. After
that period, the read command is discarded and the data is no longer available for retrieval. Any falling
edge of the BKGD pin after the time-out period is considered to be a new command or a SYNC request.
Note that whenever a partially issued command, or partially retrieved data, has occurred the time out in the
serial communication is active. This means that if a time frame higher than 512 serial clock cycles is
observed between two consecutive negative edges and the command being issued or data being retrieved
is not complete, a soft-reset will occur causing the partially received command or data retrieved to be
disregarded. The next falling edge of the BKGD pin, after a soft-reset has occurred, is considered by the
target as the start of a new BDM command, or the start of a SYNC request pulse.
6.4.13 Operation in Wait Mode
The BDM cannot be used in wait mode if the system disables the clocks to the BDM.
There is a clearing mechanism associated with the WAIT instruction when the clocks to the BDM (CPU
core platform) are disabled. As the clocks restart from wait mode, the BDM receives a soft reset (clearing
any command in progress) and the ACK function will be disabled. This is a change from previous BDM
modules.
6.4.14 Operation in Stop Mode
The BDM is completely shutdown in stop mode.
There is a clearing mechanism associated with the STOP instruction. STOP must be enabled and the part
must go into stop mode for this to occur. As the clocks restart from stop mode, the BDM receives a soft
reset (clearing any command in progress) and the ACK function will be disabled. This is a change from
previous BDM modules.
Chapter 6 Background Debug Module (BDMV4) Block Description
190 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 191
Rev 01.24
Chapter 7
Debug Module (DBGV1) Block Description
7.1 Introduction
This section describes the functionality of the debug (DBG) sub-block of the HCS12 core platform.
The DBG module is designed to be fully compatible with the existing BKP_HCS12_A module (BKP
mode) and furthermore provides an on-chip trace buffer with flexible triggering capability (DBG mode).
The DBG module provides for non-intrusive debug of application software. The DBG module is optimized
for the HCS12 16-bit architecture.
7.1.1 Features
The DBG module in BKP mode includes these distinctive features:
• Full or dual breakpoint mode
— Compare on address and data (full)
— Compare on either of two addresses (dual)
• BDM or SWI breakpoint
— Enter BDM on breakpoint (BDM)
— Execute SWI on breakpoint (SWI)
• Tagged or forced breakpoint
— Break just before a specific instruction will begin execution (TAG)
— Break on the first instruction boundary after a match occurs (Force)
• Single, range, or page address compares
— Compare on address (single)
— Compare on address 256 byte (range)
— Compare on any 16K page (page)
• At forced breakpoints compare address on read or write
• High and/or low byte data compares
• Comparator C can provide an additional tag or force breakpoint (enhancement for BKP mode)
Chapter 7 Debug Module (DBGV1) Block Description
192 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The DBG in DBG mode includes these distinctive features:
• Three comparators (A, B, and C)
— Dual mode, comparators A and B used to compare addresses
— Full mode, comparator A compares address and comparator B compares data
— Can be used as trigger and/or breakpoint
— Comparator C used in LOOP1 capture mode or as additional breakpoint
• Four capture modes
— Normal mode, change-of-flow information is captured based on trigger specification
— Loop1 mode, comparator C is dynamically updated to prevent redundant change-of-flow
storage.
— Detail mode, address and data for all cycles except program fetch (P) and free (f) cycles are
stored in trace buffer
— Profile mode, last instruction address executed by CPU is returned when trace buffer address is
read
• Two types of breakpoint or debug triggers
— Break just before a specific instruction will begin execution (tag)
— Break on the first instruction boundary after a match occurs (force)
• BDM or SWI breakpoint
— Enter BDM on breakpoint (BDM)
— Execute SWI on breakpoint (SWI)
• Nine trigger modes for comparators A and B
—A
— A or B
— A then B
— A and B, where B is data (full mode)
— A and not B, where B is data (full mode)
— Event only B, store data
— A then event only B, store data
— Inside range, A ≤ address ≤B
— Outside range, address < Α or address > B
• Comparator C provides an additional tag or force breakpoint when capture mode is not configured
in LOOP1 mode.
• Sixty-four word (16 bits wide) trace buffer for storing change-of-flow information, event only data
and other bus information.
— Source address of taken conditional branches (long, short, bit-conditional, and loop constructs)
— Destination address of indexed JMP, JSR, and CALL instruction.
— Destination address of RTI, RTS, and RTC instructions
— Vector address of interrupts, except for SWI and BDM vectors
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 193
Rev 01.24
— Data associated with event B trigger modes
— Detail report mode stores address and data for all cycles except program (P) and free (f) cycles
— Current instruction address when in profiling mode
— BGND is not considered a change-of-flow (cof) by the debugger
7.1.2 Modes of Operation
There are two main modes of operation: breakpoint mode and debug mode. Each one is mutually exclusive
of the other and selected via a software programmable control bit.
In the breakpoint mode there are two sub-modes of operation:
• Dual address mode, where a match on either of two addresses will cause the system to enter
background debug mode (BDM) or initiate a software interrupt (SWI).
• Full breakpoint mode, where a match on address and data will cause the system to enter
background debug mode (BDM) or initiate a software interrupt (SWI).
In debug mode, there are several sub-modes of operation.
• Trigger modes
There are many ways to create a logical trigger. The trigger can be used to capture bus information
either starting from the trigger or ending at the trigger. Types of triggers (A and B are registers):
— A only
— A or B
— A then B
— Event only B (data capture)
— A then event only B (data capture)
— A and B, full mode
— A and not B, full mode
— Inside range
— Outside range
• Capture modes
There are several capture modes. These determine which bus information is saved and which is
ignored.
— Normal: save change-of-flow program fetches
— Loop1: save change-of-flow program fetches, ignoring duplicates
— Detail: save all bus operations except program and free cycles
— Profile: poll target from external device
7.1.3 Block Diagram
Figure 7-1 is a block diagram of this module in breakpoint mode. Figure 7-2 is a block diagram of this
module in debug mode.
Chapter 7 Debug Module (DBGV1) Block Description
194 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 7-1. DBG Block Diagram in BKP Mode
COMPARATOR
COMPARE BLOCK
REGISTER BLOCK
COMPARATOR
COMPARATOR
COMPARATOR
COMPARATOR
COMPARATOR
EXPANSION ADDRESSES
EXPANSION ADDRESSES
ADDRESS HIGH
ADDRESS LOW
DATA HIGH
DATA LOW
ADDRESS HIGH
ADDRESS LOW
COMPARATOR
COMPARATOR
READ DATA HIGH
READ DATA LOW
. . . . . . . . . . . .
CLOCKS AND BKP CONTROL
CONTROL SIGNALS SIGNALS
CONTROL BLOCK
BREAKPOINT MODES
AND GENERATION OF SWI,
FORCE BDM, AND TAGS
EXPANSION ADDRESS
ADDRESS
WRITE DATA
READ DATA
READ/WRITE
CONTROL
CONTROL BITS
CONTROL SIGNALS
RESULTS SIGNALS
BKP0H
BKP0L
BKP0X
BKPCT0
BKP1X
BKPCT1
BKP1L
BKP1H
WRITE
BKP READ
DATA BUS
DATA BUS
DATA/ADDRESS
HIGH MUX
DATA/ADDRESS
LOW MUX
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 195
Rev 01.24
Figure 7-2. DBG Block Diagram in DBG Mode
7.2 External Signal Description
The DBG sub-module relies on the external bus interface (generally the MEBI) when the DBG is matching
on the external bus.
The tag pins in Table 7-1 (part of the MEBI) may also be a part of the breakpoint operation.
Table 7-1. External System Pins Associated with DBG and MEBI
Pin Name Pin Functions Description
BKGD/MODC/
TAGHI
TAGHI When instruction tagging is on, a 0 at the falling edge of E tags the high half of the
instruction word being read into the instruction queue.
PE3/LSTRB/ TAGLO TAGLO In expanded wide mode or emulation narrow modes, when instruction tagging is on
and low strobe is enabled, a 0 at the falling edge of E tags the low half of the
instruction word being read into the instruction queue.
TAG
FORCE
ADDRESS BUS
MATCH_A
CONTROL
READ DATA BUS
READ/WRITE
STORE
MCU IN BDM
M
U
X
POINTER
REGISTER
MATCH_B
M
U
X
EVENT ONLY
WRITE DATA BUS
TRACE BUFFER
DBG READ DATA BUS
DBG MODE ENABLE
M
U
X
WRITE DATA BUS
READ DATA BUS
READ/WRITE
MATCH_C
LOOP1
DETAIL
M
U
X
PROFILE CAPTURE MODE
CPU PROGRAM COUNTER
CONTROL
COMPARATOR A
ADDRESS/DATA/CONTROL
COMPARATOR B
COMPARATOR C
REGISTERS
TRACER
BUFFER
CONTROL
LOGIC
CHANGE-OF-FLOW
INDICATORS
OR PROFILING DATA
64 x 16 BIT
WORD
TRACE
BUFFER
PROFILE
CAPTURE
REGISTER
LAST
INSTRUCTION
ADDRESS
BUS CLOCK
INSTRUCTION
LAST CYCLE
Chapter 7 Debug Module (DBGV1) Block Description
196 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.3 Memory Map and Register Definition
A summary of the registers associated with the DBG sub-block is shown in Figure 7-3. Detailed
descriptions of the registers and bits are given in the subsections that follow.
7.3.1 Module Memory Map
7.3.2 Register Descriptions
This section consists of the DBG register descriptions in address order. Most of the register bits can be
written to in either BKP or DBG mode, although they may not have any effect in one of the modes.
However, the only bits in the DBG module that can be written while the debugger is armed (ARM = 1) are
DBGEN and ARM
Table 7-2. DBGV1 Memory Map
Address
Offset Use Access
0x0020 Debug Control Register (DBGC1) R/W
0x0021 Debug Status and Control Register (DBGSC) R/W
0x0022 Debug Trace Buffer Register High (DBGTBH) R
0x0023 Debug Trace Buffer Register Low (DBGTBL) R
0x0024 Debug Count Register (DBGCNT) R
0x0025 Debug Comparator C Extended Register (DBGCCX) R/W
0x0026 Debug Comparator C Register High (DBGCCH) R/W
0x0027 Debug Comparator C Register Low (DBGCCL) R/W
0x0028 Debug Control Register 2 (DBGC2) / (BKPCT0) R/W
0x0029 Debug Control Register 3 (DBGC3) / (BKPCT1) R/W
0x002A Debug Comparator A Extended Register (DBGCAX) / (/BKP0X) R/W
0x002B Debug Comparator A Register High (DBGCAH) / (BKP0H) R/W
0x002C Debug Comparator A Register Low (DBGCAL) / (BKP0L) R/W
0x002D Debug Comparator B Extended Register (DBGCBX) / (BKP1X) R/W
0x002E Debug Comparator B Register High (DBGCBH) / (BKP1H) R/W
0x002F Debug Comparator B Register Low (DBGCBL) / (BKP1L) R/W
Name(1) Bit 7 6 5 4 3 2 1 Bit 0
0x0020
DBGC1
RDBGEN ARM TRGSEL BEGIN DBGBRK 0CAPMOD
W
0x0021
DBGSC
RAF BF CF 0 TRG
W
= Unimplemented or Reserved
Figure 7-3. DBG Register Summary
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 197
Rev 01.24
0x0022
DBGTBH
R Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
W
0x0023
DBGTBL
R Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
0x0024
DBGCNT
R TBF 0 CNT
W
0x0025
DBGCCX((2))
RPAGSEL EXTCMP
W
0x0026
DBGCCH(2)
RBit 15 14 13 12 11 10 9 Bit 8
W
0x0027
DBGCCL(2)
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0028
DBGC2
BKPCT0
R
BKABEN FULL BDM TAGAB BKCEN TAGC RWCEN RWC
W
0x0029
DBGC3
BKPCT1
R
BKAMBH BKAMBL BKBMBH BKBMBL RWAEN RWA RWBEN RWB
W
0x002A
DBGCAX
BKP0X
R
PAGSEL EXTCMP
W
0x002B
DBGCAH
BKP0H
R
Bit 15 14 13 12 11 10 9 Bit 8
W
0x002C
DBGCAL
BKP0L
R
Bit 7 6 5 4 3 2 1 Bit 0
W
0x002D
DBGCBX
BKP1X
R
PAGSEL EXTCMP
W
0x002E
DBGCBH
BKP1H
R
Bit 15 14 13 12 11 10 9 Bit 8
W
0x002F
DBGCBL
BKP1L
R
Bit 7 6 5 4 3 2 1 Bit 0
W
Name(1) Bit 7 6 5 4 3 2 1 Bit 0
= Unimplemented or Reserved
Figure 7-3. DBG Register Summary (continued)
Chapter 7 Debug Module (DBGV1) Block Description
198 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.3.2.1 Debug Control Register 1 (DBGC1)
NOTE
All bits are used in DBG mode only.
NOTE
This register cannot be written if BKP mode is enabled (BKABEN in
DBGC2 is set).
1. The DBG module is designed for backwards compatibility to existing BKP modules. Register and bit names have changed from
the BKP module. This column shows the DBG register name, as well as the BKP register name for reference.
2. Comparator C can be used to enhance the BKP mode by providing a third breakpoint.
Module Base + 0x0020
Starting address location affected by INITRG register setting.
76543210
R
DBGEN ARM TRGSEL BEGIN DBGBRK
0
CAPMOD
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 7-4. Debug Control Register (DBGC1)
Table 7-3. DBGC1 Field Descriptions
Field Description
7
DBGEN
DBG Mode Enable Bit — The DBGEN bit enables the DBG module for use in DBG mode. This bit cannot be
set if the MCU is in secure mode.
0 DBG mode disabled
1 DBG mode enabled
6
ARM
Arm Bit — The ARM bit controls whether the debugger is comparing and storing data in the trace buffer. See
Section 7.4.2.4, “Arming the DBG Module,” for more information.
0 Debugger unarmed
1 Debugger armed
Note: This bit cannot be set if the DBGEN bit is not also being set at the same time. For example, a write of 01
to DBGEN[7:6] will be interpreted as a write of 00.
5
TRGSEL
Trigger Selection Bit — The TRGSEL bit controls the triggering condition for comparators A and B in DBG
mode. It serves essentially the same function as the TAGAB bit in the DBGC2 register does in BKP mode. See
Section 7.4.2.1.2, “Trigger Selection,” for more information. TRGSEL may also determine the type of breakpoint
based on comparator A and B if enabled in DBG mode (DBGBRK = 1). Please refer to Section 7.4.3.1,
“Breakpoint Based on Comparator A and B.”
0 Trigger on any compare address match
1 Trigger before opcode at compare address gets executed (tagged-type)
4
BEGIN
Begin/End Trigger Bit — The BEGIN bit controls whether the trigger begins or ends storing of data in the trace
buffer. See Section 7.4.2.8.1, “Storing with Begin-Trigger,” and Section 7.4.2.8.2, “Storing with End-Trigger,” for
more details.
0 Trigger at end of stored data
1 Trigger before storing data
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 199
Rev 01.24
3
DBGBRK
DBG Breakpoint Enable Bit — The DBGBRK bit controls whether the debugger will request a breakpoint based
on comparator A and B to the CPU upon completion of a tracing session. Please refer to Section 7.4.3,
“Breakpoints,” for further details.
0 CPU break request not enabled
1 CPU break request enabled
1:0
CAPMOD
Capture Mode Field — See Table 7-4 for capture mode field definitions. In LOOP1 mode, the debugger will
automatically inhibit redundant entries into capture memory. In detail mode, the debugger is storing address and
data for all cycles except program fetch (P) and free (f) cycles. In profile mode, the debugger is returning the
address of the last instruction executed by the CPU on each access of trace buffer address. Refer to
Section 7.4.2.6, “Capture Modes,” for more information.
Table 7-4. CAPMOD Encoding
CAPMOD Description
00 Normal
01 LOOP1
10 DETAIL
11 PROFILE
Table 7-3. DBGC1 Field Descriptions (continued)
Field Description
Chapter 7 Debug Module (DBGV1) Block Description
200 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.3.2.2 Debug Status and Control Register (DBGSC)
Module Base + 0x0021
Starting address location affected by INITRG register setting.
76543210
RAF BF CF 0
TRG
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 7-5. Debug Status and Control Register (DBGSC)
Table 7-5. DBGSC Field Descriptions
Field Description
7
AF
Trigger A Match Flag — The AF bit indicates if trigger A match condition was met since arming. This bit is
cleared when ARM in DBGC1 is written to a 1 or on any write to this register.
0 Trigger A did not match
1 Trigger A match
6
BF
Trigger B Match Flag — The BF bit indicates if trigger B match condition was met since arming.This bit is
cleared when ARM in DBGC1 is written to a 1 or on any write to this register.
0 Trigger B did not match
1 Trigger B match
5
CF
Comparator C Match Flag — The CF bit indicates if comparator C match condition was met since arming.This
bit is cleared when ARM in DBGC1 is written to a 1 or on any write to this register.
0 Comparator C did not match
1 Comparator C match
3:0
TRG
Trigger Mode Bits — The TRG bits select the trigger mode of the DBG module as shown Table 7-6. See
Section 7.4.2.5, “Trigger Modes,” for more detail.
Table 7-6. Trigger Mode Encoding
TRG Value Meaning
0000 A only
0001 A or B
0010 A then B
0011 Event only B
0100 A then event only B
0101 A and B (full mode)
0110 A and Not B (full mode)
0111 Inside range
1000 Outside range
1001
↓
1111
Reserved
(Defaults to A only)
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 201
Rev 01.24
7.3.2.3 Debug Trace Buffer Register (DBGTB)
Module Base + 0x0022
Starting address location affected by INITRG register setting.
15 14 13 12 11 10 9 8
R Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
W
Reset u u u uuuuu
= Unimplemented or Reserved
Figure 7-6. Debug Trace Buffer Register High (DBGTBH)
Module Base + 0x0023
Starting address location affected by INITRG register setting.
76543210
R Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
Reset u u u uuuuu
= Unimplemented or Reserved
Figure 7-7. Debug Trace Buffer Register Low (DBGTBL)
Table 7-7. DBGTB Field Descriptions
Field Description
15:0 Trace Buffer Data Bits — The trace buffer data bits contain the data of the trace buffer. This register can be read
only as a word read. Any byte reads or misaligned access of these registers will return 0 and will not cause the
trace buffer pointer to increment to the next trace buffer address. The same is true for word reads while the
debugger is armed. In addition, this register may appear to contain incorrect data if it is not read with the same
capture mode bit settings as when the trace buffer data was recorded (See Section 7.4.2.9, “Reading Data from
Trace Buffer”). Because reads will reflect the contents of the trace buffer RAM, the reset state is undefined.
Chapter 7 Debug Module (DBGV1) Block Description
202 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.3.2.4 Debug Count Register (DBGCNT)
Module Base + 0x0024
Starting address location affected by INITRG register setting.
76543210
R TBF 0 CNT
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 7-8. Debug Count Register (DBGCNT)
Table 7-8. DBGCNT Field Descriptions
Field Description
7
TBF
Trace Buffer Full — The TBF bit indicates that the trace buffer has stored 64 or more words of data since it was
last armed. If this bit is set, then all 64 words will be valid data, regardless of the value in CNT[5:0]. The TBF bit
is cleared when ARM in DBGC1 is written to a 1.
5:0
CNT
Count Value — The CNT bits indicate the number of valid data words stored in the trace buffer. Table 7-9 shows
the correlation between the CNT bits and the number of valid data words in the trace buffer. When the CNT rolls
over to 0, the TBF bit will be set and incrementing of CNT will continue if DBG is in end-trigger mode. The
DBGCNT register is cleared when ARM in DBGC1 is written to a 1.
Table 7-9. CNT Decoding Table
TBF CNT Description
0 000000 No data valid
0 000001 1 word valid
0 000010
..
..
111110
2 words valid
..
..
62 words valid
0 111111 63 words valid
1 000000 64 words valid; if BEGIN = 1, the
ARM bit will be cleared. A
breakpoint will be generated if
DBGBRK = 1
1 000001
..
..
111111
64 words valid,
oldest data has been overwritten
by most recent data
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 203
Rev 01.24
7.3.2.5 Debug Comparator C Extended Register (DBGCCX)
Module Base + 0x0025
Starting address location affected by INITRG register setting.
76543210
R
PAGSEL EXTCMP
W
Reset 0 0 0 00000
Figure 7-9. Debug Comparator C Extended Register (DBGCCX)
Table 7-10. DBGCCX Field Descriptions
Field Description
7:6
PAGSEL
Page Selector Field — In both BKP and DBG mode, PAGSEL selects the type of paging as shown in Table 7-11.
DPAGE and EPAGE are not yet implemented so the value in bit 7 will be ignored (i.e., PAGSEL values of 10 and
11 will be interpreted as values of 00 and 01, respectively).
5:0
EXTCMP
Comparator C Extended Compare Bits — The EXTCMP bits are used as comparison address bits as shown
in Table 7-11 along with the appropriate PPAGE, DPAGE, or EPAGE signal from the core.
Note: Comparator C can be used when the DBG module is configured for BKP mode. Extended addressing
comparisons for comparator C use PAGSEL and will operate differently to the way that comparator A and
B operate in BKP mode.
Table 7-11. PAGSEL Decoding(1)
1. See Figure 7-10.
PAGSEL Description EXTCMP Comment
00 Normal (64k) Not used No paged memory
01 PPAGE
(256 — 16K pages)
EXTCMP[5:0] is compared to
address bits [21:16](2)
2. Current HCS12 implementations have PPAGE limited to 6 bits. Therefore, EXTCMP[5:4] should be set to 00.
PPAGE[7:0] / XAB[21:14] becomes
address bits [21:14]1
10(3)
3. Data page (DPAGE) and Extra page (EPAGE) are reserved for implementation on devices that support paged data and extra
space.
DPAGE (reserved)
(256 — 4K pages)
EXTCMP[3:0] is compared to
address bits [19:16]
DPAGE / XAB[21:14] becomes address
bits [19:12]
112EPAGE (reserved)
(256 — 1K pages)
EXTCMP[1:0] is compared to
address bits [17:16]
EPAGE / XAB[21:14] becomes address
bits [17:10]
Chapter 7 Debug Module (DBGV1) Block Description
204 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.3.2.6 Debug Comparator C Register (DBGCC)
DBGCXX DBGCXH[15:12]
PAGSEL EXTCMP
BIT 15 BIT 14 BIT 13 BIT 12
76
0
5
0
43 2 1 BIT 0
SEE NOTE 1
PORTK/XAB XAB21 XAB20 XAB19 XAB18 XAB17 XAB16 XAB15 XAB14
PPAGE PIX7 PIX6 PIX5 PIX4 PIX3 PIX2 PIX1 PIX0
SEE NOTE 2
NOTES:
1. In BKP and DBG mode, PAGSEL selects the type of paging as shown in Table 7-11.
2. Current HCS12 implementations are limited to six PPAGE bits, PIX[5:0]. Therefore, EXTCMP[5:4] = 00.
Figure 7-10. Comparator C Extended Comparison in BKP/DBG Mode
Module Base + 0x0026
Starting address location affected by INITRG register setting.
15 14 13 12 11 10 9 8
R Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 7-11. Debug Comparator C Register High (DBGCCH)
Module Base + 0x0027
Starting address location affected by INITRG register setting.
76543210
R Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 7-12. Debug Comparator C Register Low (DBGCCL)
BKP/DBG MODE
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 205
Rev 01.24
7.3.2.7 Debug Control Register 2 (DBGC2)
Figure 7-13. Debug Control Register 2 (DBGC2)
Table 7-12. DBGCC Field Descriptions
Field Description
15:0 Comparator C Compare Bits — The comparator C compare bits control whether comparator C will compare
the address bus bits [15:0] to a logic 1 or logic 0. See Table 7-13.
0 Compare corresponding address bit to a logic 0
1 Compare corresponding address bit to a logic 1
Note: This register will be cleared automatically when the DBG module is armed in LOOP1 mode.
Table 7-13. Comparator C Compares
PAGSEL EXTCMP Compare High-Byte Compare
x0 No compare DBGCCH[7:0] = AB[15:8]
x1 EXTCMP[5:0] = XAB[21:16] DBGCCH[7:0] = XAB[15:14],AB[13:8]
Module Base + 0x0028
Starting address location affected by INITRG register setting.
76543210
R
BKABEN(1)
1. When BKABEN is set (BKP mode), all bits in DBGC2 are available. When BKABEN is cleared and DBG is used in DBG mode,
bits FULL and TAGAB have no meaning.
FULL BDM TAGAB BKCEN(2)
2. These bits can be used in BKP mode and DBG mode (when capture mode is not set in LOOP1) to provide a third breakpoint.
TAGC 2RWCEN2RWC2
W
Reset 0 0 0 00000
Table 7-14. DBGC2 Field Descriptions
Field Description
7
BKABEN
Breakpoint Using Comparator A and B Enable — This bit enables the breakpoint capability using comparator
A and B, when set (BKP mode) the DBGEN bit in DBGC1 cannot be set.
0 Breakpoint module off
1 Breakpoint module on
6
FULL
Full Breakpoint Mode Enable — This bit controls whether the breakpoint module is in dual mode or full mode.
In full mode, comparator A is used to match address and comparator B is used to match data. See
Section 7.4.1.2, “Full Breakpoint Mode,” for more details.
0 Dual address mode enabled
1 Full breakpoint mode enabled
5
BDM
Background Debug Mode Enable — This bit determines if the breakpoint causes the system to enter
background debug mode (BDM) or initiate a software interrupt (SWI).
0 Go to software interrupt on a break request
1 Go to BDM on a break request
Chapter 7 Debug Module (DBGV1) Block Description
206 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.3.2.8 Debug Control Register 3 (DBGC3)
Figure 7-14. Debug Control Register 3 (DBGC3)
4
TAGAB
Comparator A/B Tag Select — This bit controls whether the breakpoint will cause a break on the next instruction
boundary (force) or on a match that will be an executable opcode (tagged). Non-executed opcodes cannot cause
a tagged breakpoint.
0 On match, break at the next instruction boundary (force)
1 On match, break if/when the instruction is about to be executed (tagged)
3
BKCEN
Breakpoint Comparator C Enable Bit — This bit enables the breakpoint capability using comparator C.
0 Comparator C disabled for breakpoint
1 Comparator C enabled for breakpoint
Note: This bit will be cleared automatically when the DBG module is armed in loop1 mode.
2
TAGC
Comparator C Tag Select — This bit controls whether the breakpoint will cause a break on the next instruction
boundary (force) or on a match that will be an executable opcode (tagged). Non-executed opcodes cannot cause
a tagged breakpoint.
0 On match, break at the next instruction boundary (force)
1 On match, break if/when the instruction is about to be executed (tagged)
1
RWCEN
Read/Write Comparator C Enable Bit — The RWCEN bit controls whether read or write comparison is enabled
for comparator C. RWCEN is not useful for tagged breakpoints.
0 Read/Write is not used in comparison
1 Read/Write is used in comparison
0
RWC
Read/Write Comparator C Value Bit — The RWC bit controls whether read or write is used in compare for
comparator C. The RWC bit is not used if RWCEN = 0.
0 Write cycle will be matched
1 Read cycle will be matched
Module Base + 0x0029
Starting address location affected by INITRG register setting.
76543210
R
BKAMBH(1)
1. In DBG mode, BKAMBH:BKAMBL has no meaning and are forced to 0’s.
BKAMBL1BKBMBH(2)
2. In DBG mode, BKBMBH:BKBMBL are used in full mode to qualify data.
BKBMBL2RWAEN RWA RWBEN RWB
W
Reset 0 0 0 00000
Table 7-14. DBGC2 Field Descriptions (continued)
Field Description
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 207
Rev 01.24
Table 7-15. DBGC3 Field Descriptions
Field Description
7:6
BKAMB[H:L]
Breakpoint Mask High Byte for First Address — In dual or full mode, these bits may be used to mask (disable)
the comparison of the high and/or low bytes of the first address breakpoint. The functionality is as given in
Table 7-16.
The x:0 case is for a full address compare. When a program page is selected, the full address compare will be
based on bits for a 20-bit compare. The registers used for the compare are {DBGCAX[5:0], DBGCAH[5:0],
DBGCAL[7:0]}, where DBGAX[5:0] corresponds to PPAGE[5:0] or extended address bits [19:14] and CPU
address [13:0]. When a program page is not selected, the full address compare will be based on bits for a 16-bit
compare. The registers used for the compare are {DBGCAH[7:0], DBGCAL[7:0]} which corresponds to CPU
address [15:0].
Note: This extended address compare scheme causes an aliasing problem in BKP mode in which several
physical addresses may match with a single logical address. This problem may be avoided by using DBG
mode to generate breakpoints.
The 1:0 case is not sensible because it would ignore the high order address and compare the low order and
expansion addresses. Logic forces this case to compare all address lines (effectively ignoring the BKAMBH
control bit).
The 1:1 case is useful for triggering a breakpoint on any access to a particular expansion page. This only makes
sense if a program page is being accessed so that the breakpoint trigger will occur only if DBGCAX compares.
5:4
BKBMB[H:L]
Breakpoint Mask High Byte and Low Byte of Data (Second Address) — In dual mode, these bits may be
used to mask (disable) the comparison of the high and/or low bytes of the second address breakpoint. The
functionality is as given in Table 7-17.
The x:0 case is for a full address compare. When a program page is selected, the full address compare will be
based on bits for a 20-bit compare. The registers used for the compare are {DBGCBX[5:0], DBGCBH[5:0],
DBGCBL[7:0]} where DBGCBX[5:0] corresponds to PPAGE[5:0] or extended address bits [19:14] and CPU
address [13:0]. When a program page is not selected, the full address compare will be based on bits for a 16-bit
compare. The registers used for the compare are {DBGCBH[7:0], DBGCBL[7:0]} which corresponds to CPU
address [15:0].
Note: This extended address compare scheme causes an aliasing problem in BKP mode in which several
physical addresses may match with a single logical address. This problem may be avoided by using DBG
mode to generate breakpoints.
The 1:0 case is not sensible because it would ignore the high order address and compare the low order and
expansion addresses. Logic forces this case to compare all address lines (effectively ignoring the BKBMBH
control bit).
The 1:1 case is useful for triggering a breakpoint on any access to a particular expansion page. This only makes
sense if a program page is being accessed so that the breakpoint trigger will occur only if DBGCBX compares.
In full mode, these bits may be used to mask (disable) the comparison of the high and/or low bytes of the data
breakpoint. The functionality is as given in Table 7-18.
3
RWAEN
Read/Write Comparator A Enable Bit — The RWAEN bit controls whether read or write comparison is enabled
for comparator A. See Section 7.4.2.1.1, “Read or Write Comparison,” for more information. This bit is not useful
for tagged operations.
0 Read/Write is not used in comparison
1 Read/Write is used in comparison
2
RWA
Read/Write Comparator A Value Bit — The RWA bit controls whether read or write is used in compare for
comparator A. The RWA bit is not used if RWAEN = 0.
0 Write cycle will be matched
1 Read cycle will be matched
Chapter 7 Debug Module (DBGV1) Block Description
208 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1
RWBEN
Read/Write Comparator B Enable Bit — The RWBEN bit controls whether read or write comparison is enabled
for comparator B. See Section 7.4.2.1.1, “Read or Write Comparison,” for more information. This bit is not useful
for tagged operations.
0 Read/Write is not used in comparison
1 Read/Write is used in comparison
0
RWB
Read/Write Comparator B Value Bit — The RWB bit controls whether read or write is used in compare for
comparator B. The RWB bit is not used if RWBEN = 0.
0 Write cycle will be matched
1 Read cycle will be matched
Note: RWB and RWBEN are not used in full mode.
Table 7-16. Breakpoint Mask Bits for First Address
BKAMBH:BKAMBL Address Compare DBGCAX DBGCAH DBGCAL
x:0 Full address compare Yes(1)
1. If PPAGE is selected.
Ye s Ye s
0:1 256 byte address range Yes1Ye s N o
1:1 16K byte address range Yes1No No
Table 7-17. Breakpoint Mask Bits for Second Address (Dual Mode)
BKBMBH:BKBMBL Address Compare DBGCBX DBGCBH DBGCBL
x:0 Full address compare Yes(1)
1. If PPAGE is selected.
Ye s Ye s
0:1 256 byte address range Yes1Ye s N o
1:1 16K byte address range Yes1No No
Table 7-18. Breakpoint Mask Bits for Data Breakpoints (Full Mode)
BKBMBH:BKBMBL Data Compare DBGCBX DBGCBH DBGCBL
0:0 High and low byte compare No(1)
1. Expansion addresses for breakpoint B are not applicable in this mode.
Ye s Ye s
0:1 High byte No1Ye s N o
1:0 Low byte No1No Yes
1:1 No compare No1No No
Table 7-15. DBGC3 Field Descriptions (continued)
Field Description
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 209
Rev 01.24
7.3.2.9 Debug Comparator A Extended Register (DBGCAX)
Module Base + 0x002A
Starting address location affected by INITRG register setting.
76543210
R
PAGSEL EXTCMP
W
Reset 0 0 0 00000
Figure 7-15. Debug Comparator A Extended Register (DBGCAX)
Table 7-19. DBGCAX Field Descriptions
Field Description
7:6
PAGSEL
Page Selector Field — If DBGEN is set in DBGC1, then PAGSEL selects the type of paging as shown in Ta bl e 7-
20.
DPAGE and EPAGE are not yet implemented so the value in bit 7 will be ignored (i.e., PAGSEL values of 10 and
11 will be interpreted as values of 00 and 01, respectively).
In BKP mode, PAGSEL has no meaning and EXTCMP[5:0] are compared to address bits [19:14] if the address
is in the FLASH/ROM memory space.
5:0
EXTCMP
Comparator A Extended Compare Bits — The EXTCMP bits are used as comparison address bits as shown
in Table 7-20 along with the appropriate PPAGE, DPAGE, or EPAGE signal from the core.
Table 7-20. Comparator A or B Compares
Mode EXTCMP Compare High-Byte Compare
BKP(1)
1. See Figure 7-16.
Not FLASH/ROM access No compare DBGCxH[7:0] = AB[15:8]
FLASH/ROM access EXTCMP[5:0] = XAB[19:14] DBGCxH[5:0] = AB[13:8]
DBG(2)
2. See Figure 7-10 (note that while this figure provides extended comparisons for comparator C, the figure also pertains to
comparators A and B in DBG mode only).
PAGSEL = 00 No compare DBGCxH[7:0] = AB[15:8]
PAGSEL = 01 EXTCMP[5:0] = XAB[21:16] DBGCxH[7:0] = XAB[15:14], AB[13:8]
Chapter 7 Debug Module (DBGV1) Block Description
210 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.3.2.10 Debug Comparator A Register (DBGCA)
PAGSEL EXTCMP
DBGCXX 0 0 54321BIT 0
SEE NOTE 1
PORTK/XAB XAB21 XAB20 XAB19 XAB18 XAB17 XAB16 XAB15 XAB14
PPAGE PIX7 PIX6 PIX5 PIX4 PIX3 PIX2 PIX1 PIX0
SEE NOTE 2
NOTES:
1. In BKP mode, PAGSEL has no functionality. Therefore, set PAGSEL to 00 (reset state).
2. Current HCS12 implementations are limited to six PPAGE bits, PIX[5:0].
Figure 7-16. Comparators A and B Extended Comparison in BKP Mode
Module Base + 0x002B
Starting address location affected by INITRG register setting.
15 14 13 12 11 10 9 8
R
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
W
Reset 0 0 0 00000
Figure 7-17. Debug Comparator A Register High (DBGCAH)
Module Base + 0x002C
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
Reset 0 0 0 00000
Figure 7-18. Debug Comparator A Register Low (DBGCAL)
Table 7-21. DBGCA Field Descriptions
Field Description
15:0
15:0
Comparator A Compare Bits — The comparator A compare bits control whether comparator A compares the
address bus bits [15:0] to a logic 1 or logic 0. See Table 7-20.
0 Compare corresponding address bit to a logic 0
1 Compare corresponding address bit to a logic 1
BKP MODE
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 211
Rev 01.24
7.3.2.11 Debug Comparator B Extended Register (DBGCBX)
7.3.2.12 Debug Comparator B Register (DBGCB)
Module Base + 0x002D
76543210
R
PAGSEL EXTCMP
W
Reset 0 0 0 00000
Figure 7-19. Debug Comparator B Extended Register (DBGCBX)
Table 7-22. DBGCBX Field Descriptions
Field Description
7:6
PAGSEL
Page Selector Field — If DBGEN is set in DBGC1, then PAGSEL selects the type of paging as shown in Ta bl e 7-
11.
DPAGE and EPAGE are not yet implemented so the value in bit 7 will be ignored (i.e., PAGSEL values of 10 and
11 will be interpreted as values of 00 and 01, respectively.)
In BKP mode, PAGSEL has no meaning and EXTCMP[5:0] are compared to address bits [19:14] if the address
is in the FLASH/ROM memory space.
5:0
EXTCMP
Comparator B Extended Compare Bits — The EXTCMP bits are used as comparison address bits as shown
in Table 7-11 along with the appropriate PPAGE, DPAGE, or EPAGE signal from the core. Also see Table 7-20.
Module Base + 0x002E
Starting address location affected by INITRG register setting.
15 14 13 12 11 10 9 8
R
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
W
Reset 0 0 0 00000
Figure 7-20. Debug Comparator B Register High (DBGCBH)
Chapter 7 Debug Module (DBGV1) Block Description
212 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.4 Functional Description
This section provides a complete functional description of the DBG module. The DBG module can be
configured to run in either of two modes, BKP or DBG. BKP mode is enabled by setting BKABEN in
DBGC2. DBG mode is enabled by setting DBGEN in DBGC1. Setting BKABEN in DBGC2 overrides the
DBGEN in DBGC1 and prevents DBG mode. If the part is in secure mode, DBG mode cannot be enabled.
7.4.1 DBG Operating in BKP Mode
In BKP mode, the DBG will be fully backwards compatible with the existing BKP_ST12_A module. The
DBGC2 register has four additional bits that were not available on existing BKP_ST12_A modules. As
long as these bits are written to either all 1s or all 0s, they should be transparent to the user. All 1s would
enable comparator C to be used as a breakpoint, but tagging would be enabled. The match address register
would be all 0s if not modified by the user. Therefore, code executing at address 0x0000 would have to
occur before a breakpoint based on comparator C would happen.
The DBG module in BKP mode supports two modes of operation: dual address mode and full breakpoint
mode. Within each of these modes, forced or tagged breakpoint types can be used. Forced breakpoints
occur at the next instruction boundary if a match occurs and tagged breakpoints allow for breaking just
before the tagged instruction executes. The action taken upon a successful match can be to either place the
CPU in background debug mode or to initiate a software interrupt.
The breakpoint can operate in dual address mode or full breakpoint mode. Each of these modes is
discussed in the subsections below.
7.4.1.1 Dual Address Mode
When dual address mode is enabled, two address breakpoints can be set. Each breakpoint can cause the
system to enter background debug mode or to initiate a software interrupt based upon the state of BDM in
Module Base + 0x002F
Starting address location affected by INITRG register setting.
76543210
R
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
Reset 0 0 0 00000
Figure 7-21. Debug Comparator B Register Low (DBGCBL)
Table 7-23. DBGCB Field Descriptions
Field Description
15:0
15:0
Comparator B Compare Bits — The comparator B compare bits control whether comparator B compares the
address bus bits [15:0] or data bus bits [15:0] to a logic 1 or logic 0. See Table 7-20.
0 Compare corresponding address bit to a logic 0, compares to data if in Full mode
1 Compare corresponding address bit to a logic 1, compares to data if in Full mode
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 213
Rev 01.24
DBGC2 being logic 1 or logic 0, respectively. BDM requests have a higher priority than SWI requests. No
data breakpoints are allowed in this mode.
TAGAB in DBGC2 selects whether the breakpoint mode is forced or tagged. The BKxMBH:L bits in
DBGC3 select whether or not the breakpoint is matched exactly or is a range breakpoint. They also select
whether the address is matched on the high byte, low byte, both bytes, and/or memory expansion. The
RWx and RWxEN bits in DBGC3 select whether the type of bus cycle to match is a read, write, or
read/write when performing forced breakpoints.
7.4.1.2 Full Breakpoint Mode
Full breakpoint mode requires a match on address and data for a breakpoint to occur. Upon a successful
match, the system will enter background debug mode or initiate a software interrupt based upon the state
of BDM in DBGC2 being logic 1 or logic 0, respectively. BDM requests have a higher priority than SWI
requests. R/W matches are also allowed in this mode.
TAGAB in DBGC2 selects whether the breakpoint mode is forced or tagged. When TAGAB is set in
DBGC2, only addresses are compared and data is ignored. The BKAMBH:L bits in DBGC3 select
whether or not the breakpoint is matched exactly, is a range breakpoint, or is in page space. The
BKBMBH:L bits in DBGC3 select whether the data is matched on the high byte, low byte, or both bytes.
RWA and RWAEN bits in DBGC2 select whether the type of bus cycle to match is a read or a write when
performing forced breakpoints. RWB and RWBEN bits in DBGC2 are not used in full breakpoint mode.
NOTE
The full trigger mode is designed to be used for either a word access or a
byte access, but not both at the same time. Confusing trigger operation
(seemingly false triggers or no trigger) can occur if the trigger address
occurs in the user program as both byte and word accesses.
7.4.1.3 Breakpoint Priority
Breakpoint operation is first determined by the state of the BDM module. If the BDM module is already
active, meaning the CPU is executing out of BDM firmware, breakpoints are not allowed. In addition,
while executing a BDM TRACE command, tagging into BDM is not allowed. If BDM is not active, the
breakpoint will give priority to BDM requests over SWI requests. This condition applies to both forced
and tagged breakpoints.
In all cases, BDM related breakpoints will have priority over those generated by the Breakpoint sub-block.
This priority includes breakpoints enabled by the TAGLO and TAGHI external pins of the system that
interface with the BDM directly and whose signal information passes through and is used by the
breakpoint sub-block.
Chapter 7 Debug Module (DBGV1) Block Description
214 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
NOTE
BDM should not be entered from a breakpoint unless the ENABLE bit is set
in the BDM. Even if the ENABLE bit in the BDM is cleared, the CPU
actually executes the BDM firmware code. It checks the ENABLE and
returns if ENABLE is not set. If the BDM is not serviced by the monitor then
the breakpoint would be re-asserted when the BDM returns to normal CPU
flow.
There is no hardware to enforce restriction of breakpoint operation if the
BDM is not enabled.
When program control returns from a tagged breakpoint through an RTI or
a BDM GO command, it will return to the instruction whose tag generated
the breakpoint. Unless breakpoints are disabled or modified in the service
routine or active BDM session, the instruction will be tagged again and the
breakpoint will be repeated. In the case of BDM breakpoints, this situation
can also be avoided by executing a TRACE1 command before the GO to
increment the program flow past the tagged instruction.
7.4.1.4 Using Comparator C in BKP Mode
The original BKP_ST12_A module supports two breakpoints. The DBG_ST12_A module can be used in
BKP mode and allow a third breakpoint using comparator C. Four additional bits, BKCEN, TAGC,
RWCEN, and RWC in DBGC2 in conjunction with additional comparator C address registers, DBGCCX,
DBGCCH, and DBGCCL allow the user to set up a third breakpoint. Using PAGSEL in DBGCCX for
expanded memory will work differently than the way paged memory is done using comparator A and B in
BKP mode. See Section 7.3.2.5, “Debug Comparator C Extended Register (DBGCCX),” for more
information on using comparator C.
7.4.2 DBG Operating in DBG Mode
Enabling the DBG module in DBG mode, allows the arming, triggering, and storing of data in the trace
buffer and can be used to cause CPU breakpoints. The DBG module is made up of three main blocks, the
comparators, trace buffer control logic, and the trace buffer.
NOTE
In general, there is a latency between the triggering event appearing on the
bus and being detected by the DBG circuitry. In general, tagged triggers will
be more predictable than forced triggers.
7.4.2.1 Comparators
The DBG contains three comparators, A, B, and C. Comparator A compares the core address bus with the
address stored in DBGCAH and DBGCAL. Comparator B compares the core address bus with the address
stored in DBGCBH and DBGCBL except in full mode, where it compares the data buses to the data stored
in DBGCBH and DBGCBL. Comparator C can be used as a breakpoint generator or as the address
comparison unit in the loop1 mode. Matches on comparator A, B, and C are signaled to the trace buffer
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 215
Rev 01.24
control (TBC) block. When PAGSEL = 01, registers DBGCAX, DBGCBX, and DBGCCX are used to
match the upper addresses as shown in Table 7-11.
NOTE
If a tagged-type C breakpoint is set at the same address as an A/B tagged-
type trigger (including the initial entry in an inside or outside range trigger),
the C breakpoint will have priority and the trigger will not be recognized.
7.4.2.1.1 Read or Write Comparison
Read or write comparisons are useful only with TRGSEL = 0, because only opcodes should be tagged as
they are “read” from memory. RWAEN and RWBEN are ignored when TRGSEL = 1.
In full modes (“A and B” and “A and not B”) RWAEN and RWA are used to select read or write
comparisons for both comparators A and B. Table 7-24 shows the effect for RWAEN, RWA, and RW on
the DBGCB comparison conditions. The RWBEN and RWB bits are not used and are ignored in full
modes.
7.4.2.1.2 Trigger Selection
The TRGSEL bit in DBGC1 is used to determine the triggering condition in DBG mode. TRGSEL applies
to both trigger A and B except in the event only trigger modes. By setting TRGSEL, the comparators A
and B will qualify a match with the output of opcode tracking logic and a trigger occurs before the tagged
instruction executes (tagged-type trigger). With the TRGSEL bit cleared, a comparator match forces a
trigger when the matching condition occurs (force-type trigger).
NOTE
If the TRGSEL is set, the address stored in the comparator match address
registers must be an opcode address for the trigger to occur.
7.4.2.2 Trace Buffer Control (TBC)
The TBC is the main controller for the DBG module. Its function is to decide whether data should be stored
in the trace buffer based on the trigger mode and the match signals from the comparator. The TBC also
determines whether a request to break the CPU should occur.
Table 7-24. Read or Write Comparison Logic Table
RWAEN bit RWA bit RW signal Comment
0 x 0 Write data bus
0 x 1 Read data bus
1 0 0 Write data bus
1 0 1 No data bus compare since RW=1
1 1 0 No data bus compare since RW=0
1 1 1 Read data bus
Chapter 7 Debug Module (DBGV1) Block Description
216 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.4.2.3 Begin- and End-Trigger
The definitions of begin- and end-trigger as used in the DBG module are as follows:
• Begin-trigger: Storage in trace buffer occurs after the trigger and continues until 64 locations are
filled.
• End-trigger: Storage in trace buffer occurs until the trigger, with the least recent data falling out of
the trace buffer if more than 64 words are collected.
7.4.2.4 Arming the DBG Module
In DBG mode, arming occurs by setting DBGEN and ARM in DBGC1. The ARM bit in DBGC1 is cleared
when the trigger condition is met in end-trigger mode or when the Trace Buffer is filled in begin-trigger
mode. The TBC logic determines whether a trigger condition has been met based on the trigger mode and
the trigger selection.
7.4.2.5 Trigger Modes
The DBG module supports nine trigger modes. The trigger modes are encoded as shown in Table 7-6. The
trigger mode is used as a qualifier for either starting or ending the storing of data in the trace buffer. When
the match condition is met, the appropriate flag A or B is set in DBGSC. Arming the DBG module clears
the A, B, and C flags in DBGSC. In all trigger modes except for the event-only modes and DETAIL capture
mode, change-of-flow addresses are stored in the trace buffer. In the event-only modes only the value on
the data bus at the trigger event B will be stored. In DETAIL capture mode address and data for all cycles
except program fetch (P) and free (f) cycles are stored in trace buffer.
7.4.2.5.1 A Only
In the A only trigger mode, if the match condition for A is met, the A flag in DBGSC is set and a trigger
occurs.
7.4.2.5.2 A or B
In the A or B trigger mode, if the match condition for A or B is met, the corresponding flag in DBGSC is
set and a trigger occurs.
7.4.2.5.3 A then B
In the A then B trigger mode, the match condition for A must be met before the match condition for B is
compared. When the match condition for A or B is met, the corresponding flag in DBGSC is set. The
trigger occurs only after A then B have matched.
NOTE
When tagging and using A then B, if addresses A and B are close together,
then B may not complete the trigger sequence. This occurs when A and B
are in the instruction queue at the same time. Basically the A trigger has not
yet occurred, so the B instruction is not tagged. Generally, if address B is at
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 217
Rev 01.24
least six addresses higher than address A (or B is lower than A) and there
are not changes of flow to put these in the queue at the same time, then this
operation should trigger properly.
7.4.2.5.4 Event-Only B (Store Data)
In the event-only B trigger mode, if the match condition for B is met, the B flag in DBGSC is set and a
trigger occurs. The event-only B trigger mode is considered a begin-trigger type and the BEGIN bit in
DBGC1 is ignored. Event-only B is incompatible with instruction tagging (TRGSEL = 1), and thus the
value of TRGSEL is ignored. Please refer to Section 7.4.2.7, “Storage Memory,” for more information.
This trigger mode is incompatible with the detail capture mode so the detail capture mode will have
priority. TRGSEL and BEGIN will not be ignored and this trigger mode will behave as if it were “B only”.
7.4.2.5.5 A then Event-Only B (Store Data)
In the A then event-only B trigger mode, the match condition for A must be met before the match condition
for B is compared, after the A match has occurred, a trigger occurs each time B matches. When the match
condition for A or B is met, the corresponding flag in DBGSC is set. The A then event-only B trigger mode
is considered a begin-trigger type and BEGIN in DBGC1 is ignored. TRGSEL in DBGC1 applies only to
the match condition for A. Please refer to Section 7.4.2.7, “Storage Memory,” for more information.
This trigger mode is incompatible with the detail capture mode so the detail capture mode will have
priority. TRGSEL and BEGIN will not be ignored and this trigger mode will be the same as A then B.
7.4.2.5.6 A and B (Full Mode)
In the A and B trigger mode, comparator A compares to the address bus and comparator B compares to
the data bus. In the A and B trigger mode, if the match condition for A and B happen on the same bus cycle,
both the A and B flags in the DBGSC register are set and a trigger occurs.
If TRGSEL = 1, only matches from comparator A are used to determine if the trigger condition is met and
comparator B matches are ignored. If TRGSEL = 0, full-word data matches on an odd address boundary
(misaligned access) do not work unless the access is to a RAM that manages misaligned accesses in a
single clock cycle (which is typical of RAM modules used in HCS12 MCUs).
7.4.2.5.7 A and Not B (Full Mode)
In the A and not B trigger mode, comparator A compares to the address bus and comparator B compares
to the data bus. In the A and not B trigger mode, if the match condition for A and not B happen on the same
bus cycle, both the A and B flags in DBGSC are set and a trigger occurs.
If TRGSEL = 1, only matches from comparator A are used to determine if the trigger condition is met and
comparator B matches are ignored. As described in Section 7.4.2.5.6, “A and B (Full Mode),” full-word
data compares on misaligned accesses will not match expected data (and thus will cause a trigger in this
mode) unless the access is to a RAM that manages misaligned accesses in a single clock cycle.
Chapter 7 Debug Module (DBGV1) Block Description
218 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.4.2.5.8 Inside Range (A ≤ address ≤ B)
In the inside range trigger mode, if the match condition for A and B happen on the same bus cycle, both
the A and B flags in DBGSC are set and a trigger occurs. If a match condition on only A or only B occurs
no flags are set. If TRGSEL = 1, the inside range is accurate only to word boundaries. If TRGSEL = 0, an
aligned word access which straddles the range boundary will cause a trigger only if the aligned address is
within the range.
7.4.2.5.9 Outside Range (address < A or address > B)
In the outside range trigger mode, if the match condition for A or B is met, the corresponding flag in
DBGSC is set and a trigger occurs. If TRGSEL = 1, the outside range is accurate only to word boundaries.
If TRGSEL = 0, an aligned word access which straddles the range boundary will cause a trigger only if the
aligned address is outside the range.
7.4.2.5.10 Control Bit Priorities
The definitions of some of the control bits are incompatible with each other. Table 7-25 and the notes
associated with it summarize how these incompatibilities are managed:
• Read/write comparisons are not compatible with TRGSEL = 1. Therefore, RWAEN and RWBEN
are ignored.
• Event-only trigger modes are always considered a begin-type trigger. See Section 7.4.2.8.1,
“Storing with Begin-Trigger,” and Section 7.4.2.8.2, “Storing with End-Trigger.”
• Detail capture mode has priority over the event-only trigger/capture modes. Therefore, event-only
modes have no meaning in detail mode and their functions default to similar trigger modes.
Table 7-25. Resolution of Mode Conflicts
Mode
Normal / Loop1 Detail
Tag Force Tag Force
A only
A or B
A then B
Event-only B 1 1, 3 3
A then event-only B 2 4 4
A and B (full mode) 5 5
A and not B (full mode) 5 5
Inside range 6 6
Outside range 6 6
1 — Ignored — same as force
2 — Ignored for comparator B
3 — Reduces to effectively “B only”
4 — Works same as A then B
5 — Reduces to effectively “A only” — B not compared
6 — Only accurate to word boundaries
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 219
Rev 01.24
7.4.2.6 Capture Modes
The DBG in DBG mode can operate in four capture modes. These modes are described in the following
subsections.
7.4.2.6.1 Normal Mode
In normal mode, the DBG module uses comparator A and B as triggering devices. Change-of-flow
information or data will be stored depending on TRG in DBGSC.
7.4.2.6.2 Loop1 Mode
The intent of loop1 mode is to prevent the trace buffer from being filled entirely with duplicate information
from a looping construct such as delays using the DBNE instruction or polling loops using
BRSET/BRCLR instructions. Immediately after address information is placed in the trace buffer, the DBG
module writes this value into the C comparator and the C comparator is placed in ignore address mode.
This will prevent duplicate address entries in the trace buffer resulting from repeated bit-conditional
branches. Comparator C will be cleared when the ARM bit is set in loop1 mode to prevent the previous
contents of the register from interfering with loop1 mode operation. Breakpoints based on comparator C
are disabled.
Loop1 mode only inhibits duplicate source address entries that would typically be stored in most tight
looping constructs. It will not inhibit repeated entries of destination addresses or vector addresses, because
repeated entries of these would most likely indicate a bug in the user’s code that the DBG module is
designed to help find.
NOTE
In certain very tight loops, the source address will have already been fetched
again before the C comparator is updated. This results in the source address
being stored twice before further duplicate entries are suppressed. This
condition occurs with branch-on-bit instructions when the branch is fetched
by the first P-cycle of the branch or with loop-construct instructions in
which the branch is fetched with the first or second P cycle. See examples
below:
LOOP INCX ; 1-byte instruction fetched by 1st P-cycle of BRCLR
BRCLR CMPTMP,#$0c,LOOP ; the BRCLR instruction also will be fetched by 1st P-cycle of BRCLR
LOOP2 BRN * ; 2-byte instruction fetched by 1st P-cycle of DBNE
NOP ; 1-byte instruction fetched by 2nd P-cycle of DBNE
DBNE A,LOOP2 ; this instruction also fetched by 2nd P-cycle of DBNE
NOTE
Loop1 mode does not support paged memory, and inhibits duplicate entries
in the trace buffer based solely on the CPU address. There is a remote
possibility of an erroneous address match if program flow alternates
between paged and unpaged memory space.
Chapter 7 Debug Module (DBGV1) Block Description
220 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.4.2.6.3 Detail Mode
In the detail mode, address and data for all cycles except program fetch (P) and free (f) cycles are stored
in trace buffer. This mode is intended to supply additional information on indexed, indirect addressing
modes where storing only the destination address would not provide all information required for a user to
determine where his code was in error.
7.4.2.6.4 Profile Mode
This mode is intended to allow a host computer to poll a running target and provide a histogram of program
execution. Each read of the trace buffer address will return the address of the last instruction executed. The
DBGCNT register is not incremented and the trace buffer does not get filled. The ARM bit is not used and
all breakpoints and all other debug functions will be disabled.
7.4.2.7 Storage Memory
The storage memory is a 64 words deep by 16-bits wide dual port RAM array. The CPU accesses the RAM
array through a single memory location window (DBGTBH:DBGTBL). The DBG module stores trace
information in the RAM array in a circular buffer format. As data is read via the CPU, a pointer into the
RAM will increment so that the next CPU read will receive fresh information. In all trigger modes except
for event-only and detail capture mode, the data stored in the trace buffer will be change-of-flow addresses.
change-of-flow addresses are defined as follows:
• Source address of conditional branches (long, short, BRSET, and loop constructs) taken
• Destination address of indexed JMP, JSR, and CALL instruction
• Destination address of RTI, RTS, and RTC instructions
• Vector address of interrupts except for SWI and BDM vectors
In the event-only trigger modes only the 16-bit data bus value corresponding to the event is stored. In the
detail capture mode, address and then data are stored for all cycles except program fetch (P) and free (f)
cycles.
7.4.2.8 Storing Data in Memory Storage Buffer
7.4.2.8.1 Storing with Begin-Trigger
Storing with begin-trigger can be used in all trigger modes. When DBG mode is enabled and armed in the
begin-trigger mode, data is not stored in the trace buffer until the trigger condition is met. As soon as the
trigger condition is met, the DBG module will remain armed until 64 words are stored in the trace buffer.
If the trigger is at the address of the change-of-flow instruction the change-of-flow associated with the
trigger event will be stored in the trace buffer.
7.4.2.8.2 Storing with End-Trigger
Storing with end-trigger cannot be used in event-only trigger modes. When DBG mode is enabled and
armed in the end-trigger mode, data is stored in the trace buffer until the trigger condition is met. When
the trigger condition is met, the DBG module will become de-armed and no more data will be stored. If
Chapter 7 Debug Module (DBGV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 221
Rev 01.24
the trigger is at the address of a change-of-flow address the trigger event will not be stored in the trace
buffer.
7.4.2.9 Reading Data from Trace Buffer
The data stored in the trace buffer can be read using either the background debug module (BDM) module
or the CPU provided the DBG module is enabled and not armed. The trace buffer data is read out first-in
first-out. By reading CNT in DBGCNT the number of valid words can be determined. CNT will not
decrement as data is read from DBGTBH:DBGTBL. The trace buffer data is read by reading
DBGTBH:DBGTBL with a 16-bit read. Each time DBGTBH:DBGTBL is read, a pointer in the DBG will
be incremented to allow reading of the next word.
Reading the trace buffer while the DBG module is armed will return invalid data and no shifting of the
RAM pointer will occur.
NOTE
The trace buffer should be read with the DBG module enabled and in the
same capture mode that the data was recorded. The contents of the trace
buffer counter register (DBGCNT) are resolved differently in detail mode
verses the other modes and may lead to incorrect interpretation of the trace
buffer data.
7.4.3 Breakpoints
There are two ways of getting a breakpoint in DBG mode. One is based on the trigger condition of the
trigger mode using comparator A and/or B, and the other is using comparator C. External breakpoints
generated using the TAGHI and TAGLO external pins are disabled in DBG mode.
7.4.3.1 Breakpoint Based on Comparator A and B
A breakpoint request to the CPU can be enabled by setting DBGBRK in DBGC1. The value of BEGIN in
DBGC1 determines when the breakpoint request to the CPU will occur. When BEGIN in DBGC1 is set,
begin-trigger is selected and the breakpoint request will not occur until the trace buffer is filled with
64 words. When BEGIN in DBGC1 is cleared, end-trigger is selected and the breakpoint request will occur
immediately at the trigger cycle.
There are two types of breakpoint requests supported by the DBG module, tagged and forced. Tagged
breakpoints are associated with opcode addresses and allow breaking just before a specific instruction
executes. Forced breakpoints are not associated with opcode addresses and allow breaking at the next
instruction boundary. The type of breakpoint based on comparators A and B is determined by TRGSEL in
the DBGC1 register (TRGSEL = 1 for tagged breakpoint, TRGSEL = 0 for forced breakpoint). Table 7-26
illustrates the type of breakpoint that will occur based on the debug run.
Chapter 7 Debug Module (DBGV1) Block Description
222 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
7.4.3.2 Breakpoint Based on Comparator C
A breakpoint request to the CPU can be created if BKCEN in DBGC2 is set. Breakpoints based on a
successful comparator C match can be accomplished regardless of the mode of operation for comparator
A or B, and do not affect the status of the ARM bit. TAGC in DBGC2 is used to select either tagged or
forced breakpoint requests for comparator C. Breakpoints based on comparator C are disabled in LOOP1
mode.
NOTE
Because breakpoints cannot be disabled when the DBG is armed, one must
be careful to avoid an “infinite breakpoint loop” when using tagged-type C
breakpoints while the DBG is armed. If BDM breakpoints are selected,
executing a TRACE1 instruction before the GO instruction is the
recommended way to avoid re-triggering a breakpoint if one does not wish
to de-arm the DBG. If SWI breakpoints are selected, disarming the DBG in
the SWI interrupt service routine is the recommended way to avoid re-
triggering a breakpoint.
7.5 Resets
The DBG module is disabled after reset.
The DBG module cannot cause a MCU reset.
7.6 Interrupts
The DBG contains one interrupt source. If a breakpoint is requested and BDM in DBGC2 is cleared, an
SWI interrupt will be generated.
Table 7-26. Breakpoint Setup
BEGIN TRGSEL DBGBRK Type of Debug Run
0 0 0 Fill trace buffer until trigger address
(no CPU breakpoint — keep running)
0 0 1 Fill trace buffer until trigger address, then a forced breakpoint
request occurs
0 1 0 Fill trace buffer until trigger opcode is about to execute
(no CPU breakpoint — keep running)
0 1 1 Fill trace buffer until trigger opcode about to execute, then a
tagged breakpoint request occurs
1 0 0 Start trace buffer at trigger address
(no CPU breakpoint — keep running)
1 0 1 Start trace buffer at trigger address, a forced breakpoint
request occurs when trace buffer is full
1 1 0 Start trace buffer at trigger opcode
(no CPU breakpoint — keep running)
1 1 1 Start trace buffer at trigger opcode, a forced breakpoint request
occurs when trace buffer is full
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 223
Rev 01.24
Chapter 8
Analog-to-Digital Converter (ATD10B8C)
Block Description
8.1 Introduction
The ATD10B8C is an 8-channel, 10-bit, multiplexed input successive approximation analog-to-digital
converter. Refer to device electrical specifications for ATD accuracy.
The block is designed to be upwards compatible with the 68HC11 standard 8-bit A/D converter. In
addition, there are new operating modes that are unique to the HC12 design.
8.1.1 Features
• 8/10-bit resolution.
•7µsec, 10-bit single conversion time.
• Sample buffer amplifier.
• Programmable sample time.
• Left/right justified, signed/unsigned result data.
• External trigger control.
• Conversion completion interrupt generation.
• Analog input multiplexer for eight analog input channels.
• Analog/digital input pin multiplexing.
• 1-to-8 conversion sequence lengths.
• Continuous conversion mode.
• Multiple channel scans.
8.1.2 Modes of Operation
8.1.2.1 Conversion Modes
There is software programmable selection between performing single or continuous conversion on a
single channel or multiple channels.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
224 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.1.2.2 MCU Operating Modes
• Stop Mode
Entering stop mode causes all clocks to halt and thus the system is placed in a minimum power
standby mode. This aborts any conversion sequence in progress. During recovery from stop mode,
there must be a minimum delay for the stop recovery time, tSR, before initiating a new ATD
conversion sequence.
• Wait Mode
Entering wait mode the ATD conversion either continues or aborts for low power depending on the
logical value of the AWAIT bit.
• Freeze Mode
In freeze mode the ATD10B8C will behave according to the logical values of the FRZ1 and FRZ0
bits. This is useful for debugging and emulation.
8.1.3 Block Diagram
Figure 8-1 is a block diagram of the ATD.
Figure 8-1. ATD10B8C Block Diagram
VRL
AN0 / PAD0
ATD10B8C
PORT AD DATA REGISTER
ANALOG
MUX
MODE AND TIMING CONTROL
SUCCESSIVE
APPROXIMATION
REGISTER (SAR)
RESULTS
ATD 0
ATD 1
ATD 2
ATD 3
ATD 4
ATD 5
ATD 6
ATD 7
AND DAC
AN7 / PAD7
AN6 / PAD6
AN5 / PAD5
AN4 / PAD4
AN3 / PAD3
AN2 / PAD2
AN1 / PAD1
SAMPLE & HOLD
1
1
VRH
VSSA
VDDA
CONVERSION
COMPLETE INTERRUPT
+
–
COMPARATOR
CLOCK
PRESCALER
BUS CLOCK ATD CLOCK
ATD INPUT ENABLE REGISTER
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 225
Rev 01.24
8.2 Signal Description
The ATD10B8C has a total of 12 external pins.
8.2.1 AN7 / ETRIG / PAD7
This pin serves as the analog input channel 7. It can be configured to provide an external trigger for the
ATD conversion. It can be configured as general-purpose digital I/O.
8.2.2 AN6 / PAD6
This pin serves as the analog input channel 6. It can be configured as general-purpose digital I/O.
8.2.3 AN5 / PAD5
This pin serves as the analog input channel 5. It can be configured as general-purpose digital I/O.
8.2.4 AN4 / PAD4
This pin serves as the analog input channel 4. It can be configured as general-purpose digital I/O.
8.2.5 AN3 / PAD3
This pin serves as the analog input channel 3. It can be configured as general-purpose digital I/O.
8.2.6 AN2 / PAD2
This pin serves as the analog input channel 2. It can be configured as general-purpose digital I/O.
8.2.7 AN1 / PAD1
This pin serves as the analog input channel 1. It can be configured as general-purpose digital I/O.
8.2.8 AN0 / PAD0
This pin serves as the analog input channel 0. It can be configured as general-purpose digital I/O.
8.2.9 VRH, VRL
VRH is the high reference voltage and VRL is the low reference voltage for ATD conversion.
8.2.10 VDDA, VSSA
These pins are the power supplies for the analog circuitry of the ATD10B8C block.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
226 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3 Memory Map and Registers
This section provides a detailed description of all registers accessible in the ATD10B8C.
8.3.1 Module Memory Map
Figure 8-2 gives an overview on all ATD10B8C registers.
Address Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000 ATDCTL0 R0 00000 0 0
W
0x0001 ATDCTL1 R0 00000 0 0
W
0x0002 ATDCTL2 RADPU AFFC AWAI ETRIGLE ETRIGP ETRIGE ASCIE ASCIF
W
0x0003 ATDCTL3 R0 S8C S4C S2C S1C FIFO FRZ1 FRZ0
W
0x0004 ATDCTL4 RSRES8 SMP1 SMP0 PRS4 PRS3 PRS2 PRS1 PRS0
W
0x0005 ATDCTL5 RDJM DSGN SCAN MULT 0CC CB CA
W
0x0006 ATDSTAT0 RSCF 0ETORF FIFOR 0 CC2 CC1 CC0
W
0x0007 Unimplemented R0 00000 0 0
W
0x0008 ATDTEST0 RU UUUUU U U
W
0x0009 ATDTEST1 RU UUUUU USC
W
0x000A Unimplemented R0 00000 0 0
W
0x000B ATDSTAT1 R CCF7 CCF6 CCF5 CCF4 CCF3 CCF2 CCF1 CCF0
W
0x000C Unimplemented R0 00000 0 0
W
0x000D ATDDIEN RIEN7 IEN6 IEN5 IEN4 IEN3 IEN2 IEN1 IEN0
W
0x000E Unimplemented R0 00000 0 0
W
0x000F PORTAD R PTAD7 PTAD6 PTAD5 PTAD4 PTAD3 PTAD2 PTAD1 PTAD0
W
= Unimplemented or Reserved
Figure 8-2. ATD Register Summary (Sheet 1 of 4)
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 227
Rev 01.24
Left Justified Result Data
0x0010 ATDDR0H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x0011 ATDDR0L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
0x0012 ATDDR1H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x0013 ATDDR1L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
0x0014 ATDDR2H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x0015 ATDDR2L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
0x0016 ATDDR3H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x0017 ATDDR3L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
0x0018 ATDDR4H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x0019 ATDDR4L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
0x001A ATDDR5H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x001B ATDDR5L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
0x001C ATDDR6H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x001D ATDDR6L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
Address Name Bit 7 6 5 4 3 2 1 Bit 0
= Unimplemented or Reserved
Figure 8-2. ATD Register Summary (Sheet 2 of 4)
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
228 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x001E ATDDR7H
R BIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
W
0x001F ATDDR7L
R BIT 1
u
BIT 0
u
0
0
0
0
0
0
0
0
0
0
0
0
W
Right Justified Result Data
0x0010 ATDDR0H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x0011 ATDDR0L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
0x0012 ATDDR1H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x0013 ATDDR1L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
0x0014 ATDDR2H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x0015 ATDDR2L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
0x0016 ATDDR3H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x0017 ATDDR3L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
0x0018 ATDDR4H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x0019 ATDDR4L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
0x001A ATDDR5H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x001B ATDDR5L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
Address Name Bit 7 6 5 4 3 2 1 Bit 0
= Unimplemented or Reserved
Figure 8-2. ATD Register Summary (Sheet 3 of 4)
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 229
Rev 01.24
NOTE
Register Address = Module Base Address + Address Offset, where the
Module Base Address is defined at the MCU level and the Address Offset is
defined at the module level.
0x001C ATDDR6H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x001D ATDDR6L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
0x001E ATDDR7H
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
W
0x001F ATDDR7L
R BIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
W
Address Name Bit 7 6 5 4 3 2 1 Bit 0
= Unimplemented or Reserved
Figure 8-2. ATD Register Summary (Sheet 4 of 4)
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
230 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2 Register Descriptions
This section describes in address order all the ATD10B8C registers and their individual bits.
8.3.2.1 Reserved Register (ATDCTL0)
Read: Always read $00 in normal modes
Write: Unimplemented in normal modes
8.3.2.2 Reserved Register (ATDCTL1)
Read: Always read $00 in normal modes
Write: Unimplemented in normal modes
NOTE
Writing to this registers when in special modes can alter functionality.
Module Base + 0x0000
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 8-3. Reserved Register (ATDCTL0)
Module Base + 0x0001
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 8-4. Reserved Register (ATDCTL1)
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 231
Rev 01.24
8.3.2.3 ATD Control Register 2 (ATDCTL2)
This register controls power down, interrupt, and external trigger. Writes to this register will abort current
conversion sequence but will not start a new sequence.
Read: Anytime
Write: Anytime
Module Base + 0x0002
76543210
R
ADPU AFFC AWAI ETRIGLE ETRIGP ETRIGE ASCIE
ASCIF
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 8-5. ATD Control Register 2 (ATDCTL2)
Table 8-1. ATDCTL2 Field Descriptions
Field Description
7
ADPU
ATD Power Down — This bit provides on/off control over the ATD10B8C block allowing reduced MCU power
consumption. Because analog electronic is turned off when powered down, the ATD requires a recovery time
period after ADPU bit is enabled.
0 Power down ATD
1 Normal ATD functionality
6
AFFC
ATD Fast Flag Clear All
0 ATD flag clearing operates normally (read the status register ATDSTAT1 before reading the result register to
clear the associate CCF flag).
1 Changes all ATD conversion complete flags to a fast clear sequence. Any access to a result register will cause
the associate CCF flag to clear automatically.
5
AWAI
ATD Power Down in Wait Mode — When entering Wait Mode this bit provides on/off control over the ATD10B8C
block allowing reduced MCU power. Because analog electronic is turned off when powered down, the ATD
requires a recovery time period after exit from Wait mode.
0 ATD continues to run in Wait mode
1 Halt conversion and power down ATD during Wait mode
After exiting Wait mode with an interrupt conversion will resume. But due to the recovery time the result of this
conversion should be ignored.
4
ETRIGLE
External Trigger Level/Edge Control — This bit controls the sensitivity of the external trigger signal. See
Table 8-2 for details.
3
ETRIGP
External Trigger Polarity — This bit controls the polarity of the external trigger signal. See Table 8-2 for details.
2
ETRIGE
External Trigger Mode Enable — This bit enables the external trigger on ATD channel 7. The external trigger
allows to synchronize sample and ATD conversions processes with external events.
0 Disable external trigger
1 Enable external trigger
Note: The conversion results for the external trigger ATD channel 7 have no meaning while external trigger mode
is enabled.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
232 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2.4 ATD Control Register 3 (ATDCTL3)
This register controls the conversion sequence length, FIFO for results registers and behavior in Freeze
Mode. Writes to this register will abort current conversion sequence but will not start a new sequence.
Read: Anytime
Write: Anytime
1
ASCIE
ATD Sequence Complete Interrupt Enable
0 ATD Sequence Complete interrupt requests are disabled.
1 ATD Interrupt will be requested whenever ASCIF = 1 is set.
0
ASCIF
ATD Sequence Complete Interrupt Flag — If ASCIE = 1 the ASCIF flag equals the SCF flag (see
Section 8.3.2.7, “ATD Status Register 0 (ATDSTAT0)”), else ASCIF reads zero. Writes have no effect.
0 No ATD interrupt occurred
1 ATD sequence complete interrupt pending
Table 8-2. External Trigger Configurations
ETRIGLE ETRIGP External Trigger Sensitivity
0 0 Falling edge
0 1 Rising edge
1 0 Low level
1 1 High level
Module Base + 0x0003
76543210
R0
S8C S4C S2C S1C FIFO FRZ1 FRZ0
W
Reset 0 0 1 00000
= Unimplemented or Reserved
Figure 8-6. ATD Control Register 3 (ATDCTL3)
Table 8-3. ATDCTL3 Field Descriptions
Field Description
6–3
S8C, S4C,
S2C, S1C
Conversion Sequence Length — These bits control the number of conversions per sequence. Table 8-4 shows
all combinations. At reset, S4C is set to 1 (sequence length is 4). This is to maintain software continuity to HC12
Family.
Table 8-1. ATDCTL2 Field Descriptions (continued)
Field Description
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 233
Rev 01.24
2
FIFO
Result Register FIFO Mode — If this bit is zero (non-FIFO mode), the A/D conversion results map into the result
registers based on the conversion sequence; the result of the first conversion appears in the first result register,
the second result in the second result register, and so on.
If this bit is one (FIFO mode) the conversion counter is not reset at the beginning or ending of a conversion
sequence; sequential conversion results are placed in consecutive result registers. In a continuously scanning
conversion sequence, the result register counter will wrap around when it reaches the end of the result register
file. The conversion counter value (CC2-0 in ATDSTAT0) can be used to determine where in the result register
file, the current conversion result will be placed.
Aborting a conversion or starting a new conversion by write to an ATDCTL register (ATDCTL5-0) clears the
conversion counter even if FIFO=1. So the first result of a new conversion sequence, started by writing to
ATDCTL5, will always be place in the first result register (ATDDDR0). Intended usage of FIFO mode is continuos
conversion (SCAN=1) or triggered conversion (ETRIG=1).
Which result registers hold valid data can be tracked using the conversion complete flags. Fast flag clear mode
may or may not be useful in a particular application to track valid data.
0 Conversion results are placed in the corresponding result register up to the selected sequence length.
1 Conversion results are placed in consecutive result registers (wrap around at end).
1–0
FRIZ[1:0]
Background Debug Freeze Enable — When debugging an application, it is useful in many cases to have the
ATD pause when a breakpoint (Freeze Mode) is encountered. These 2 bits determine how the ATD will respond
to a breakpoint as shown in Table 8-5. Leakage onto the storage node and comparator reference capacitors may
compromise the accuracy of an immediately frozen conversion depending on the length of the freeze period.
Table 8-4. Conversion Sequence Length Coding
S8C S4C S2C S1C Number of Conversions per
Sequence
00 0 0 8
00 0 1 1
00 1 0 2
00 1 1 3
01 0 0 4
01 0 1 5
01 1 0 6
01 1 1 7
1X X X 8
Table 8-5. ATD Behavior in Freeze Mode (Breakpoint)
FRZ1 FRZ0 Behavior in Freeze Mode
0 0 Continue conversion
0 1 Reserved
1 0 Finish current conversion, then freeze
1 1 Freeze Immediately
Table 8-3. ATDCTL3 Field Descriptions (continued)
Field Description
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
234 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2.5 ATD Control Register 4 (ATDCTL4)
This register selects the conversion clock frequency, the length of the second phase of the sample time and
the resolution of the A/D conversion (i.e.: 8-bits or 10-bits). Writes to this register will abort current
conversion sequence but will not start a new sequence.
Read: Anytime
Write: Anytime
Module Base + 0x0004
76543210
R
SRES8 SMP1 SMP0 PRS4 PRS3 PRS2 PRS1 PRS0
W
Reset 0 0 0 00101
Figure 8-7. ATD Control Register 4 (ATDCTL4)
Table 8-6. ATDCTL4 Field Descriptions
Field Description
7
SRES8
A/D Resolution Select — This bit selects the resolution of A/D conversion results as either 8 or 10 bits. The A/D
converter has an accuracy of 10 bits; however, if low resolution is required, the conversion can be speeded up
by selecting 8-bit resolution.
0 10-bit resolution
1 8-bit resolution
6–5
SMP[1:0]
Sample Time Select — These two bits select the length of the second phase of the sample time in units of ATD
conversion clock cycles. Note that the ATD conversion clock period is itself a function of the prescaler value (bits
PRS4-0). The sample time consists of two phases. The first phase is two ATD conversion clock cycles long and
transfers the sample quickly (via the buffer amplifier) onto the A/D machine’s storage node. The second phase
attaches the external analog signal directly to the storage node for final charging and high accuracy. Table 8-7
lists the lengths available for the second sample phase.
4–0
PRS[4:0}
ATD Clock Prescaler — These 5 bits are the binary value prescaler value PRS. The ATD conversion clock
frequency is calculated as follows:
Note: The maximum ATD conversion clock frequency is half the Bus Clock. The default (after reset) prescaler
value is 5 which results in a default ATD conversion clock frequency that is Bus Clock divided by 12.
Table 8-8 illustrates the divide-by operation and the appropriate range of the Bus Clock.
Table 8-7. Sample Time Select
SMP1 SMP0 Length of 2nd Phase of Sample Time
0 0 2 A/D conversion clock periods
0 1 4 A/D conversion clock periods
1 0 8 A/D conversion clock periods
1 1 16 A/D conversion clock periods
ATDclock BusClock[]
PRS 1+[]
------------------------------0.5×=
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 235
Rev 01.24
Table 8-8. Clock Prescaler Values
Prescale Value Total Divisor
Value
Maximum
Bus Clock(1)
1. Maximum ATD conversion clock frequency is 2 MHz. The maximum allowed bus clock frequency is
shown in this column.
Minimum
Bus Clock(2)
2. Minimum ATD conversion clock frequency is 500 kHz. The minimum allowed bus clock frequency
is shown in this column.
00000
00001
00010
00011
00100
00101
00110
00111
01000
01001
01010
01011
01100
01101
01110
01111
10000
10001
10010
10011
10100
10101
10110
10111
11000
11001
11010
11011
11100
11101
11110
11111
Divide by 2
Divide by 4
Divide by 6
Divide by 8
Divide by 10
Divide by 12
Divide by 14
Divide by 16
Divide by 18
Divide by 20
Divide by 22
Divide by 24
Divide by 26
Divide by 28
Divide by 30
Divide by 32
Divide by 34
Divide by 36
Divide by 38
Divide by 40
Divide by 42
Divide by 44
Divide by 46
Divide by 48
Divide by 50
Divide by 52
Divide by 54
Divide by 56
Divide by 58
Divide by 60
Divide by 62
Divide by 64
4 MHz
8 MHz
12 MHz
16 MHz
20 MHz
24 MHz
28 MHz
32 MHz
36 MHz
40 MHz
44 MHz
48 MHz
52 MHz
56 MHz
60 MHz
64 MHz
68 MHz
72 MHz
76 MHz
80 MHz
84 MHz
88 MHz
92 MHz
96 MHz
100 MHz
104 MHz
108 MHz
112 MHz
116 MHz
120 MHz
124 MHz
128 MHz
1 MHz
2 MHz
3 MHz
4 MHz
5 MHz
6 MHz
7 MHz
8 MHz
9 MHz
10 MHz
11 MHz
12 MHz
13 MHz
14 MHz
15 MHz
16 MHz
17 MHz
18 MHz
19 MHz
20 MHz
21 MHz
22 MHz
23 MHz
24 MHz
25 MHz
26 MHz
27 MHz
28 MHz
29 MHz
30 MHz
31 MHz
32 MHz
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
236 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2.6 ATD Control Register 5 (ATDCTL5)
This register selects the type of conversion sequence and the analog input channels sampled. Writes to this
register will abort current conversion sequence and start a new conversion sequence.
Read: Anytime
Write: Anytime
Module Base + 0x0005
76543210
R
DJM DSGN SCAN MULT
0
CC CB CA
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 8-8. ATD Control Register 5 (ATDCTL5)
Table 8-9. ATDCTL5 Field Descriptions
Field Description
7
DJM
Result Register Data Justification — This bit controls justification of conversion data in the result registers.
See Section 8.3.2.13, “ATD Conversion Result Registers (ATDDRHx/ATDDRLx)” for details.
0 Left justified data in the result registers
1 Right justified data in the result registers
6
DSGN
Result Register Data Signed or Unsigned Representation — This bit selects between signed and unsigned
conversion data representation in the result registers. Signed data is represented as 2’s complement. Signed
data is not available in right justification. See Section 8.3.2.13, “ATD Conversion Result Registers
(ATDDRHx/ATDDRLx)” for details.
0 Unsigned data representation in the result registers
1 Signed data representation in the result registers
Table 8-10 summarizes the result data formats available and how they are set up using the control bits.
Table 8-11 illustrates the difference between the signed and unsigned, left justified output codes for an input
signal range between 0 and 5.12 Volts.
5
SCAN
Continuous Conversion Sequence Mode — This bit selects whether conversion sequences are performed
continuously or only once.
0 Single conversion sequence
1 Continuous conversion sequences (scan mode)
4
MULT
Multi-Channel Sample Mode — When MULT is 0, the ATD sequence controller samples only from the specified
analog input channel for an entire conversion sequence. The analog channel is selected by channel selection
code (control bits CC/CB/CA located in ATDCTL5). When MULT is 1, the ATD sequence controller samples
across channels. The number of channels sampled is determined by the sequence length value (S8C, S4C, S2C,
S1C). The first analog channel examined is determined by channel selection code (CC, CB, CA control bits);
subsequent channels sampled in the sequence are determined by incrementing the channel selection code.
0 Sample only one channel
1 Sample across several channels
2–1
CC, CB, CA
Analog Input Channel Select Code — These bits select the analog input channel(s) whose signals are
sampled and converted to digital codes. Table 8-12 lists the coding used to select the various analog input
channels. In the case of single channel scans (MULT = 0), this selection code specified the channel examined.
In the case of multi-channel scans (MULT = 1), this selection code represents the first channel to be examined
in the conversion sequence. Subsequent channels are determined by incrementing channel selection code;
selection codes that reach the maximum value wrap around to the minimum value.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 237
Rev 01.24
Table 8-10. Available Result Data Formats
SRES8 DJM DSGN Result Data Formats
Description and Bus Bit Mapping
1
1
1
0
0
0
0
0
1
0
0
1
0
1
X
0
1
X
8-bit / left justified / unsigned — bits 8–15
8-bit / left justified / signed — bits 8–15
8-bit / right justified / unsigned — bits 0–7
10-bit / left justified / unsigned — bits 6–15
10-bit / left justified / signed — bits 6–15
10-bit / right justified / unsigned — bits 0–9
Table 8-11. Left Justified, Signed, and Unsigned ATD Output Codes.
Input Signal
VRL = 0 Volts
VRH = 5.12 Volts
Signed
8-Bit
Codes
Unsigned
8-Bit
Codes
Signed
10-Bit
Codes
Unsigned
10-Bit
Codes
5.120 Volts
5.100
5.080
2.580
2.560
2.540
0.020
0.000
7F
7F
7E
01
00
FF
81
80
FF
FF
FE
81
80
7F
01
00
7FC0
7F00
7E00
0100
0000
FF00
8100
8000
FFC0
FF00
FE00
8100
8000
7F00
0100
0000
Table 8-12. Analog Input Channel Select Coding
CC CB CA Analog Input Channel
000 AN0
001 AN1
010 AN2
011 AN3
100 AN4
101 AN5
110 AN6
111 AN7
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
238 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2.7 ATD Status Register 0 (ATDSTAT0)
This read-only register contains the sequence complete flag, overrun flags for external trigger and FIFO
mode, and the conversion counter.
Read: Anytime
Write: Anytime (no effect on (CC2, CC1, CC0))
Module Base + 0x0006
76543210
R
SCF
0
ETORF FIFOR
0 CC2 CC1 CC0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 8-9. ATD Status Register 0 (ATDSTAT0)
Table 8-13. ATDSTAT0 Field Descriptions
Field Description
7
SCF
Sequence Complete Flag — This flag is set upon completion of a conversion sequence. If conversion
sequences are continuously performed (SCAN = 1), the flag is set after each one is completed. This flag is
cleared when one of the following occurs:
A) Write “1” to SCF
B) Write to ATDCTL5 (a new conversion sequence is started)
C) If AFFC=1 and read of a result register
0 Conversion sequence not completed
1 Conversion sequence has completed
5
ETORF
External Trigger Overrun Flag — While in edge trigger mode (ETRIGLE = 0), if additional active edges are
detected while a conversion sequence is in process the overrun flag is set. This flag is cleared when one of the
following occurs:
A) Write “1” to ETORF
B) Write to ATDCTL2, ATDCTL3 or ATDCTL4 (a conversion sequence is aborted)
C) Write to ATDCTL5 (a new conversion sequence is started)
0 No External trigger over run error has occurred
1 External trigger over run error has occurred
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 239
Rev 01.24
8.3.2.8 Reserved Register (ATDTEST0)
Read: Anytime, returns unpredictable values
Write: Anytime in special modes, unimplemented in normal modes
NOTE
Writing to this registers when in special modes can alter functionality.
4
FIFOR
FIFO Over Run Flag — This bit indicates that a result register has been written to before its associated
conversion complete flag (CCF) has been cleared. This flag is most useful when using the FIFO mode because
the flag potentially indicates that result registers are out of sync with the input channels. However, it is also
practical for non-FIFO modes, and indicates that a result register has been over written before it has been read
(i.e. the old data has been lost). This flag is cleared when one of the following occurs:
A) Write “1” to FIFOR
B) Start a new conversion sequence (write to ATDCTL5 or external trigger)
0 No over run has occurred
1 An over run condition exists
2–0
CC[2:0]
Conversion Counter — These 3 read-only bits are the binary value of the conversion counter. The conversion
counter points to the result register that will receive the result of the current conversion. For example, CC2 = 1,
CC1 = 1, CC0 = 0 indicates that the result of the current conversion will be in ATD Result Register 6. If in non-
FIFO mode (FIFO = 0) the conversion counter is initialized to zero at the begin and end of the conversion
sequence. If in FIFO mode (FIFO = 1) the register counter is not initialized. The conversion counters wraps
around when its maximum value is reached.
Aborting a conversion or starting a new conversion by write to an ATDCTL register (ATDCTL5-2) clears the
conversion counter even if FIFO=1.
Module Base + 0x0008
76543210
RUUUUUUUU
W
Reset 1 0 0 00000
= Unimplemented or Reserved
Figure 8-10. Reserved Register (ATDTEST0)
Table 8-13. ATDSTAT0 Field Descriptions (continued)
Field Description
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
240 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2.9 ATD Test Register 1 (ATDTEST1)
This register contains the SC bit used to enable special channel conversions.
Read: Anytime, returns unpredictable values for Bit 7 and Bit 6
Write: Anytime
Module Base + 0x0009
76543210
RUUUUUUU
SC
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 8-11. ATD Test Register 1 (ATDTEST1)
Table 8-14. ATDTEST1 Field Descriptions
Field Description
0
SC
Special Channel Conversion Bit — If this bit is set, then special channel conversion can be selected using CC,
CB, and CA of ATDCTL5. Table 8-15 lists the coding.
0 Special channel conversions disabled
1 Special channel conversions enabled
Note: Always write remaining bits of ATDTEST1 (Bit7 to Bit1) zero when writing SC bit. Not doing so might result
in unpredictable ATD behavior.
Table 8-15. Special Channel Select Coding
SC CC CB CA Analog Input Channel
1 0 X X Reserved
1100 V
RH
1101 V
RL
1110 (V
RH+VRL) / 2
1 1 1 1 Reserved
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 241
Rev 01.24
8.3.2.10 ATD Status Register 1 (ATDSTAT1)
This read-only register contains the Conversion Complete Flags.
Read: Anytime
Write: Anytime, no effect
Module Base + 0x000B
76543210
R CCF7 CCF6 CCF5 CCF4 CCF3 CCF2 CCF1 CCF0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 8-12. ATD Status Register 1 (ATDSTAT1)
Table 8-16. ATDSTAT1 Field Descriptions
Field Description
7–0
CCF[7:0]
Conversion Complete Flag x (x = 7, 6, 5, 4, 3, 2, 1, 0) — A conversion complete flag is set at the end of each
conversion in a conversion sequence. The flags are associated with the conversion position in a sequence (and
also the result register number). Therefore, CCF0 is set when the first conversion in a sequence is complete and
the result is available in result register ATDDR0; CCF1 is set when the second conversion in a sequence is
complete and the result is available in ATDDR1, and so forth. A flag CCFx (x = 7, 6, 5, 4, 3, 2, 1, 0) is cleared
when one of the following occurs:
A) Write to ATDCTL5 (a new conversion sequence is started)
B) If AFFC = 0 and read of ATDSTAT1 followed by read of result register ATDDRx
C) If AFFC = 1 and read of result register ATDDRx
0 Conversion number x not completed
1 Conversion number x has completed, result ready in ATDDRx
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
242 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2.11 ATD Input Enable Register (ATDDIEN)
Read: Anytime
Write: Anytime
Module Base + 0x000D
76543210
R
IEN7 IEN6 IEN5 IEN4 IEN3 IEN2 IEN1 IEN0
W
Reset 0 0 0 00000
Figure 8-13. ATD Input Enable Register (ATDDIEN)
Table 8-17. ATDDIEN Field Descriptions
Field Description
7–0
IEN[7:0]
ATD Digital Input Enable on channel x (x = 7, 6, 5, 4, 3, 2, 1, 0) — This bit controls the digital input buffer from
the analog input pin (ANx) to PTADx data register.
0 Disable digital input buffer to PTADx
1 Enable digital input buffer to PTADx.
Note: Setting this bit will enable the corresponding digital input buffer continuously. If this bit is set while
simultaneously using it as an analog port, there is potentially increased power consumption because the
digital input buffer maybe in the linear region.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 243
Rev 01.24
8.3.2.12 Port Data Register (PORTAD)
The data port associated with the ATD is general purpose I/O. The port pins are shared with the analog
A/D inputs AN7–AN0.
Read: Anytime
Write: Anytime, no effect
The A/D input channels may be used for general-purpose digital I/0.
8.3.2.13 ATD Conversion Result Registers (ATDDRHx/ATDDRLx)
The A/D conversion results are stored in 8 read-only result registers ATDDRHx/ATDDRLx. The result
data is formatted in the result registers based on two criteria. First there is left and right justification; this
selection is made using the DJM control bit in ATDCTL5. Second there is signed and unsigned data; this
selection is made using the DSGN control bit in ATDCTL5. Signed data is stored in 2’s complement
format and only exists in left justified format. Signed data selected for right justified format is ignored.
Read: Anytime
Write: Anytime, no effect in normal modes
Module Base + 0x000F
76543210
R PTAD7 PTAD6 PTAD5 PTAD4 PTAD3 PTAD2 PTAD1 PTAD0
W
Reset 1 1 1 11111
Pin
Function AN7 AN6 AN5 AN4 AN3‘ AN2 AN1 AN0
= Unimplemented or Reserved
Figure 8-14. Port Data Register (PORTAD)
Table 8-18. PORTAD Field Descriptions
Field Description
7
PTAD[7:0]
A/D Channel x (ANx) Digital Input (x = 7, 6, 5, 4, 3, 2, 1, 0) — If the digital input buffer on the ANx pin is enabled
(IENx = 1) read returns the logic level on ANx pin (signal potentials not meeting VIL or VIH specifications will have
an indeterminate value)).
If the digital input buffers are disabled (IENx = 0), read returns a “1”.
Reset sets all PORTAD bits to “1”.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
244 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.3.2.13.1 Left Justified Result Data
8.3.2.13.2 Right Justified Result Data
Module Base + 0x0010 = ATDDR0H, 0x0012 = ATDDR1H, 0x0014 = ATDDR2H, 0x0016 = ATDDR3H
0x0018 = ATDDR4H, 0x001A = ATDDR5H, 0x001C = ATDDR6H, 0x001E = ATDDR7H
76543210
RBIT 9 MSB
BIT 7 MSB
BIT 8
BIT 6
BIT 7
BIT 5
BIT 6
BIT 4
BIT 5
BIT 3
BIT 4
BIT 2
BIT 3
BIT 1
BIT 2
BIT 0
10-bit data
8-bit data
W
Reset 0 0 0 0 0 0 0 0
Figure 8-15. Left Justified, ATD Conversion Result Register, High Byte (ATDDRxH)
Module Base + 0x0011 = ATDDR0L, 0x0013 = ATDDR1L, 0x0015 = ATDDR2L, 0x0017 = ATDDR3L
0x0019 = ATDDR4L, 0x001B = ATDDR5L, 0x001D = ATDDR6L, 0x001F = ATDDR7L
76543210
RBIT 1
U
BIT 0
U
0
0
0
0
0
0
0
0
0
0
0
0
10-bit data
8-bit data
W
Reset 0 0 0 0 0 0 0 0
Figure 8-16. Left Justified, ATD Conversion Result Register, Low Byte (ATDDRxL)
Module Base + 0x0010 = ATDDR0H, 0x0012 = ATDDR1H, 0x0014 = ATDDR2H, 0x0016 = ATDDR3H
0x0018 = ATDDR4H, 0x001A = ATDDR5H, 0x001C = ATDDR6H, 0x001E = ATDDR7H
76543210
R0
0
0
0
0
0
0
0
0
0
0
0
BIT 9 MSB
0
BIT 8
0
10-bit data
8-bit data
W
Reset 0 0 0 0 0 0 0 0
Figure 8-17. Right Justified, ATD Conversion Result Register, High Byte (ATDDRxH)
Module Base + 0x0011 = ATDDR0L, 0x0013 = ATDDR1L, 0x0015 = ATDDR2L, 0x0017 = ATDDR3L
0x0019 = ATDDR4L, 0x001B = ATDDR5L, 0x001D = ATDDR6L, 0x001F = ATDDR7L
76543210
RBIT 7
BIT 7 MSB
BIT 6
BIT 6
BIT 5
BIT 5
BIT 4
BIT 4
BIT 3
BIT 3
BIT 2
BIT 2
BIT 1
BIT 1
BIT 0
BIT 0
10-bit data
8-bit data
W
Reset 0 0 0 0 0 0 0 0
Figure 8-18. Right Justified, ATD Conversion Result Register, Low Byte (ATDDRxL)
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 245
Rev 01.24
8.4 Functional Description
The ATD10B8C is structured in an analog and a digital sub-block.
8.4.1 Analog Sub-block
The analog sub-block contains all analog electronics required to perform a single conversion. Separate
power supplies VDDA and VSSA allow to isolate noise of other MCU circuitry from the analog sub-block.
8.4.1.1 Sample and Hold Machine
The sample and hold (S/H) machine accepts analog signals from the external surroundings and stores them
as capacitor charge on a storage node.
The sample process uses a two stage approach. During the first stage, the sample amplifier is used to
quickly charge the storage node.The second stage connects the input directly to the storage node to
complete the sample for high accuracy.
When not sampling, the sample and hold machine disables its own clocks. The analog electronics still draw
their quiescent current. The power down (ADPU) bit must be set to disable both the digital clocks and the
analog power consumption.
The input analog signals are unipolar and must fall within the potential range of VSSA to VDDA.
8.4.1.2 Analog Input Multiplexer
The analog input multiplexer connects one of the 8 external analog input channels to the sample and hold
machine.
8.4.1.3 Sample Buffer Amplifier
The sample amplifier is used to buffer the input analog signal so that the storage node can be quickly
charged to the sample potential.
8.4.1.4 Analog-to-Digital (A/D) Machine
The A/D machine performs analog-to-digital conversions. The resolution is program selectable at either 8
or 10 bits. The A/D machine uses a successive approximation architecture. It functions by comparing the
stored analog sample potential with a series of digitally generated analog potentials. By following a binary
search algorithm, the A/D machine locates the approximating potential that is nearest to the sampled
potential.
When not converting the A/D machine disables its own clocks. The analog electronics still draws quiescent
current. The power down (ADPU) bit must be set to disable both the digital clocks and the analog power
consumption.
Only analog input signals within the potential range of VRL to VRH (A/D reference potentials) will result
in a non-railed digital output codes.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
246 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.4.2 Digital Sub-block
This subsection explains some of the digital features in more detail. See 7 for all details.
8.4.2.1 External Trigger Input (ETRIG)
The external trigger feature allows the user to synchronize ATD conversions to the external environment
events rather than relying on software to signal the ATD module when ATD conversions are to take place.
The input signal (ATD channel 7) is programmable to be edge or level sensitive with polarity control.
Table 8-19 gives a brief description of the different combinations of control bits and their affect on the
external trigger function
.
During a conversion, if additional active edges are detected the overrun error flag ETORF is set.
In either level or edge triggered modes, the first conversion begins when the trigger is received. In both
cases, the maximum latency time is one Bus Clock cycle plus any skew or delay introduced by the trigger
circuitry.
NOTE
The conversion results for the external trigger ATD channel 7 have no
meaning while external trigger mode is enabled.
Once ETRIGE is enabled, conversions cannot be started by a write to ATDCTL5, but rather must be
triggered externally.
If the level mode is active and the external trigger both de-asserts and re-asserts itself during a conversion
sequence, this does not constitute an overrun; therefore, the flag is not set. If the trigger is left asserted in
level mode while a sequence is completing, another sequence will be triggered immediately.
Table 8-19. External Trigger Control Bits
ETRIGLE ETRIGP ETRIGE SCAN Description
X X 0 0 Ignores external trigger. Performs one conversion sequence
and stops.
X X 0 1 Ignores external trigger. Performs continuous conversion
sequences.
0 0 1 X Falling edge triggered. Performs one conversion sequence
per trigger.
0 1 1 X Rising edge triggered. Performs one conversion sequence
per trigger.
1 0 1 X Trigger active low. Performs continuous conversions while
trigger is active.
1 1 1 X Trigger active high. Performs continuous conversions while
trigger is active.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 247
Rev 01.24
8.4.2.2 General-Purpose Digital Port Operation
The channel pins can be multiplexed between analog and digital data. As analog inputs, they are
multiplexed and sampled to supply signals to the A/D converter. Alternatively they can be configured as
digital I/O signals with the port I/O data being held in PORTAD.
The analog/digital multiplex operation is performed in the pads. The pad is always connected to the analog
inputs of the ATD10B8C. The pad signal is buffered to the digital port registers. This buffer can be turned
on or off with the ATDDIEN register. This is important so that the buffer does not draw excess current
when analog potentials are presented at its input.
8.4.2.3 Low-Power Modes
The ATD10B8C can be configured for lower MCU power consumption in three different ways:
1. Stop Mode: This halts A/D conversion. Exit from Stop mode will resume A/D conversion, But due
to the recovery time the result of this conversion should be ignored.
2. Wait Mode with AWAI = 1: This halts A/D conversion. Exit from Wait mode will resume A/D
conversion, but due to the recovery time the result of this conversion should be ignored.
3. Writing ADPU = 0 (Note that all ATD registers remain accessible.): This aborts any A/D
conversion in progress.
NOTE
The reset value for the ADPU bit is zero. Therefore, when this module is
reset, it is reset into the power down state.
8.5 Initialization/Application Information
8.5.1 Setting up and starting an A/D conversion
The following describes a typical setup procedure for starting A/D conversions. It is highly recommended
to follow this procedure to avoid common mistakes.
Each step of the procedure will have a general remark and a typical example
8.5.1.1 Step 1
Power up the ATD and concurrently define other settings in ATDCTL2
Example: Write to ATDCTL2: ADPU=1 -> powers up the ATD, ASCIE=1 enable interrupt on finish of a
conversion sequence.
8.5.1.2 Step 2
Wait for the ATD Recovery Time tREC before you proceed with Step 3.
Example: Use the CPU in a branch loop to wait for a defined number of bus clocks.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
248 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
8.5.1.3 Step 3
Configure how many conversions you want to perform in one sequence and define other settings in
ATDCTL3.
Example: Write S4C=1 to do 4 conversions per sequence.
8.5.1.4 Step 4
Configure resolution, sampling time and ATD clock speed in ATDCTL4.
Example: Use default for resolution and sampling time by leaving SRES8, SMP1 and SMP0 clear. For a
bus clock of 40MHz write 9 to PR4-0, this gives an ATD clock of 0.5*40MHz/(9+1) = 2MHz which is
within the allowed range for fATDCLK.
8.5.1.5 Step 5
Configure starting channel, single/multiple channel, continuous or single sequence and result data format
in ATDCTL5. Writing ATDCTL5 will start the conversion, so make sure your write ATDCTL5 in the last
step.
Example: Leave CC,CB,CA clear to start on channel AN0. Write MULT=1 to convert channel AN0 to
AN3 in a sequence (4 conversion per sequence selected in ATDCTL3).
8.5.2 Aborting an A/D conversion
8.5.2.1 Step 1
Disable the ATD Interrupt by writing ASCIE=0 in ATDCTL2. This will also abort any ongoing conversion
sequence.
It is important to clear the interrupt enable at this point, prior to step 3, as depending on the device clock
gating it may not always be possible to clear it or the SCF flag once the module is disabled (ADPU=0).
8.5.2.2 Step 2
Clear the SCF flag by writing a 1 in ATDSTAT0.
(Remaining flags will be cleared with the next start of a conversions, but SCF flag should be cleared to
avoid SCF interrupt.)
8.5.2.3 Step 3
Power down ATD by writing ADPU=0 in ATDCTL2.
8.6 Resets
At reset the ATD10B8C is in a power down state. The reset state of each individual bit is listed within
Section 8.3.2, “Register Descriptions” which details the registers and their bit-field.
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 249
Rev 01.24
8.7 Interrupts
The interrupt requested by the ATD10B8C is listed in Table 8-20. Refer to MCU specification for related
vector address and priority.
See Section 8.3.2, “Register Descriptions” for further details.
Table 8-20. ATD10B8C Interrupt Vectors
Interrupt Source CCR
Mask Local Enable
Sequence complete interrupt I bit ASCIE in ATDCTL2
Chapter 8 Analog-to-Digital Converter (ATD10B8C) Block Description
250 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 251
Rev 01.24
Chapter 9
Clocks and Reset Generator (CRGV4) Block Description
9.1 Introduction
This specification describes the function of the clocks and reset generator (CRGV4).
9.1.1 Features
The main features of this block are:
• Phase-locked loop (PLL) frequency multiplier
— Reference divider
— Automatic bandwidth control mode for low-jitter operation
— Automatic frequency lock detector
— CPU interrupt on entry or exit from locked condition
— Self-clock mode in absence of reference clock
• System clock generator
— Clock quality check
— Clock switch for either oscillator- or PLL-based system clocks
— User selectable disabling of clocks during wait mode for reduced power consumption
• Computer operating properly (COP) watchdog timer with time-out clear window
• System reset generation from the following possible sources:
— Power-on reset
— Low voltage reset
Refer to the device overview section for availability of this feature.
— COP reset
— Loss of clock reset
— External pin reset
• Real-time interrupt (RTI)
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
252 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.1.2 Modes of Operation
This subsection lists and briefly describes all operating modes supported by the CRG.
• Run mode
All functional parts of the CRG are running during normal run mode. If RTI or COP functionality
is required the individual bits of the associated rate select registers (COPCTL, RTICTL) have to be
set to a nonzero value.
• Wait mode
This mode allows to disable the system and core clocks depending on the configuration of the
individual bits in the CLKSEL register.
• Stop mode
Depending on the setting of the PSTP bit, stop mode can be differentiated between full stop mode
(PSTP = 0) and pseudo-stop mode (PSTP = 1).
— Full stop mode
The oscillator is disabled and thus all system and core clocks are stopped. The COP and the
RTI remain frozen.
— Pseudo-stop mode
The oscillator continues to run and most of the system and core clocks are stopped. If the
respective enable bits are set the COP and RTI will continue to run, else they remain frozen.
• Self-clock mode
Self-clock mode will be entered if the clock monitor enable bit (CME) and the self-clock mode
enable bit (SCME) are both asserted and the clock monitor in the oscillator block detects a loss of
clock. As soon as self-clock mode is entered the CRGV4 starts to perform a clock quality check.
Self-clock mode remains active until the clock quality check indicates that the required quality of
the incoming clock signal is met (frequency and amplitude). Self-clock mode should be used for
safety purposes only. It provides reduced functionality to the MCU in case a loss of clock is causing
severe system conditions.
9.1.3 Block Diagram
Figure 9-1 shows a block diagram of the CRGV4.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 253
Rev 01.24
Figure 9-1. CRG Block Diagram
9.2 External Signal Description
This section lists and describes the signals that connect off chip.
9.2.1 VDDPLL, VSSPLL — PLL Operating Voltage, PLL Ground
These pins provides operating voltage (VDDPLL) and ground (VSSPLL) for the PLL circuitry. This allows
the supply voltage to the PLL to be independently bypassed. Even if PLL usage is not required VDDPLL
and VSSPLL must be connected properly.
9.2.2 XFC — PLL Loop Filter Pin
A passive external loop filter must be placed on the XFC pin. The filter is a second-order, low-pass filter
to eliminate the VCO input ripple. The value of the external filter network and the reference frequency
determines the speed of the corrections and the stability of the PLL. Refer to the device overview chapter
for calculation of PLL loop filter (XFC) components. If PLL usage is not required the XFC pin must be
tied to VDDPLL.
CRG
Registers
Clock and Reset
COP
RESET
RTI
PLL
XFC
VDDPLL
VSSPLL
Oscil-
EXTAL
XTAL
Control
Bus Clock
System Reset
Oscillator Clock
PLLCLK
OSCCLK
Core Clock
Clock
Monitor
CM fail
Clock Quality
Checker
Reset
Generator
XCLKS
Power-on Reset
Low Voltage Reset 1
COP Timeout
Real-Time Interrupt
PLL Lock Interrupt
Self-Clock Mode
Interrupt
lator
Voltage
Regulator
1 Refer to the device overview section for availability of the low-voltage reset feature.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
254 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 9-2. PLL Loop Filter Connections
9.2.3 RESET — Reset Pin
RESET is an active low bidirectional reset pin. As an input it initializes the MCU asynchronously to a
known start-up state. As an open-drain output it indicates that an system reset (internal to MCU) has been
triggered.
9.3 Memory Map and Register Definition
This section provides a detailed description of all registers accessible in the CRGV4.
9.3.1 Module Memory Map
Table 9-1 gives an overview on all CRGV4 registers.
Table 9-1. CRGV4 Memory Map
Address
Offset Use Access
0x0000 CRG Synthesizer Register (SYNR) R/W
0x0001 CRG Reference Divider Register (REFDV) R/W
0x0002 CRG Test Flags Register (CTFLG)(1)
1. CTFLG is intended for factory test purposes only.
R/W
0x0003 CRG Flags Register (CRGFLG) R/W
0x0004 CRG Interrupt Enable Register (CRGINT) R/W
0x0005 CRG Clock Select Register (CLKSEL) R/W
0x0006 CRG PLL Control Register (PLLCTL) R/W
0x0007 CRG RTI Control Register (RTICTL) R/W
0x0008 CRG COP Control Register (COPCTL) R/W
0x0009 CRG Force and Bypass Test Register (FORBYP)(2)
2. FORBYP is intended for factory test purposes only.
R/W
0x000A CRG Test Control Register (CTCTL)(3)
3. CTCTL is intended for factory test purposes only.
R/W
0x000B CRG COP Arm/Timer Reset (ARMCOP) R/W
MCU
XFC
RS
CS
VDDPLL
CP
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 255
Rev 01.24
NOTE
Register address = base address + address offset, where the base address is
defined at the MCU level and the address offset is defined at the module
level.
9.3.2 Register Descriptions
This section describes in address order all the CRGV4 registers and their individual bits.
Register
Name Bit 7 654321Bit 0
0x0000
SYNR
R0 0 SYN5 SYN4 SYN3 SYN2 SYN1 SYN0
W
0x0001
REFDV
R0000
REFDV3 REFDV2 REFDV1 REFDV0
W
0x0002
CTFLG
R00000000
W
0x0003
CRGFLG
RRTIF PORF LVRF LOCKIF LOCK TRACK SCMIF SCM
W
0x0004
CRGINT
RRTIE 00
LOCKIE 00
SCMIE 0
W
0x0005
CLKSEL
RPLLSEL PSTP SYSWAI ROAWAI PLLWAI CWAI RTIWAI COPWAI
W
0x0006
PLLCTL
RCME PLLON AUTO ACQ 0PRE PCE SCME
W
0x0007
RTICTL
R0 RTR6 RTR5 RTR4 RTR3 RTR2 RTR1 RTR0
W
0x0008
COPCTL
RWCOP RSBCK 000
CR2 CR1 CR0
W
0x0009
FORBYP
R00000000
W
0x000A
CTCTL
R00000000
W
= Unimplemented or Reserved
Figure 9-3. CRG Register Summary
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
256 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.3.2.1 CRG Synthesizer Register (SYNR)
The SYNR register controls the multiplication factor of the PLL. If the PLL is on, the count in the loop
divider (SYNR) register effectively multiplies up the PLL clock (PLLCLK) from the reference frequency
by 2 x (SYNR+1). PLLCLK will not be below the minimum VCO frequency (fSCM).
NOTE
If PLL is selected (PLLSEL=1), Bus Clock = PLLCLK / 2
Bus Clock must not exceed the maximum operating system frequency.
Read: anytime
Write: anytime except if PLLSEL = 1
NOTE
Write to this register initializes the lock detector bit and the track detector
bit.
0x000B
ARMCOP
R00000000
W Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Module Base + 0x0000
76543210
R0 0
SYN5 SYNR SYN3 SYN2 SYN1 SYN0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-4. CRG Synthesizer Register (SYNR)
Register
Name Bit 7 654321Bit 0
= Unimplemented or Reserved
Figure 9-3. CRG Register Summary (continued)
PLLCLK 2xOSCCLKx SYNR 1+()
REFDV 1+()
----------------------------------
=
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 257
Rev 01.24
9.3.2.2 CRG Reference Divider Register (REFDV)
The REFDV register provides a finer granularity for the PLL multiplier steps. The count in the reference
divider divides OSCCLK frequency by REFDV + 1.
Read: anytime
Write: anytime except when PLLSEL = 1
NOTE
Write to this register initializes the lock detector bit and the track detector
bit.
9.3.2.3 Reserved Register (CTFLG)
This register is reserved for factory testing of the CRGV4 module and is not available in normal modes.
Read: always reads 0x0000 in normal modes
Write: unimplemented in normal modes
NOTE
Writing to this register when in special mode can alter the CRGV4
functionality.
Module Base + 0x0001
76543210
R0000
REFDV3 REFDV2 REFDV1 REFDV0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-5. CRG Reference Divider Register (REFDV)
Module Base + 0x0002
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-6. CRG Reserved Register (CTFLG)
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
258 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.3.2.4 CRG Flags Register (CRGFLG)
This register provides CRG status bits and flags.
Read: anytime
Write: refer to each bit for individual write conditions
Module Base + 0x0003
76543210
R
RTIF PORF LVRF LOCKIF
LOCK TRACK
SCMIF
SCM
W
Reset 0 Note 1 Note 2 00000
1. PORF is set to 1 when a power-on reset occurs. Unaffected by system reset.
2. LVRF is set to 1 when a low-voltage reset occurs. Unaffected by system reset.
= Unimplemented or Reserved
Figure 9-7. CRG Flag Register (CRGFLG)
Table 9-2. CRGFLG Field Descriptions
Field Description
7
RTIF
Real-Time Interrupt Flag — RTIF is set to 1 at the end of the RTI period. This flag can only be cleared by writing
a 1. Writing a 0 has no effect. If enabled (RTIE = 1), RTIF causes an interrupt request.
0 RTI time-out has not yet occurred.
1 RTI time-out has occurred.
6
PORF
Power-on Reset Flag — PORF is set to 1 when a power-on reset occurs. This flag can only be cleared by writing
a 1. Writing a 0 has no effect.
0 Power-on reset has not occurred.
1 Power-on reset has occurred.
5
LVRF
Low-Voltage Reset Flag — If low voltage reset feature is not available (see the device overview chapter), LVRF
always reads 0. LVRF is set to 1 when a low voltage reset occurs. This flag can only be cleared by writing a 1.
Writing a 0 has no effect.
0 Low voltage reset has not occurred.
1 Low voltage reset has occurred.
4
LOCKIF
PLL Lock Interrupt Flag — LOCKIF is set to 1 when LOCK status bit changes. This flag can only be cleared by
writing a 1. Writing a 0 has no effect.If enabled (LOCKIE = 1), LOCKIF causes an interrupt request.
0 No change in LOCK bit.
1 LOCK bit has changed.
3
LOCK
Lock Status Bit — LOCK reflects the current state of PLL lock condition. This bit is cleared in self-clock mode.
Writes have no effect.
0 PLL VCO is not within the desired tolerance of the target frequency.
1 PLL VCO is within the desired tolerance of the target frequency.
2
TRACK
Track Status Bit — TRACK reflects the current state of PLL track condition. This bit is cleared in self-clock mode.
Writes have no effect.
0 Acquisition mode status.
1 Tracking mode status.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 259
Rev 01.24
9.3.2.5 CRG Interrupt Enable Register (CRGINT)
This register enables CRG interrupt requests.
Read: anytime
Write: anytime
1
SCMIF
Self-Clock Mode Interrupt Flag — SCMIF is set to 1 when SCM status bit changes. This flag can only be
cleared by writing a 1. Writing a 0 has no effect. If enabled (SCMIE=1), SCMIF causes an interrupt request.
0 No change in SCM bit.
1 SCM bit has changed.
0
SCM
Self-Clock Mode Status Bit — SCM reflects the current clocking mode. Writes have no effect.
0 MCU is operating normally with OSCCLK available.
1 MCU is operating in self-clock mode with OSCCLK in an unknown state. All clocks are derived from PLLCLK
running at its minimum frequency fSCM.
Module Base + 0x0004
76543210
R
RTIE
00
LOCKIE
00
SCMIE
0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-8. CRG Interrupt Enable Register (CRGINT)
Table 9-3. CRGINT Field Descriptions
Field Description
7
RTIE
Real-Time Interrupt Enable Bit
0 Interrupt requests from RTI are disabled.
1 Interrupt will be requested whenever RTIF is set.
4
LOCKIE
Lock Interrupt Enable Bit
0 LOCK interrupt requests are disabled.
1 Interrupt will be requested whenever LOCKIF is set.
1
SCMIE
Self-Clock Mode Interrupt Enable Bit
0 SCM interrupt requests are disabled.
1 Interrupt will be requested whenever SCMIF is set.
Table 9-2. CRGFLG Field Descriptions (continued)
Field Description
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
260 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.3.2.6 CRG Clock Select Register (CLKSEL)
This register controls CRG clock selection. Refer to Figure 9-17 for details on the effect of each bit.
Read: anytime
Write: refer to each bit for individual write conditions
Module Base + 0x0005
76543210
R
PLLSEL PSTP SYSWAI ROAWAI PLLWAI CWAI RTIWAI COPWAI
W
Reset 0 0 0 00000
Figure 9-9. CRG Clock Select Register (CLKSEL)
Table 9-4. CLKSEL Field Descriptions
Field Description
7
PLLSEL
PLL Select Bit — Write anytime. Writing a 1 when LOCK = 0 and AUTO = 1, or TRACK = 0 and AUTO = 0 has
no effect. This prevents the selection of an unstable PLLCLK as SYSCLK. PLLSEL bit is cleared when the MCU
enters self-clock mode, stop mode or wait mode with PLLWAI bit set.
0 System clocks are derived from OSCCLK (Bus Clock = OSCCLK / 2).
1 System clocks are derived from PLLCLK (Bus Clock = PLLCLK / 2).
6
PSTP
Pseudo-Stop Bit — Write: anytime — This bit controls the functionality of the oscillator during stop mode.
0 Oscillator is disabled in stop mode.
1 Oscillator continues to run in stop mode (pseudo-stop). The oscillator amplitude is reduced. Refer to oscillator
block description for availability of a reduced oscillator amplitude.
Note: Pseudo-stop allows for faster stop recovery and reduces the mechanical stress and aging of the resonator
in case of frequent stop conditions at the expense of a slightly increased power consumption.
Note: Lower oscillator amplitude exhibits lower power consumption but could have adverse effects during any
electro-magnetic susceptibility (EMS) tests.
5
SYSWAI
System Clocks Stop in Wait Mode Bit — Write: anytime
0 In wait mode, the system clocks continue to run.
1 In wait mode, the system clocks stop.
Note: RTI and COP are not affected by SYSWAI bit.
4
ROAWAI
Reduced Oscillator Amplitude in Wait Mode Bit — Write: anytime — Refer to oscillator block description
chapter for availability of a reduced oscillator amplitude. If no such feature exists in the oscillator block then
setting this bit to 1 will not have any effect on power consumption.
0 Normal oscillator amplitude in wait mode.
1 Reduced oscillator amplitude in wait mode.
Note: Lower oscillator amplitude exhibits lower power consumption but could have adverse effects during any
electro-magnetic susceptibility (EMS) tests.
3
PLLWAI
PLL Stops in Wait Mode Bit — Write: anytime — If PLLWAI is set, the CRGV4 will clear the PLLSEL bit before
entering wait mode. The PLLON bit remains set during wait mode but the PLL is powered down. Upon exiting
wait mode, the PLLSEL bit has to be set manually if PLL clock is required.
While the PLLWAI bit is set the AUTO bit is set to 1 in order to allow the PLL to automatically lock on the selected
target frequency after exiting wait mode.
0 PLL keeps running in wait mode.
1 PLL stops in wait mode.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 261
Rev 01.24
9.3.2.7 CRG PLL Control Register (PLLCTL)
This register controls the PLL functionality.
Read: anytime
Write: refer to each bit for individual write conditions
2
CWAI
Core Stops in Wait Mode Bit — Write: anytime
0 Core clock keeps running in wait mode.
1 Core clock stops in wait mode.
1
RTIWAI
RTI Stops in Wait Mode Bit — Write: anytime
0 RTI keeps running in wait mode.
1 RTI stops and initializes the RTI dividers whenever the part goes into wait mode.
0
COPWAI
COP Stops in Wait Mode Bit — Normal modes: Write once —Special modes: Write anytime
0 COP keeps running in wait mode.
1 COP stops and initializes the COP dividers whenever the part goes into wait mode.
Module Base + 0x0006
76543210
R
CME PLLON AUTO ACQ
0
PRE PCE SCME
W
Reset 1 1 1 10001
= Unimplemented or Reserved
Figure 9-10. CRG PLL Control Register (PLLCTL)
Table 9-5. PLLCTL Field Descriptions
Field Description
7
CME
Clock Monitor Enable Bit — CME enables the clock monitor. Write anytime except when SCM = 1.
0 Clock monitor is disabled.
1 Clock monitor is enabled. Slow or stopped clocks will cause a clock monitor reset sequence or self-clock
mode.
Note: Operating with CME = 0 will not detect any loss of clock. In case of poor clock quality this could cause
unpredictable operation of the MCU.
Note: In Stop Mode (PSTP = 0) the clock monitor is disabled independently of the CME bit setting and any loss
of clock will not be detected.
6
PLLON
Phase Lock Loop On Bit — PLLON turns on the PLL circuitry. In self-clock mode, the PLL is turned on, but the
PLLON bit reads the last latched value. Write anytime except when PLLSEL = 1.
0 PLL is turned off.
1 PLL is turned on. If AUTO bit is set, the PLL will lock automatically.
Table 9-4. CLKSEL Field Descriptions (continued)
Field Description
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
262 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.3.2.8 CRG RTI Control Register (RTICTL)
This register selects the timeout period for the real-time interrupt.
Read: anytime
Write: anytime
NOTE
A write to this register initializes the RTI counter.
5
AUTO
Automatic Bandwidth Control Bit — AUTO selects either the high bandwidth (acquisition) mode or the low
bandwidth (tracking) mode depending on how close to the desired frequency the VCO is running. Write anytime
except when PLLWAI=1, because PLLWAI sets the AUTO bit to 1.
0 Automatic mode control is disabled and the PLL is under software control, using ACQ bit.
1 Automatic mode control is enabled and ACQ bit has no effect.
4
ACQ
Acquisition Bit — Write anytime. If AUTO=1 this bit has no effect.
0 Low bandwidth filter is selected.
1 High bandwidth filter is selected.
2
PRE
RTI Enable during Pseudo-Stop Bit — PRE enables the RTI during pseudo-stop mode. Write anytime.
0 RTI stops running during pseudo-stop mode.
1 RTI continues running during pseudo-stop mode.
Note: If the PRE bit is cleared the RTI dividers will go static while pseudo-stop mode is active. The RTI dividers
will not initialize like in wait mode with RTIWAI bit set.
1
PCE
COP Enable during Pseudo-Stop Bit — PCE enables the COP during pseudo-stop mode. Write anytime.
0 COP stops running during pseudo-stop mode
1 COP continues running during pseudo-stop mode
Note: If the PCE bit is cleared the COP dividers will go static while pseudo-stop mode is active. The COP dividers
will not initialize like in wait mode with COPWAI bit set.
0
SCME
Self-Clock Mode Enable Bit — Normal modes: Write once —Special modes: Write anytime — SCME can not
be cleared while operating in self-clock mode (SCM=1).
0 Detection of crystal clock failure causes clock monitor reset (see Section 9.5.1, “Clock Monitor Reset”).
1 Detection of crystal clock failure forces the MCU in self-clock mode (see Section 9.4.7.2, “Self-Clock Mode”).
Module Base + 0x0007
76543210
R0
RTR6 RTR5 RTR4 RTR3 RTR2 RTR1 RTR0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-11. CRG RTI Control Register (RTICTL)
Table 9-5. PLLCTL Field Descriptions (continued)
Field Description
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 263
Rev 01.24
Table 9-6. RTICTL Field Descriptions
Field Description
6:4
RTR[6:4]
Real-Time Interrupt Prescale Rate Select Bits — These bits select the prescale rate for the RTI. See Table 9-7.
3:0
RTR[3:0]
Real-Time Interrupt Modulus Counter Select Bits — These bits select the modulus counter target value to
provide additional granularity. Table 9-7 shows all possible divide values selectable by the RTICTL register. The
source clock for the RTI is OSCCLK.
Table 9-7. RTI Frequency Divide Rates
RTR[3:0]
RTR[6:4] =
000
(OFF)
001
(210)
010
(211)
011
(212)
100
(213)
101
(214)
110
(215)
111
(216)
0000 (÷1) OFF*210 211 212 213 214 215 216
0001 (÷2) OFF*2x210 2x211 2x212 2x213 2x214 2x215 2x216
0010 (÷3) OFF*3x210 3x211 3x212 3x213 3x214 3x215 3x216
0011 (÷4) OFF*4x210 4x211 4x212 4x213 4x214 4x215 4x216
0100 (÷5) OFF*5x210 5x211 5x212 5x213 5x214 5x215 5x216
0101 (÷6) OFF*6x210 6x211 6x212 6x213 6x214 6x215 6x216
0110 (÷7) OFF*7x210 7x211 7x212 7x213 7x214 7x215 7x216
0111 (÷8) OFF*8x210 8x211 8x212 8x213 8x214 8x215 8x216
1000 (÷9) OFF*9x210 9x211 9x212 9x213 9x214 9x215 9x216
1001 (÷10) OFF*10x210 10x211 10x212 10x213 10x214 10x215 10x216
1010 (÷11) OFF*11x210 11x211 11x212 11x213 11x214 11x215 11x216
1011 (÷12) OFF*12x210 12x211 12x212 12x213 12x214 12x215 12x216
1100 (÷13) OFF*13x210 13x211 13x212 13x213 13x214 13x215 13x216
1101 (÷14) OFF*14x210 14x211 14x212 14x213 14x214 14x215 14x216
1110 (÷15) OFF*15x210 15x211 15x212 15x213 15x214 15x215 15x216
1111 (÷16) OFF*16x210 16x211 16x212 16x213 16x214 16x215 16x216
* Denotes the default value out of reset.This value should be used to disable the RTI to ensure future backwards compatibility.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
264 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.3.2.9 CRG COP Control Register (COPCTL)
This register controls the COP (computer operating properly) watchdog.
Read: anytime
Write: WCOP, CR2, CR1, CR0: once in user mode, anytime in special mode
Write: RSBCK: once
Module Base + 0x0008
76543210
RWCOP RSBCK 000
CR2 CR1 CR0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-12. CRG COP Control Register (COPCTL)
Table 9-8. COPCTL Field Descriptions
Field Description
7
WCOP
Window COP Mode Bit — When set, a write to the ARMCOP register must occur in the last 25% of the selected
period. A write during the first 75% of the selected period will reset the part. As long as all writes occur during
this window, 0x0055 can be written as often as desired. As soon as 0x00AA is written after the 0x0055, the time-
out logic restarts and the user must wait until the next window before writing to ARMCOP. Table 9-9 shows the
exact duration of this window for the seven available COP rates.
0 Normal COP operation
1 Window COP operation
6
RSBCK
COP and RTI Stop in Active BDM Mode Bit
0 Allows the COP and RTI to keep running in active BDM mode.
1 Stops the COP and RTI counters whenever the part is in active BDM mode.
2:0
CR[2:0]
COP Watchdog Timer Rate Select — These bits select the COP time-out rate (see Table 9-9). The COP time-
out period is OSCCLK period divided by CR[2:0] value. Writing a nonzero value to CR[2:0] enables the COP
counter and starts the time-out period. A COP counter time-out causes a system reset. This can be avoided by
periodically (before time-out) reinitializing the COP counter via the ARMCOP register.
Table 9-9. COP Watchdog Rates(1)
1. OSCCLK cycles are referenced from the previous COP time-out reset
(writing 0x0055/0x00AA to the ARMCOP register)
CR2 CR1 CR0 OSCCLK
Cycles to Time Out
0 0 0 COP disabled
001 2
14
010 2
16
011 2
18
100 2
20
101 2
22
110 2
23
111 2
24
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 265
Rev 01.24
9.3.2.10 Reserved Register (FORBYP)
NOTE
This reserved register is designed for factory test purposes only, and is not
intended for general user access. Writing to this register when in special
modes can alter the CRG’s functionality.
Read: always read 0x0000 except in special modes
Write: only in special modes
9.3.2.11 Reserved Register (CTCTL)
NOTE
This reserved register is designed for factory test purposes only, and is not
intended for general user access. Writing to this register when in special test
modes can alter the CRG’s functionality.
Read: always read 0x0080 except in special modes
Write: only in special modes
Module Base + 0x0009
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-13. Reserved Register (FORBYP)
Module Base + 0x000A
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 9-14. Reserved Register (CTCTL)
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
266 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.3.2.12 CRG COP Timer Arm/Reset Register (ARMCOP)
This register is used to restart the COP time-out period.
Read: always reads 0x0000
Write: anytime
When the COP is disabled (CR[2:0] = “000”) writing to this register has no effect.
When the COP is enabled by setting CR[2:0] nonzero, the following applies:
Writing any value other than 0x0055 or 0x00AA causes a COP reset. To restart the COP time-out
period you must write 0x0055 followed by a write of 0x00AA. Other instructions may be executed
between these writes but the sequence (0x0055, 0x00AA) must be completed prior to COP end of
time-out period to avoid a COP reset. Sequences of 0x0055 writes or sequences of 0x00AA writes
are allowed. When the WCOP bit is set, 0x0055 and 0x00AA writes must be done in the last 25%
of the selected time-out period; writing any value in the first 75% of the selected period will cause
a COP reset.
9.4 Functional Description
This section gives detailed informations on the internal operation of the design.
9.4.1 Phase Locked Loop (PLL)
The PLL is used to run the MCU from a different time base than the incoming OSCCLK. For increased
flexibility, OSCCLK can be divided in a range of 1 to 16 to generate the reference frequency. This offers
a finer multiplication granularity. The PLL can multiply this reference clock by a multiple of 2, 4, 6,...
126,128 based on the SYNR register.
CAUTION
Although it is possible to set the two dividers to command a very high clock
frequency, do not exceed the specified bus frequency limit for the MCU.
If (PLLSEL = 1), Bus Clock = PLLCLK / 2
Module Base + 0x000B
76543210
R00000000
W Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 0 0 0 00000
Figure 9-15. ARMCOP Register Diagram
PLLCLK 2 OSCCLK SYNR 1+[]
REFDV 1+[]
----------------------------------
××=
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 267
Rev 01.24
The PLL is a frequency generator that operates in either acquisition mode or tracking mode, depending on
the difference between the output frequency and the target frequency. The PLL can change between
acquisition and tracking modes either automatically or manually.
The VCO has a minimum operating frequency, which corresponds to the self-clock mode frequency fSCM.
Figure 9-16. PLL Functional Diagram
9.4.1.1 PLL Operation
The oscillator output clock signal (OSCCLK) is fed through the reference programmable divider and is
divided in a range of 1 to 16 (REFDV+1) to output the reference clock. The VCO output clock, (PLLCLK)
is fed back through the programmable loop divider and is divided in a range of 2 to 128 in increments of
[2 x (SYNR +1)] to output the feedback clock. See Figure 9-16.
The phase detector then compares the feedback clock, with the reference clock. Correction pulses are
generated based on the phase difference between the two signals. The loop filter then slightly alters the DC
voltage on the external filter capacitor connected to XFC pin, based on the width and direction of the
correction pulse. The filter can make fast or slow corrections depending on its mode, as described in the
next subsection. The values of the external filter network and the reference frequency determine the speed
of the corrections and the stability of the PLL.
9.4.1.2 Acquisition and Tracking Modes
The lock detector compares the frequencies of the feedback clock, and the reference clock. Therefore, the
speed of the lock detector is directly proportional to the final reference frequency. The circuit determines
the mode of the PLL and the lock condition based on this comparison.
REDUCED
CONSUMPTION
OSCILLATOR
EXTAL
XTAL
OSCCLK
PLLCLK
REFERENCE
PROGRAMMABLE
DIVIDER PDET
PHASE
DETECTOR
REFDV <3:0>
LOOP
PROGRAMMABLE
DIVIDER
SYN <5:0>
CPUMP VCO
LOCK
LOOP
FILTER
XFC
PIN
UP
DOWN
LOCK
DETECTOR
REFERENCE
FEEDBACK
VDDPLL
VDDPLL/VSSPLL
CRYSTAL
MONITOR
VDDPLL/VSSPLL
VDD/VSS
supplied by:
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
268 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The PLL filter can be manually or automatically configured into one of two possible operating modes:
• Acquisition mode
In acquisition mode, the filter can make large frequency corrections to the VCO. This mode is used
at PLL start-up or when the PLL has suffered a severe noise hit and the VCO frequency is far off
the desired frequency. When in acquisition mode, the TRACK status bit is cleared in the CRGFLG
register.
• Tracking mode
In tracking mode, the filter makes only small corrections to the frequency of the VCO. PLL jitter
is much lower in tracking mode, but the response to noise is also slower. The PLL enters tracking
mode when the VCO frequency is nearly correct and the TRACK bit is set in the CRGFLG register.
The PLL can change the bandwidth or operational mode of the loop filter manually or automatically.
In automatic bandwidth control mode (AUTO = 1), the lock detector automatically switches between
acquisition and tracking modes. Automatic bandwidth control mode also is used to determine when the
PLL clock (PLLCLK) is safe to use as the source for the system and core clocks. If PLL LOCK interrupt
requests are enabled, the software can wait for an interrupt request and then check the LOCK bit. If CPU
interrupts are disabled, software can poll the LOCK bit continuously (during PLL start-up, usually) or at
periodic intervals. In either case, only when the LOCK bit is set, is the PLLCLK clock safe to use as the
source for the system and core clocks. If the PLL is selected as the source for the system and core clocks
and the LOCK bit is clear, the PLL has suffered a severe noise hit and the software must take appropriate
action, depending on the application.
The following conditions apply when the PLL is in automatic bandwidth control mode (AUTO = 1):
• The TRACK bit is a read-only indicator of the mode of the filter.
• The TRACK bit is set when the VCO frequency is within a certain tolerance, ∆trk, and is clear when
the VCO frequency is out of a certain tolerance, ∆unt.
• The LOCK bit is a read-only indicator of the locked state of the PLL.
• The LOCK bit is set when the VCO frequency is within a certain tolerance, ∆Lock, and is cleared
when the VCO frequency is out of a certain tolerance, ∆unl.
• CPU interrupts can occur if enabled (LOCKIE = 1) when the lock condition changes, toggling the
LOCK bit.
The PLL can also operate in manual mode (AUTO = 0). Manual mode is used by systems that do not
require an indicator of the lock condition for proper operation. Such systems typically operate well below
the maximum system frequency (fsys) and require fast start-up. The following conditions apply when in
manual mode:
• ACQ is a writable control bit that controls the mode of the filter. Before turning on the PLL in
manual mode, the ACQ bit should be asserted to configure the filter in acquisition mode.
• After turning on the PLL by setting the PLLON bit software must wait a given time (tacq) before
entering tracking mode (ACQ = 0).
• After entering tracking mode software must wait a given time (tal) before selecting the PLLCLK
as the source for system and core clocks (PLLSEL = 1).
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 269
Rev 01.24
9.4.2 System Clocks Generator
Figure 9-17. System Clocks Generator
The clock generator creates the clocks used in the MCU (see Figure 9-17). The gating condition placed on
top of the individual clock gates indicates the dependencies of different modes (stop, wait) and the setting
of the respective configuration bits.
The peripheral modules use the bus clock. Some peripheral modules also use the oscillator clock. The
memory blocks use the bus clock. If the MCU enters self-clock mode (see Section 9.4.7.2, “Self-Clock
Mode”), oscillator clock source is switched to PLLCLK running at its minimum frequency fSCM. The bus
clock is used to generate the clock visible at the ECLK pin. The core clock signal is the clock for the CPU.
The core clock is twice the bus clock as shown in Figure 9-18. But note that a CPU cycle corresponds to
one bus clock.
PLL clock mode is selected with PLLSEL bit in the CLKSEL register. When selected, the PLL output
clock drives SYSCLK for the main system including the CPU and peripherals. The PLL cannot be turned
off by clearing the PLLON bit, if the PLL clock is selected. When PLLSEL is changed, it takes a maximum
OSCILLATOR
PHASE
LOCK
LOOP
EXTAL
XTAL
SYSCLK
RTI
OSCCLK
PLLCLK
CLOCK PHASE
GENERATOR
Bus Clock
Clock
Monitor
1
0
PLLSEL or SCM
÷2
Core Clock
COP
Oscillator
Oscillator
= Clock Gate
Gating
Condition
WAIT(CWAI,SYSWAI),
STOP
WAIT(RTIWAI),
STOP(PSTP,PRE),
RTI enable
WAIT(COPWAI),
STOP(PSTP,PCE),
COP enable
WAIT(SYSWAI),
STOP
STOP(PSTP)
1
0
SCM
WAIT(SYSWAI),
STOP
Clock
Clock
(running during
Pseudo-Stop Mode
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
270 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
of 4 OSCCLK plus 4 PLLCLK cycles to make the transition. During the transition, all clocks freeze and
CPU activity ceases.
Figure 9-18. Core Clock and Bus Clock Relationship
9.4.3 Clock Monitor (CM)
If no OSCCLK edges are detected within a certain time, the clock monitor within the oscillator block
generates a clock monitor fail event. The CRGV4 then asserts self-clock mode or generates a system reset
depending on the state of SCME bit. If the clock monitor is disabled or the presence of clocks is detected
no failure is indicated by the oscillator block.The clock monitor function is enabled/disabled by the CME
control bit.
9.4.4 Clock Quality Checker
The clock monitor performs a coarse check on the incoming clock signal. The clock quality checker
provides a more accurate check in addition to the clock monitor.
A clock quality check is triggered by any of the following events:
• Power-on reset (POR)
• Low voltage reset (LVR)
• Wake-up from full stop mode (exit full stop)
• Clock monitor fail indication (CM fail)
A time window of 50000 VCO clock cycles1 is called check window.
A number greater equal than 4096 rising OSCCLK edges within a check window is called osc ok. Note that
osc ok immediately terminates the current check window. See Figure 9-19 as an example.
Figure 9-19. Check Window Example
1. VCO clock cycles are generated by the PLL when running at minimum frequency fSCM.
CORE CLOCK:
BUS CLOCK / ECLK
12 49999 50000
VCO
clock
check window
12345
4095
4096
3
OSCCLK
osc ok
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 271
Rev 01.24
The sequence for clock quality check is shown in Figure 9-20.
Figure 9-20. Sequence for Clock Quality Check
NOTE
Remember that in parallel to additional actions caused by self-clock mode
or clock monitor reset1 handling the clock quality checker continues to
check the OSCCLK signal.
NOTE
The clock quality checker enables the PLL and the voltage regulator
(VREG) anytime a clock check has to be performed. An ongoing clock
quality check could also cause a running PLL (fSCM) and an active VREG
during pseudo-stop mode or wait mode
1. A Clock Monitor Reset will always set the SCME bit to logical’1’
check window
osc ok
?
SCM
active? Switch to OSCCLK
Exit SCM
Clock OK
num=0
num<50
?
num=num+1
yes
no
yes
SCME=1
?
no
Enter SCM
SCM
active?
yes
Clock Monitor Reset
no
yes
no
num=50
yes
no
POR exit full stop
CM fail
LVR
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
272 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.4.5 Computer Operating Properly Watchdog (COP)
Figure 9-21. Clock Chain for COP
The COP (free running watchdog timer) enables the user to check that a program is running and
sequencing properly. The COP is disabled out of reset. When the COP is being used, software is
responsible for keeping the COP from timing out. If the COP times out it is an indication that the software
is no longer being executed in the intended sequence; thus a system reset is initiated (see Section 9.5.2,
“Computer Operating Properly Watchdog (COP) Reset).” The COP runs with a gated OSCCLK (see
Section Figure 9-21., “Clock Chain for COP”). Three control bits in the COPCTL register allow selection
of seven COP time-out periods.
When COP is enabled, the program must write 0x0055 and 0x00AA (in this order) to the ARMCOP
register during the selected time-out period. As soon as this is done, the COP time-out period is restarted.
If the program fails to do this and the COP times out, the part will reset. Also, if any value other than
0x0055 or 0x00AA is written, the part is immediately reset.
Windowed COP operation is enabled by setting WCOP in the COPCTL register. In this mode, writes to
the ARMCOP register to clear the COP timer must occur in the last 25% of the selected time-out period.
A premature write will immediately reset the part.
If PCE bit is set, the COP will continue to run in pseudo-stop mode.
9.4.6 Real-Time Interrupt (RTI)
The RTI can be used to generate a hardware interrupt at a fixed periodic rate. If enabled (by setting
RTIE=1), this interrupt will occur at the rate selected by the RTICTL register. The RTI runs with a gated
OSCCLK (see Section Figure 9-22., “Clock Chain for RTI”). At the end of the RTI time-out period the
RTIF flag is set to 1 and a new RTI time-out period starts immediately.
A write to the RTICTL register restarts the RTI time-out period.
OSCCLK
CR[2:0]
COP TIMEOUT
0:0:0
0:0:1
0:1:0
0:1:1
1:0:0
1:0:1
1:1:0
1:1:1
÷ 4
÷ 4
÷ 2
÷ 4
÷ 2
÷
16384
÷
4
CR[2:0]
= Clock Gate
WAIT(COPWAI),
STOP(PSTP,PCE),
COP enable
gating condition
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 273
Rev 01.24
If the PRE bit is set, the RTI will continue to run in pseudo-stop mode.
.
Figure 9-22. Clock Chain for RTI
9.4.7 Modes of Operation
9.4.7.1 Normal Mode
The CRGV4 block behaves as described within this specification in all normal modes.
9.4.7.2 Self-Clock Mode
The VCO has a minimum operating frequency, fSCM. If the external clock frequency is not available due
to a failure or due to long crystal start-up time, the bus clock and the core clock are derived from the VCO
running at minimum operating frequency; this mode of operation is called self-clock mode. This requires
CME = 1 and SCME = 1. If the MCU was clocked by the PLL clock prior to entering self-clock mode, the
PLLSEL bit will be cleared. If the external clock signal has stabilized again, the CRG will automatically
select OSCCLK to be the system clock and return to normal mode. See Section 9.4.4, “Clock Quality
Checker” for more information on entering and leaving self-clock mode.
OSCCLK
RTR[6:4]
0:0:0
0:0:1
0:1:0
0:1:1
1:0:0
1:0:1
1:1:0
1:1:1
÷ 2
÷ 2
÷ 2
÷ 2
÷ 2
÷ 2
COUNTER (RTR[3:0])
4-BIT MODULUS
÷ 1024
RTI TIMEOUT
= Clock Gate
WAIT(RTIWAI),
STOP(PSTP,PRE),
RTI enable
gating condition
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
274 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
NOTE
In order to detect a potential clock loss, the CME bit should be always
enabled (CME=1).
If CME bit is disabled and the MCU is configured to run on PLL clock
(PLLCLK), a loss of external clock (OSCCLK) will not be detected and will
cause the system clock to drift towards the VCO’s minimum frequency
fSCM. As soon as the external clock is available again the system clock
ramps up to its PLL target frequency. If the MCU is running on external
clock any loss of clock will cause the system to go static.
9.4.8 Low-Power Operation in Run Mode
The RTI can be stopped by setting the associated rate select bits to 0.
The COP can be stopped by setting the associated rate select bits to 0.
9.4.9 Low-Power Operation in Wait Mode
The WAI instruction puts the MCU in a low power consumption stand-by mode depending on setting of
the individual bits in the CLKSEL register. All individual wait mode configuration bits can be superposed.
This provides enhanced granularity in reducing the level of power consumption during wait mode. Table 9-
10 lists the individual configuration bits and the parts of the MCU that are affected in wait mode.
After executing the WAI instruction the core requests the CRG to switch MCU into wait mode. The CRG
then checks whether the PLLWAI, CWAI and SYSWAI bits are asserted (see Figure 9-23). Depending on
the configuration the CRG switches the system and core clocks to OSCCLK by clearing the PLLSEL bit,
disables the PLL, disables the core clocks and finally disables the remaining system clocks. As soon as all
clocks are switched off wait mode is active.
Table 9-10. MCU Configuration During Wait Mode
PLLWAI CWAI SYSWAI RTIWAI COPWAI ROAWAI
PLL stopped —————
Core — stopped stopped — — —
System — — stopped — — —
RTI — — — stopped — —
COP ————stopped —
Oscillator —————reduced(1)
1. Refer to oscillator block description for availability of a reduced oscillator amplitude.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 275
Rev 01.24
Figure 9-23. Wait Mode Entry/Exit Sequence
Enter
Wait Mode
PLLWAI=1
?
Exit Wait w.
CMRESET
Exit Wait w.
ext.RESET
Exit
Wait Mode
Enter
SCM
Exit
Wait Mode
Core req’s
Wait Mode.
CWAI or
SYSWAI=1
?
SYSWAI=1
?
Clear
PLLSEL,
Disable PLL
Disable
core clocks
Disable
system clocks CME=1
?
INT
?
CM fail
?
SCME=1
?
SCMIE=1
?
Continue w.
normal OP
no
no
no
no
no
no
no
yes
yes
yes
yes
yes
no
yes
yes
yes
Wait Mode left
due to external
reset
Generate
SCM Interrupt
(Wakeup from Wait) SCM=1
?
Enter
SCM
no
yes
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
276 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
There are five different scenarios for the CRG to restart the MCU from wait mode:
• External reset
• Clock monitor reset
• COP reset
• Self-clock mode interrupt
• Real-time interrupt (RTI)
If the MCU gets an external reset during wait mode active, the CRG asynchronously restores all
configuration bits in the register space to its default settings and starts the reset generator. After completing
the reset sequence processing begins by fetching the normal reset vector. Wait mode is exited and the MCU
is in run mode again.
If the clock monitor is enabled (CME=1) the MCU is able to leave wait mode when loss of
oscillator/external clock is detected by a clock monitor fail. If the SCME bit is not asserted the CRG
generates a clock monitor fail reset (CMRESET). The CRG’s behavior for CMRESET is the same
compared to external reset, but another reset vector is fetched after completion of the reset sequence. If the
SCME bit is asserted the CRG generates a SCM interrupt if enabled (SCMIE=1). After generating the
interrupt the CRG enters self-clock mode and starts the clock quality checker (see Section 9.4.4, “Clock
Quality Checker”). Then the MCU continues with normal operation.If the SCM interrupt is blocked by
SCMIE = 0, the SCMIF flag will be asserted and clock quality checks will be performed but the MCU will
not wake-up from wait mode.
If any other interrupt source (e.g. RTI) triggers exit from wait mode the MCU immediately continues with
normal operation. If the PLL has been powered-down during wait mode the PLLSEL bit is cleared and the
MCU runs on OSCCLK after leaving wait mode. The software must manually set the PLLSEL bit again,
in order to switch system and core clocks to the PLLCLK.
If wait mode is entered from self-clock mode, the CRG will continue to check the clock quality until clock
check is successful. The PLL and voltage regulator (VREG) will remain enabled.
Table 9-11 summarizes the outcome of a clock loss while in wait mode.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 277
Rev 01.24
Table 9-11. Outcome of Clock Loss in Wait Mode
CME SCME SCMIE CRG Actions
0 X X Clock failure -->
No action, clock loss not detected.
1 0 X Clock failure -->
CRG performs Clock Monitor Reset immediately
1 1 0 Clock failure -->
Scenario 1: OSCCLK recovers prior to exiting Wait Mode.
– MCU remains in Wait Mode,
– VREG enabled,
– PLL enabled,
– SCM activated,
– Start Clock Quality Check,
– Set SCMIF interrupt flag.
Some time later OSCCLK recovers.
– CM no longer indicates a failure,
– 4096 OSCCLK cycles later Clock Quality Check indicates clock o.k.,
– SCM deactivated,
– PLL disabled depending on PLLWAI,
– VREG remains enabled (never gets disabled in Wait Mode).
– MCU remains in Wait Mode.
Some time later either a wakeup interrupt occurs (no SCM interrupt)
– Exit Wait Mode using OSCCLK as system clock (SYSCLK),
– Continue normal operation.
or an External Reset is applied.
– Exit Wait Mode using OSCCLK as system clock,
– Start reset sequence.
Scenario 2: OSCCLK does not recover prior to exiting Wait Mode.
– MCU remains in Wait Mode,
– VREG enabled,
– PLL enabled,
– SCM activated,
– Start Clock Quality Check,
– Set SCMIF interrupt flag,
– Keep performing Clock Quality Checks (could continue infinitely)
while in Wait Mode.
Some time later either a wakeup interrupt occurs (no SCM interrupt)
– Exit Wait Mode in SCM using PLL clock (fSCM) as system clock,
– Continue to perform additional Clock Quality Checks until OSCCLK
is o.k. again.
or an External RESET is applied.
– Exit Wait Mode in SCM using PLL clock (fSCM) as system clock,
– Start reset sequence,
– Continue to perform additional Clock Quality Checks until OSCCLK
is o.k.again.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
278 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.4.10 Low-Power Operation in Stop Mode
All clocks are stopped in STOP mode, dependent of the setting of the PCE, PRE and PSTP bit. The
oscillator is disabled in STOP mode unless the PSTP bit is set. All counters and dividers remain frozen but
do not initialize. If the PRE or PCE bits are set, the RTI or COP continues to run in pseudo-stop mode. In
addition to disabling system and core clocks the CRG requests other functional units of the MCU (e.g.
voltage-regulator) to enter their individual power-saving modes (if available). This is the main difference
between pseudo-stop mode and wait mode.
After executing the STOP instruction the core requests the CRG to switch the MCU into stop mode. If the
PLLSEL bit remains set when entering stop mode, the CRG will switch the system and core clocks to
OSCCLK by clearing the PLLSEL bit. Then the CRG disables the PLL, disables the core clock and finally
disables the remaining system clocks. As soon as all clocks are switched off, stop mode is active.
If pseudo-stop mode (PSTP = 1) is entered from self-clock mode the CRG will continue to check the clock
quality until clock check is successful. The PLL and the voltage regulator (VREG) will remain enabled. If
full stop mode (PSTP = 0) is entered from self-clock mode an ongoing clock quality check will be stopped.
A complete timeout window check will be started when stop mode is exited again.
Wake-up from stop mode also depends on the setting of the PSTP bit.
1 1 1 Clock failure -->
– VREG enabled,
– PLL enabled,
– SCM activated,
– Start Clock Quality Check,
– SCMIF set.
SCMIF generates Self-Clock Mode wakeup interrupt.
– Exit Wait Mode in SCM using PLL clock (fSCM) as system clock,
– Continue to perform a additional Clock Quality Checks until OSCCLK
is o.k. again.
Table 9-11. Outcome of Clock Loss in Wait Mode (continued)
CME SCME SCMIE CRG Actions
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 279
Rev 01.24
Figure 9-24. Stop Mode Entry/Exit Sequence
9.4.10.1 Wake-Up from Pseudo-Stop (PSTP=1)
Wake-up from pseudo-stop is the same as wake-up from wait mode. There are also three different scenarios
for the CRG to restart the MCU from pseudo-stop mode:
• External reset
• Clock monitor fail
• Wake-up interrupt
Exit Stop w.
CMRESET
Exit
Stop Mode
Enter
SCM
Exit
Stop Mode
Core req’s
Stop Mode.
Clear
PLLSEL,
Disable PLL
CME=1
?
INT
?
CM fail
?
SCME=1
?
SCMIE=1
?
Continue w.
normal OP
no
no
no
no
yes
yes
yes
yes
yes
Generate
SCM Interrupt
(Wakeup from Stop)
Enter
Stop Mode
Exit Stop w.
ext.RESET
Wait Mode left
due to external
Clock
OK
?
SCME=1
?
Enter
SCM
yes
no
yes
Exit Stop w.
CMRESET
no
no
no PSTP=1
?
INT
?
yesno
yes
Exit
Stop Mode
Exit
Stop Mode
SCM=1
?
Enter
SCM
no
yes
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
280 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
If the MCU gets an external reset during pseudo-stop mode active, the CRG asynchronously restores all
configuration bits in the register space to its default settings and starts the reset generator. After completing
the reset sequence processing begins by fetching the normal reset vector. Pseudo-stop mode is exited and
the MCU is in run mode again.
If the clock monitor is enabled (CME = 1) the MCU is able to leave pseudo-stop mode when loss of
oscillator/external clock is detected by a clock monitor fail. If the SCME bit is not asserted the CRG
generates a clock monitor fail reset (CMRESET). The CRG’s behavior for CMRESET is the same
compared to external reset, but another reset vector is fetched after completion of the reset sequence. If the
SCME bit is asserted the CRG generates a SCM interrupt if enabled (SCMIE=1). After generating the
interrupt the CRG enters self-clock mode and starts the clock quality checker (see Section 9.4.4, “Clock
Quality Checker”). Then the MCU continues with normal operation. If the SCM interrupt is blocked by
SCMIE = 0, the SCMIF flag will be asserted but the CRG will not wake-up from pseudo-stop mode.
If any other interrupt source (e.g. RTI) triggers exit from pseudo-stop mode the MCU immediately
continues with normal operation. Because the PLL has been powered-down during stop mode the PLLSEL
bit is cleared and the MCU runs on OSCCLK after leaving stop mode. The software must set the PLLSEL
bit again, in order to switch system and core clocks to the PLLCLK.
Table 9-12 summarizes the outcome of a clock loss while in pseudo-stop mode.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 281
Rev 01.24
Table 9-12. Outcome of Clock Loss in Pseudo-Stop Mode
CME SCME SCMIE CRG Actions
0 X X Clock failure -->
No action, clock loss not detected.
1 0 X Clock failure -->
CRG performs Clock Monitor Reset immediately
1 1 0 Clock Monitor failure -->
Scenario 1: OSCCLK recovers prior to exiting Pseudo-Stop Mode.
– MCU remains in Pseudo-Stop Mode,
– VREG enabled,
– PLL enabled,
– SCM activated,
– Start Clock Quality Check,
– Set SCMIF interrupt flag.
Some time later OSCCLK recovers.
– CM no longer indicates a failure,
– 4096 OSCCLK cycles later Clock Quality Check indicates clock o.k.,
– SCM deactivated,
– PLL disabled,
– VREG disabled.
– MCU remains in Pseudo-Stop Mode.
Some time later either a wakeup interrupt occurs (no SCM interrupt)
– Exit Pseudo-Stop Mode using OSCCLK as system clock (SYSCLK),
– Continue normal operation.
or an External Reset is applied.
– Exit Pseudo-Stop Mode using OSCCLK as system clock,
– Start reset sequence.
Scenario 2: OSCCLK does not recover prior to exiting Pseudo-Stop Mode.
– MCU remains in Pseudo-Stop Mode,
– VREG enabled,
– PLL enabled,
– SCM activated,
– Start Clock Quality Check,
– Set SCMIF interrupt flag,
– Keep performing Clock Quality Checks (could continue infinitely)
while in Pseudo-Stop Mode.
Some time later either a wakeup interrupt occurs (no SCM interrupt)
– Exit Pseudo-Stop Mode in SCM using PLL clock (fSCM) as system clock
– Continue to perform additional Clock Quality Checks until OSCCLK
is o.k. again.
or an External RESET is applied.
– Exit Pseudo-Stop Mode in SCM using PLL clock (fSCM) as system clock
– Start reset sequence,
– Continue to perform additional Clock Quality Checks until OSCCLK
is o.k.again.
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
282 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.4.10.2 Wake-up from Full Stop (PSTP=0)
The MCU requires an external interrupt or an external reset in order to wake-up from stop mode.
If the MCU gets an external reset during full stop mode active, the CRG asynchronously restores all
configuration bits in the register space to its default settings and will perform a maximum of 50 clock
check_windows (see Section 9.4.4, “Clock Quality Checker”). After completing the clock quality check
the CRG starts the reset generator. After completing the reset sequence processing begins by fetching the
normal reset vector. Full stop mode is exited and the MCU is in run mode again.
If the MCU is woken-up by an interrupt, the CRG will also perform a maximum of 50 clock
check_windows (see Section 9.4.4, “Clock Quality Checker”). If the clock quality check is successful, the
CRG will release all system and core clocks and will continue with normal operation. If all clock checks
within the timeout-window are failing, the CRG will switch to self-clock mode or generate a clock monitor
reset (CMRESET) depending on the setting of the SCME bit.
Because the PLL has been powered-down during stop mode the PLLSEL bit is cleared and the MCU runs
on OSCCLK after leaving stop mode. The software must manually set the PLLSEL bit again, in order to
switch system and core clocks to the PLLCLK.
NOTE
In full stop mode, the clock monitor is disabled and any loss of clock will
not be detected.
9.5 Resets
This section describes how to reset the CRGV4 and how the CRGV4 itself controls the reset of the MCU.
It explains all special reset requirements. Because the reset generator for the MCU is part of the CRG, this
section also describes all automatic actions that occur during or as a result of individual reset conditions.
The reset values of registers and signals are provided in Section 9.3, “Memory Map and Register
1 1 1 Clock failure -->
– VREG enabled,
– PLL enabled,
– SCM activated,
– Start Clock Quality Check,
– SCMIF set.
SCMIF generates Self-Clock Mode wakeup interrupt.
– Exit Pseudo-Stop Mode in SCM using PLL clock (fSCM) as system clock,
– Continue to perform a additional Clock Quality Checks until OSCCLK
is o.k. again.
Table 9-12. Outcome of Clock Loss in Pseudo-Stop Mode (continued)
CME SCME SCMIE CRG Actions
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 283
Rev 01.24
Definition.” All reset sources are listed in Table 9-13. Refer to the device overview chapter for related
vector addresses and priorities.
The reset sequence is initiated by any of the following events:
• Low level is detected at the RESET pin (external reset).
• Power on is detected.
• Low voltage is detected.
• COP watchdog times out.
• Clock monitor failure is detected and self-clock mode was disabled (SCME = 0).
Upon detection of any reset event, an internal circuit drives the RESET pin low for 128 SYSCLK cycles
(see Figure 9-25). Because entry into reset is asynchronous it does not require a running SYSCLK.
However, the internal reset circuit of the CRGV4 cannot sequence out of current reset condition without a
running SYSCLK. The number of 128 SYSCLK cycles might be increased by n = 3 to 6 additional
SYSCLK cycles depending on the internal synchronization latency. After 128+n SYSCLK cycles the
RESET pin is released. The reset generator of the CRGV4 waits for additional 64 SYSCLK cycles and
then samples the RESET pin to determine the originating source. Table 9-14 shows which vector will be
fetched.
NOTE
External circuitry connected to the RESET pin should not include a large
capacitance that would interfere with the ability of this signal to rise to a
valid logic 1 within 64 SYSCLK cycles after the low drive is released.
Table 9-13. Reset Summary
Reset Source Local Enable
Power-on Reset None
Low Voltage Reset None
External Reset None
Clock Monitor Reset PLLCTL (CME=1, SCME=0)
COP Watchdog Reset COPCTL (CR[2:0] nonzero)
Table 9-14. Reset Vector Selection
Sampled RESET Pin
(64 Cycles After
Release)
Clock Monitor
Reset Pending
COP Reset
Pending Vector Fetch
1 0 0 POR / LVR / External Reset
1 1 X Clock Monitor Reset
1 0 1 COP Reset
0 X X POR / LVR / External Reset
with rise of RESET pin
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
284 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The internal reset of the MCU remains asserted while the reset generator completes the 192 SYSCLK long
reset sequence. The reset generator circuitry always makes sure the internal reset is deasserted
synchronously after completion of the 192 SYSCLK cycles. In case the RESET pin is externally driven
low for more than these 192 SYSCLK cycles (external reset), the internal reset remains asserted too.
Figure 9-25. RESET Timing
9.5.1 Clock Monitor Reset
The CRGV4 generates a clock monitor reset in case all of the following conditions are true:
• Clock monitor is enabled (CME=1)
• Loss of clock is detected
• Self-clock mode is disabled (SCME=0)
The reset event asynchronously forces the configuration registers to their default settings (see Section 9.3,
“Memory Map and Register Definition”). In detail the CME and the SCME are reset to logical ‘1’ (which
doesn’t change the state of the CME bit, because it has already been set). As a consequence, the CRG
immediately enters self-clock mode and starts its internal reset sequence. In parallel the clock quality
check starts. As soon as clock quality check indicates a valid oscillator clock the CRG switches to
OSCCLK and leaves self-clock mode. Because the clock quality checker is running in parallel to the reset
generator, the CRG may leave self-clock mode while completing the internal reset sequence. When the
reset sequence is finished the CRG checks the internally latched state of the clock monitor fail circuit. If a
clock monitor fail is indicated processing begins by fetching the clock monitor reset vector.
9.5.2 Computer Operating Properly Watchdog (COP) Reset
When COP is enabled, the CRG expects sequential write of 0x0055 and 0x00AA (in this order) to the
ARMCOP register during the selected time-out period. As soon as this is done, the COP time-out period
restarts. If the program fails to do this the CRG will generate a reset. Also, if any value other than 0x0055
or 0x00AA is written, the CRG immediately generates a reset. In case windowed COP operation is enabled
) ( ) (
)
(
)
SYSCLK
128+n cycles 64 cycles
with nbeing
min 3 / max 6
cycles depending
on internal
synchronization
delay
CRG drives RESET pin low
possibly
SYSCLK
not
running
possibly
RESET
driven low
externally
)
(
(
RESET
RESET pin
released
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 285
Rev 01.24
writes (0x0055 or 0x00AA) to the ARMCOP register must occur in the last 25% of the selected time-out
period. A premature write the CRG will immediately generate a reset.
As soon as the reset sequence is completed the reset generator checks the reset condition. If no clock
monitor failure is indicated and the latched state of the COP timeout is true, processing begins by fetching
the COP vector.
9.5.3 Power-On Reset, Low Voltage Reset
The on-chip voltage regulator detects when VDD to the MCU has reached a certain level and asserts power-
on reset or low voltage reset or both. As soon as a power-on reset or low voltage reset is triggered the CRG
performs a quality check on the incoming clock signal. As soon as clock quality check indicates a valid
oscillator clock signal the reset sequence starts using the oscillator clock. If after 50 check windows the
clock quality check indicated a non-valid oscillator clock the reset sequence starts using self-clock mode.
Figure 9-26 and Figure 9-27 show the power-up sequence for cases when the RESET pin is tied to VDD
and when the RESET pin is held low.
Figure 9-26. RESET Pin Tied to VDD (by a Pull-Up Resistor)
Figure 9-27. RESET Pin Held Low Externally
RESET
Internal POR
128 SYSCLK
64 SYSCLK
Internal RESET
Clock Quality Check
(no Self-Clock Mode)
) (
) (
) (
Clock Quality Check
RESET
Internal POR
Internal RESET
128 SYSCLK
64 SYSCLK
(no Self-Clock Mode)
) (
) (
) (
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
286 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
9.6 Interrupts
The interrupts/reset vectors requested by the CRG are listed in Table 9-15. Refer to the device overview
chapter for related vector addresses and priorities.
9.6.1 Real-Time Interrupt
The CRGV4 generates a real-time interrupt when the selected interrupt time period elapses. RTI interrupts
are locally disabled by setting the RTIE bit to 0. The real-time interrupt flag (RTIF) is set to 1 when a
timeout occurs, and is cleared to 0 by writing a 1 to the RTIF bit.
The RTI continues to run during pseudo-stop mode if the PRE bit is set to 1. This feature can be used for
periodic wakeup from pseudo-stop if the RTI interrupt is enabled.
9.6.2 PLL Lock Interrupt
The CRGV4 generates a PLL lock interrupt when the LOCK condition of the PLL has changed, either
from a locked state to an unlocked state or vice versa. Lock interrupts are locally disabled by setting the
LOCKIE bit to 0. The PLL Lock interrupt flag (LOCKIF) is set to1 when the LOCK condition has
changed, and is cleared to 0 by writing a 1 to the LOCKIF bit.
9.6.3 Self-Clock Mode Interrupt
The CRGV4 generates a self-clock mode interrupt when the SCM condition of the system has changed,
either entered or exited self-clock mode. SCM conditions can only change if the self-clock mode enable
bit (SCME) is set to 1. SCM conditions are caused by a failing clock quality check after power-on reset
(POR) or low voltage reset (LVR) or recovery from full stop mode (PSTP = 0) or clock monitor failure.
For details on the clock quality check refer to Section 9.4.4, “Clock Quality Checker.” If the clock monitor
is enabled (CME = 1) a loss of external clock will also cause a SCM condition (SCME = 1).
SCM interrupts are locally disabled by setting the SCMIE bit to 0. The SCM interrupt flag (SCMIF) is set
to 1 when the SCM condition has changed, and is cleared to 0 by writing a 1 to the SCMIF bit.
Table 9-15. CRG Interrupt Vectors
Interrupt Source CCR
Mask Local Enable
Real-time interrupt I bit CRGINT (RTIE)
LOCK interrupt I bit CRGINT (LOCKIE)
SCM interrupt I bit CRGINT (SCMIE)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 287
Rev 01.24
Chapter 10
Freescale’s Scalable Controller Area Network
(S12MSCANV2)
10.1 Introduction
Freescale’s scalable controller area network (S12MSCANV2) definition is based on the MSCAN12
definition, which is the specific implementation of the MSCAN concept targeted for the M68HC12
microcontroller family.
The module is a communication controller implementing the CAN 2.0A/B protocol as defined in the
Bosch specification dated September 1991. For users to fully understand the MSCAN specification, it is
recommended that the Bosch specification be read first to familiarize the reader with the terms and
concepts contained within this document.
Though not exclusively intended for automotive applications, CAN protocol is designed to meet the
specific requirements of a vehicle serial data bus: real-time processing, reliable operation in the EMI
environment of a vehicle, cost-effectiveness, and required bandwidth.
MSCAN uses an advanced buffer arrangement resulting in predictable real-time behavior and simplified
application software.
10.1.1 Glossary
ACK: Acknowledge of CAN message
CAN: Controller Area Network
CRC: Cyclic Redundancy Code
EOF: End of Frame
FIFO: First-In-First-Out Memory
IFS: Inter-Frame Sequence
SOF: Start of Frame
CPU bus: CPU related read/write data bus
CAN bus: CAN protocol related serial bus
oscillator clock: Direct clock from external oscillator
bus clock: CPU bus realated clock
CAN clock: CAN protocol related clock
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
288 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.1.2 Block Diagram
Figure 10-1. MSCAN Block Diagram
10.1.3 Features
The basic features of the MSCAN are as follows:
• Implementation of the CAN protocol — Version 2.0A/B
— Standard and extended data frames
— Zero to eight bytes data length
— Programmable bit rate up to 1 Mbps1
— Support for remote frames
• Five receive buffers with FIFO storage scheme
• Three transmit buffers with internal prioritization using a “local priority” concept
• Flexible maskable identifier filter supports two full-size (32-bit) extended identifier filters, or four
16-bit filters, or eight 8-bit filters
• Programmable wakeup functionality with integrated low-pass filter
• Programmable loopback mode supports self-test operation
• Programmable listen-only mode for monitoring of CAN bus
• Separate signalling and interrupt capabilities for all CAN receiver and transmitter error states
(warning, error passive, bus-off)
• Programmable MSCAN clock source either bus clock or oscillator clock
• Internal timer for time-stamping of received and transmitted messages
• Three low-power modes: sleep, power down, and MSCAN enable
• Global initialization of configuration registers
1. Depending on the actual bit timing and the clock jitter of the PLL.
RXCAN
TXCAN
Receive/
Transmit
Engine
Message
Filtering
and
Buffering
Control
and
Status
Wake-Up Interrupt Req.
Errors Interrupt Req.
Receive Interrupt Req.
Transmit Interrupt Req.
CANCLK
Bus Clock
Configuration
Oscillator Clock
MUX
Presc.
Tq Clk
MSCAN
Low Pass Filter
Wake-Up
Registers
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 289
Rev 01.24
10.1.4 Modes of Operation
The following modes of operation are specific to the MSCAN. See Section 10.4, “Functional Description,”
for details.
• Listen-Only Mode
• MSCAN Sleep Mode
• MSCAN Initialization Mode
• MSCAN Power Down Mode
10.2 External Signal Description
The MSCAN uses two external pins:
10.2.1 RXCAN — CAN Receiver Input Pin
RXCAN is the MSCAN receiver input pin.
10.2.2 TXCAN — CAN Transmitter Output Pin
TXCAN is the MSCAN transmitter output pin. The TXCAN output pin represents the logic level on the
CAN bus:
0 = Dominant state
1 = Recessive state
10.2.3 CAN System
A typical CAN system with MSCAN is shown in Figure 10-2. Each CAN station is connected physically
to the CAN bus lines through a transceiver device. The transceiver is capable of driving the large current
needed for the CAN bus and has current protection against defective CAN or defective stations.
Figure 10-2. CAN System
CAN Bus
CAN Controller
(MSCAN)
Transceiver
CAN node 1 CAN node 2 CAN node n
CAN_L
CAN_H
MCU
TXCAN RXCAN
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
290 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3 Memory Map and Register Definition
This section provides a detailed description of all registers accessible in the MSCAN.
10.3.1 Module Memory Map
Figure 10-3 gives an overview on all registers and their individual bits in the MSCAN memory map. The
register address results from the addition of base address and address offset. The base address is
determined at the MCU level and can be found in the MCU memory map description. The address offset
is defined at the module level.
The MSCAN occupies 64 bytes in the memory space. The base address of the MSCAN module is
determined at the MCU level when the MCU is defined. The register decode map is fixed and begins at the
first address of the module address offset.
The detailed register descriptions follow in the order they appear in the register map.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 291
Rev 01.24
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000
CANCTL0
RRXFRM RXACT CSWAI SYNCH TIME WUPE SLPRQ INITRQ
W
0x0001
CANCTL1
RCANE CLKSRC LOOPB LISTEN WUPM SLPAK INITAK
W
0x0002
CANBTR0
RSJW1 SJW0 BRP5 BRP4 BRP3 BRP2 BRP1 BRP0
W
0x0003
CANBTR1
RSAMP TSEG22 TSEG21 TSEG20 TSEG13 TSEG12 TSEG11 TSEG10
W
0x0004
CANRFLG
RWUPIF CSCIF RSTAT1 RSTAT0 TSTAT1 TSTAT0 OVRIF RXF
W
0x0005
CANRIER
RWUPIE CSCIE RSTATE1 RSTATE0 TSTATE1 TSTATE0 OVRIE RXFIE
W
0x0006
CANTFLG
R0 0000
TXE2 TXE1 TXE0
W
0x0007
CANTIER
R00000
TXEIE2 TXEIE1 TXEIE0
W
0x0008
CANTARQ
R00000
ABTRQ2 ABTRQ1 ABTRQ0
W
0x0009
CANTAAK
R00000ABTAK2 ABTAK1 ABTAK0
W
0x000A
CANTBSEL
R00000
TX2 TX1 TX0
W
0x000B
CANIDAC
R0 0 IDAM1 IDAM0 0 IDHIT2 IDHIT1 IDHIT0
W
0x000C–0x000D
Reserved
R00000000
W
0x000E
CANRXERR
R RXERR7 RXERR6 RXERR5 RXERR4 RXERR3 RXERR2 RXERR1 RXERR0
W
0x000F
CANTXERR
R TXERR7 TXERR6 TXERR5 TXERR4 TXERR3 TXERR2 TXERR1 TXERR0
W
= Unimplemented or Reserved u = Unaffected
Figure 10-3. MSCAN Register Summary
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
292 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2 Register Descriptions
This section describes in detail all the registers and register bits in the MSCAN module. Each description
includes a standard register diagram with an associated figure number. Details of register bit and field
function follow the register diagrams, in bit order. All bits of all registers in this module are completely
synchronous to internal clocks during a register read.
10.3.2.1 MSCAN Control Register 0 (CANCTL0)
The CANCTL0 register provides various control bits of the MSCAN module as described below.
0x0010–0x0013
CANIDAR0–3
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
0x0014–0x0017
CANIDMRx
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
0x0018–0x001B
CANIDAR4–7
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
0x001C–0x001F
CANIDMR4–7
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
0x0020–0x002F
CANRXFG
RSee Section 10.3.3, “Programmer’s Model of Message Storage”
W
0x0030–0x003F
CANTXFG
RSee Section 10.3.3, “Programmer’s Model of Message Storage”
W
Module Base + 0x0000
76543210
R
RXFRM
RXACT
CSWAI
SYNCH
TIME WUPE SLPRQ INITRQ
W
Reset: 00000001
= Unimplemented
Figure 10-4. MSCAN Control Register 0 (CANCTL0)
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
= Unimplemented or Reserved u = Unaffected
Figure 10-3. MSCAN Register Summary (continued)
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 293
Rev 01.24
NOTE
The CANCTL0 register, except WUPE, INITRQ, and SLPRQ, is held in the
reset state when the initialization mode is active (INITRQ = 1 and
INITAK = 1). This register is writable again as soon as the initialization
mode is exited (INITRQ = 0 and INITAK = 0).
Read: Anytime
Write: Anytime when out of initialization mode; exceptions are read-only RXACT and SYNCH, RXFRM
(which is set by the module only), and INITRQ (which is also writable in initialization mode).
Table 10-1. CANCTL0 Register Field Descriptions
Field Description
7
RXFRM(1) Received Frame Flag — This bit is read and clear only. It is set when a receiver has received a valid message
correctly, independently of the filter configuration. After it is set, it remains set until cleared by software or reset.
Clearing is done by writing a 1. Writing a 0 is ignored. This bit is not valid in loopback mode.
0 No valid message was received since last clearing this flag
1 A valid message was received since last clearing of this flag
6
RXACT
Receiver Active Status — This read-only flag indicates the MSCAN is receiving a message. The flag is
controlled by the receiver front end. This bit is not valid in loopback mode.
0 MSCAN is transmitting or idle2
1 MSCAN is receiving a message (including when arbitration is lost)(2)
5
CSWAI(3) CAN Stops in Wait Mode — Enabling this bit allows for lower power consumption in wait mode by disabling all
the clocks at the CPU bus interface to the MSCAN module.
0 The module is not affected during wait mode
1 The module ceases to be clocked during wait mode
4
SYNCH
Synchronized Status — This read-only flag indicates whether the MSCAN is synchronized to the CAN bus and
able to participate in the communication process. It is set and cleared by the MSCAN.
0 MSCAN is not synchronized to the CAN bus
1 MSCAN is synchronized to the CAN bus
3
TIME
Timer Enable — This bit activates an internal 16-bit wide free running timer which is clocked by the bit clock rate.
If the timer is enabled, a 16-bit time stamp will be assigned to each transmitted/received message within the
active TX/RX buffer. Right after the EOF of a valid message on the CAN bus, the time stamp is written to the
highest bytes (0x000E, 0x000F) in the appropriate buffer (see Section 10.3.3, “Programmer’s Model of Message
Storage”). The internal timer is reset (all bits set to 0) when disabled. This bit is held low in initialization mode.
0 Disable internal MSCAN timer
1 Enable internal MSCAN timer
2
WUPE(4) Wake-Up Enable — This configuration bit allows the MSCAN to restart from sleep mode when traffic on CAN is
detected (see Section 10.4.5.4, “MSCAN Sleep Mode”).
0 Wake-up disabled — The MSCAN ignores traffic on CAN
1 Wake-up enabled — The MSCAN is able to restart
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
294 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2.2 MSCAN Control Register 1 (CANCTL1)
The CANCTL1 register provides various control bits and handshake status information of the MSCAN
module as described below.
1
SLPRQ(5) Sleep Mode Request — This bit requests the MSCAN to enter sleep mode, which is an internal power saving
mode (see Section 10.4.5.4, “MSCAN Sleep Mode”). The sleep mode request is serviced when the CAN bus is
idle, i.e., the module is not receiving a message and all transmit buffers are empty. The module indicates entry
to sleep mode by setting SLPAK = 1 (see Section 10.3.2.2, “MSCAN Control Register 1 (CANCTL1)”). SLPRQ
cannot be set while the WUPIF flag is set (see Section 10.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”).
Sleep mode will be active until SLPRQ is cleared by the CPU or, depending on the setting of WUPE, the MSCAN
detects activity on the CAN bus and clears SLPRQ itself.
0 Running — The MSCAN functions normally
1 Sleep mode request — The MSCAN enters sleep mode when CAN bus idle
0
INITRQ(6),(7) Initialization Mode Request — When this bit is set by the CPU, the MSCAN skips to initialization mode (see
Section 10.4.5.5, “MSCAN Initialization Mode”). Any ongoing transmission or reception is aborted and
synchronization to the CAN bus is lost. The module indicates entry to initialization mode by setting INITAK = 1
(Section 10.3.2.2, “MSCAN Control Register 1 (CANCTL1)”).
The following registers enter their hard reset state and restore their default values: CANCTL0(8), CANRFLG(9),
CANRIER(10), CANTFLG, CANTIER, CANTARQ, CANTAAK, and CANTBSEL.
The registers CANCTL1, CANBTR0, CANBTR1, CANIDAC, CANIDAR0-7, and CANIDMR0-7 can only be
written by the CPU when the MSCAN is in initialization mode (INITRQ = 1 and INITAK = 1). The values of the
error counters are not affected by initialization mode.
When this bit is cleared by the CPU, the MSCAN restarts and then tries to synchronize to the CAN bus. If the
MSCAN is not in bus-off state, it synchronizes after 11 consecutive recessive bits on the CAN bus; if the MSCAN
is in bus-off state, it continues to wait for 128 occurrences of 11 consecutive recessive bits.
Writing to other bits in CANCTL0, CANRFLG, CANRIER, CANTFLG, or CANTIER must be done only after
initialization mode is exited, which is INITRQ = 0 and INITAK = 0.
0 Normal operation
1 MSCAN in initialization mode
1. The MSCAN must be in normal mode for this bit to become set.
2. See the Bosch CAN 2.0A/B specification for a detailed definition of transmitter and receiver states.
3. In order to protect from accidentally violating the CAN protocol, the TXCAN pin is immediately forced to a recessive state when
the CPU enters wait (CSWAI = 1) or stop mode (see Section 10.4.5.2, “Operation in Wait Mode” and Section 10.4.5.3,
“Operation in Stop Mode”).
4. The CPU has to make sure that the WUPE register and the WUPIE wake-up interrupt enable register (see Section 10.3.2.6,
“MSCAN Receiver Interrupt Enable Register (CANRIER)) is enabled, if the recovery mechanism from stop or wait is required.
5. The CPU cannot clear SLPRQ before the MSCAN has entered sleep mode (SLPRQ = 1 and SLPAK = 1).
6. The CPU cannot clear INITRQ before the MSCAN has entered initialization mode (INITRQ = 1 and INITAK = 1).
7. In order to protect from accidentally violating the CAN protocol, the TXCAN pin is immediately forced to a recessive state when
the initialization mode is requested by the CPU. Thus, the recommended procedure is to bring the MSCAN into sleep mode
(SLPRQ = 1 and SLPAK = 1) before requesting initialization mode.
8. Not including WUPE, INITRQ, and SLPRQ.
9. TSTAT1 and TSTAT0 are not affected by initialization mode.
10. RSTAT1 and RSTAT0 are not affected by initialization mode.
Table 10-1. CANCTL0 Register Field Descriptions (continued)
Field Description
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 295
Rev 01.24
Read: Anytime
Write: Anytime when INITRQ = 1 and INITAK = 1, except CANE which is write once in normal and
anytime in special system operation modes when the MSCAN is in initialization mode (INITRQ = 1 and
INITAK = 1).
Module Base + 0x0001
7 654 3 210
R
CANE CLKSRC LOOPB LISTEN WUPM
SLPAK INITAK
W
Reset: 0 0 0 1 0 0 0 1
= Unimplemented
Figure 10-5. MSCAN Control Register 1 (CANCTL1)
Table 10-2. CANCTL1 Register Field Descriptions
Field Description
7
CANE
MSCAN Enable
0 MSCAN module is disabled
1 MSCAN module is enabled
6
CLKSRC
MSCAN Clock Source — This bit defines the clock source for the MSCAN module (only for systems with a clock
generation module; Section 10.4.3.2, “Clock System,” and Section Figure 10-42., “MSCAN Clocking Scheme,”).
0 MSCAN clock source is the oscillator clock
1 MSCAN clock source is the bus clock
5
LOOPB
Loopback Self Test Mode — When this bit is set, the MSCAN performs an internal loopback which can be used
for self test operation. The bit stream output of the transmitter is fed back to the receiver internally. The RXCAN
input pin is ignored and the TXCAN output goes to the recessive state (logic 1). The MSCAN behaves as it does
normally when transmitting and treats its own transmitted message as a message received from a remote node.
In this state, the MSCAN ignores the bit sent during the ACK slot in the CAN frame acknowledge field to ensure
proper reception of its own message. Both transmit and receive interrupts are generated.
0 Loopback self test disabled
1 Loopback self test enabled
4
LISTEN
Listen Only Mode — This bit configures the MSCAN as a CAN bus monitor. When LISTEN is set, all valid CAN
messages with matching ID are received, but no acknowledgement or error frames are sent out (see
Section 10.4.4.4, “Listen-Only Mode”). In addition, the error counters are frozen. Listen only mode supports
applications which require “hot plugging” or throughput analysis. The MSCAN is unable to transmit any
messages when listen only mode is active.
0 Normal operation
1 Listen only mode activated
2
WUPM
Wake-Up Mode — If WUPE in CANCTL0 is enabled, this bit defines whether the integrated low-pass filter is
applied to protect the MSCAN from spurious wake-up (see Section 10.4.5.4, “MSCAN Sleep Mode”).
0 MSCAN wakes up on any dominant level on the CAN bus
1 MSCAN wakes up only in case of a dominant pulse on the CAN bus that has a length of Twup
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
296 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
1
SLPAK
Sleep Mode Acknowledge — This flag indicates whether the MSCAN module has entered sleep mode (see
Section 10.4.5.4, “MSCAN Sleep Mode”). It is used as a handshake flag for the SLPRQ sleep mode request.
Sleep mode is active when SLPRQ = 1 and SLPAK = 1. Depending on the setting of WUPE, the MSCAN will
clear the flag if it detects activity on the CAN bus while in sleep mode.
0 Running — The MSCAN operates normally
1 Sleep mode active — The MSCAN has entered sleep mode
0
INITAK
Initialization Mode Acknowledge — This flag indicates whether the MSCAN module is in initialization mode
(see Section 10.4.5.5, “MSCAN Initialization Mode”). It is used as a handshake flag for the INITRQ initialization
mode request. Initialization mode is active when INITRQ = 1 and INITAK = 1. The registers CANCTL1,
CANBTR0, CANBTR1, CANIDAC, CANIDAR0–CANIDAR7, and CANIDMR0–CANIDMR7 can be written only by
the CPU when the MSCAN is in initialization mode.
0 Running — The MSCAN operates normally
1 Initialization mode active — The MSCAN has entered initialization mode
Table 10-2. CANCTL1 Register Field Descriptions (continued)
Field Description
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 297
Rev 01.24
10.3.2.3 MSCAN Bus Timing Register 0 (CANBTR0)
The CANBTR0 register configures various CAN bus timing parameters of the MSCAN module.
Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
Module Base + 0x0002
76543210
R
SJW1 SJW0 BRP5 BRP4 BRP3 BRP2 BRP1 BRP0
W
Reset: 00000000
Figure 10-6. MSCAN Bus Timing Register 0 (CANBTR0)
Table 10-3. CANBTR0Register Field Descriptions
Field Description
7:6
SJW[1:0]
Synchronization Jump Width — The synchronization jump width defines the maximum number of time quanta
(Tq) clock cycles a bit can be shortened or lengthened to achieve resynchronization to data transitions on the
CAN bus (see Table 10-4).
5:0
BRP[5:0]
Baud Rate Prescaler — These bits determine the time quanta (Tq) clock which is used to build up the bit timing
(see Table 10-5).
Table 10-4. Synchronization Jump Width
SJW1 SJW0 Synchronization Jump Width
0 0 1 Tq clock cycle
0 1 2 Tq clock cycles
1 0 3 Tq clock cycles
1 1 4 Tq clock cycles
Table 10-5. Baud Rate Prescaler
BRP5 BRP4 BRP3 BRP2 BRP1 BRP0 Prescaler value (P)
000000 1
000001 2
000010 3
000011 4
:::::: :
111111 64
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
298 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2.4 MSCAN Bus Timing Register 1 (CANBTR1)
The CANBTR1 register configures various CAN bus timing parameters of the MSCAN module.
Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
Module Base + 0x0003
76543210
R
SAMP TSEG22 TSEG21 TSEG20 TSEG13 TSEG12 TSEG11 TSEG10
W
Reset: 00000000
Figure 10-7. MSCAN Bus Timing Register 1 (CANBTR1)
Table 10-6. CANBTR1 Register Field Descriptions
Field Description
7
SAMP
Sampling — This bit determines the number of CAN bus samples taken per bit time.
0 One sample per bit.
1 Three samples per bit(1).
If SAMP = 0, the resulting bit value is equal to the value of the single bit positioned at the sample point. If
SAMP = 1, the resulting bit value is determined by using majority rule on the three total samples. For higher bit
rates, it is recommended that only one sample is taken per bit time (SAMP = 0).
1. In this case, PHASE_SEG1 must be at least 2 time quanta (Tq).
6:4
TSEG2[2:0]
Time Segment 2 — Time segments within the bit time fix the number of clock cycles per bit time and the location
of the sample point (see Figure 10-43). Time segment 2 (TSEG2) values are programmable as shown in
Table 10-7.
3:0
TSEG1[3:0]
Time Segment 1 — Time segments within the bit time fix the number of clock cycles per bit time and the location
of the sample point (see Figure 10-43). Time segment 1 (TSEG1) values are programmable as shown in
Table 10-8.
Table 10-7. Time Segment 2 Values
TSEG22 TSEG21 TSEG20 Time Segment 2
0 0 0 1 Tq clock cycle(1)
1. This setting is not valid. Please refer to Table 10-34 for valid settings.
0 0 1 2 Tq clock cycles
::: :
1 1 0 7 Tq clock cycles
1 1 1 8 Tq clock cycles
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 299
Rev 01.24
The bit time is determined by the oscillator frequency, the baud rate prescaler, and the number of time
quanta (Tq) clock cycles per bit (as shown in Table 10-7 and Table 10-8).
Eqn. 10-1
10.3.2.5 MSCAN Receiver Flag Register (CANRFLG)
A flag can be cleared only by software (writing a 1 to the corresponding bit position) when the condition
which caused the setting is no longer valid. Every flag has an associated interrupt enable bit in the
CANRIER register.
NOTE
The CANRFLG register is held in the reset state1 when the initialization
mode is active (INITRQ = 1 and INITAK = 1). This register is writable again
as soon as the initialization mode is exited (INITRQ = 0 and INITAK = 0).
Read: Anytime
Write: Anytime when out of initialization mode, except RSTAT[1:0] and TSTAT[1:0] flags which are read-
only; write of 1 clears flag; write of 0 is ignored.
Table 10-8. Time Segment 1 Values
TSEG13 TSEG12 TSEG11 TSEG10 Time segment 1
0 0 0 0 1 Tq clock cycle(1)
1. This setting is not valid. Please refer to Table 10-34 for valid settings.
0 0 0 1 2 Tq clock cycles1
0 0 1 0 3 Tq clock cycles1
0 0 1 1 4 Tq clock cycles
:::: :
1 1 1 0 15 Tq clock cycles
1 1 1 1 16 Tq clock cycles
Module Base + 0x0004
76543210
R
WUPIF CSCIF
RSTAT1 RSTAT0 TSTAT1 TSTAT0
OVRIF RXF
W
Reset: 00000000
= Unimplemented
Figure 10-8. MSCAN Receiver Flag Register (CANRFLG)
1. The RSTAT[1:0], TSTAT[1:0] bits are not affected by initialization mode.
Bit Time Prescaler value()
fCANCLK
------------------------------------------------------1 TimeSegment1 TimeSegment2++()•=
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
300 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 10-9. CANRFLG Register Field Descriptions
Field Description
7
WUPIF
Wake-Up Interrupt Flag — If the MSCAN detects CAN bus activity while in sleep mode (see Section 10.4.5.4,
“MSCAN Sleep Mode,”) and WUPE = 1 in CANTCTL0 (see Section 10.3.2.1, “MSCAN Control Register 0
(CANCTL0)”), the module will set WUPIF. If not masked, a wake-up interrupt is pending while this flag is set.
0 No wake-up activity observed while in sleep mode
1 MSCAN detected activity on the CAN bus and requested wake-up
6
CSCIF
CAN Status Change Interrupt Flag — This flag is set when the MSCAN changes its current CAN bus status
due to the actual value of the transmit error counter (TEC) and the receive error counter (REC). An additional 4-
bit (RSTAT[1:0], TSTAT[1:0]) status register, which is split into separate sections for TEC/REC, informs the system
on the actual CAN bus status (see Section 10.3.2.6, “MSCAN Receiver Interrupt Enable Register (CANRIER)”).
If not masked, an error interrupt is pending while this flag is set. CSCIF provides a blocking interrupt. That
guarantees that the receiver/transmitter status bits (RSTAT/TSTAT) are only updated when no CAN status change
interrupt is pending. If the TECs/RECs change their current value after the CSCIF is asserted, which would cause
an additional state change in the RSTAT/TSTAT bits, these bits keep their status until the current CSCIF interrupt
is cleared again.
0 No change in CAN bus status occurred since last interrupt
1 MSCAN changed current CAN bus status
5:4
RSTAT[1:0]
Receiver Status Bits — The values of the error counters control the actual CAN bus status of the MSCAN. As
soon as the status change interrupt flag (CSCIF) is set, these bits indicate the appropriate receiver related CAN
bus status of the MSCAN. The coding for the bits RSTAT1, RSTAT0 is:
00 RxOK: 0 ≤ receive error counter ≤ 96
01 RxWRN: 96 < receive error counter ≤ 127
10 RxERR: 127 < receive error counter
11 Bus-off(1): transmit error counter > 255
1. Redundant Information for the most critical CAN bus status which is “bus-off”. This only occurs if the Tx error counter exceeds
a number of 255 errors. Bus-off affects the receiver state. As soon as the transmitter leaves its bus-off state the receiver state
skips to RxOK too. Refer also to TSTAT[1:0] coding in this register.
3:2
TSTAT[1:0]
Transmitter Status Bits — The values of the error counters control the actual CAN bus status of the MSCAN.
As soon as the status change interrupt flag (CSCIF) is set, these bits indicate the appropriate transmitter related
CAN bus status of the MSCAN. The coding for the bits TSTAT1, TSTAT0 is:
00 TxOK: 0 ≤transmit error counter ≤ 96
01 TxWRN: 96 < transmit error counter ≤ 127
10 TxERR: 127 < transmit error counter ≤ 255
11 Bus-Off: transmit error counter > 255
1
OVRIF
Overrun Interrupt Flag — This flag is set when a data overrun condition occurs. If not masked, an error interrupt
is pending while this flag is set.
0 No data overrun condition
1 A data overrun detected
0
RXF(2)
2. To ensure data integrity, do not read the receive buffer registers while the RXF flag is cleared. For MCUs with dual CPUs,
reading the receive buffer registers while the RXF flag is cleared may result in a CPU fault condition.
Receive Buffer Full Flag — RXF is set by the MSCAN when a new message is shifted in the receiver FIFO. This
flag indicates whether the shifted buffer is loaded with a correctly received message (matching identifier,
matching cyclic redundancy code (CRC) and no other errors detected). After the CPU has read that message
from the RxFG buffer in the receiver FIFO, the RXF flag must be cleared to release the buffer. A set RXF flag
prohibits the shifting of the next FIFO entry into the foreground buffer (RxFG). If not masked, a receive interrupt
is pending while this flag is set.
0 No new message available within the RxFG
1 The receiver FIFO is not empty. A new message is available in the RxFG
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 301
Rev 01.24
10.3.2.6 MSCAN Receiver Interrupt Enable Register (CANRIER)
This register contains the interrupt enable bits for the interrupt flags described in the CANRFLG register.
NOTE
The CANRIER register is held in the reset state when the initialization mode
is active (INITRQ=1 and INITAK=1). This register is writable when not in
initialization mode (INITRQ=0 and INITAK=0).
The RSTATE[1:0], TSTATE[1:0] bits are not affected by initialization
mode.
Read: Anytime
Write: Anytime when not in initialization mode
Module Base + 0x0005
76543210
R
WUPIE CSCIE RSTATE1 RSTATE0 TSTATE1 TSTATE0 OVRIE RXFIE
W
Reset: 00000000
Figure 10-9. MSCAN Receiver Interrupt Enable Register (CANRIER)
Table 10-10. CANRIER Register Field Descriptions
Field Description
7
WUPIE(1) Wake-Up Interrupt Enable
0 No interrupt request is generated from this event.
1 A wake-up event causes a Wake-Up interrupt request.
6
CSCIE
CAN Status Change Interrupt Enable
0 No interrupt request is generated from this event.
1 A CAN Status Change event causes an error interrupt request.
5:4
RSTATE[1:0]
Receiver Status Change Enable — These RSTAT enable bits control the sensitivity level in which receiver state
changes are causing CSCIF interrupts. Independent of the chosen sensitivity level the RSTAT flags continue to
indicate the actual receiver state and are only updated if no CSCIF interrupt is pending.
00 Do not generate any CSCIF interrupt caused by receiver state changes.
01 Generate CSCIF interrupt only if the receiver enters or leaves “bus-off” state. Discard other receiver state
changes for generating CSCIF interrupt.
10 Generate CSCIF interrupt only if the receiver enters or leaves “RxErr” or “bus-off”(2) state. Discard other
receiver state changes for generating CSCIF interrupt.
11 Generate CSCIF interrupt on all state changes.
3:2
TSTATE[1:0]
Transmitter Status Change Enable — These TSTAT enable bits control the sensitivity level in which transmitter
state changes are causing CSCIF interrupts. Independent of the chosen sensitivity level, the TSTAT flags
continue to indicate the actual transmitter state and are only updated if no CSCIF interrupt is pending.
00 Do not generate any CSCIF interrupt caused by transmitter state changes.
01 Generate CSCIF interrupt only if the transmitter enters or leaves “bus-off” state. Discard other transmitter
state changes for generating CSCIF interrupt.
10 Generate CSCIF interrupt only if the transmitter enters or leaves “TxErr” or “bus-off” state. Discard other
transmitter state changes for generating CSCIF interrupt.
11 Generate CSCIF interrupt on all state changes.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
302 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2.7 MSCAN Transmitter Flag Register (CANTFLG)
The transmit buffer empty flags each have an associated interrupt enable bit in the CANTIER register.
NOTE
The CANTFLG register is held in the reset state when the initialization
mode is active (INITRQ = 1 and INITAK = 1). This register is writable when
not in initialization mode (INITRQ = 0 and INITAK = 0).
Read: Anytime
Write: Anytime for TXEx flags when not in initialization mode; write of 1 clears flag, write of 0 is ignored
1
OVRIE
Overrun Interrupt Enable
0 No interrupt request is generated from this event.
1 An overrun event causes an error interrupt request.
0
RXFIE
Receiver Full Interrupt Enable
0 No interrupt request is generated from this event.
1 A receive buffer full (successful message reception) event causes a receiver interrupt request.
1. WUPIE and WUPE (see Section 10.3.2.1, “MSCAN Control Register 0 (CANCTL0)”) must both be enabled if the recovery
mechanism from stop or wait is required.
2. Bus-off state is defined by the CAN standard (see Bosch CAN 2.0A/B protocol specification: for only transmitters. Because the
only possible state change for the transmitter from bus-off to TxOK also forces the receiver to skip its current state to RxOK,
the coding of the RXSTAT[1:0] flags define an additional bus-off state for the receiver (see Section 10.3.2.5, “MSCAN Receiver
Flag Register (CANRFLG)”).
Module Base + 0x0006
76543210
R0 0000
TXE2 TXE1 TXE0
W
Reset: 00000111
= Unimplemented
Figure 10-10. MSCAN Transmitter Flag Register (CANTFLG)
Table 10-10. CANRIER Register Field Descriptions (continued)
Field Description
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 303
Rev 01.24
10.3.2.8 MSCAN Transmitter Interrupt Enable Register (CANTIER)
This register contains the interrupt enable bits for the transmit buffer empty interrupt flags.
NOTE
The CANTIER register is held in the reset state when the initialization mode
is active (INITRQ = 1 and INITAK = 1). This register is writable when not
in initialization mode (INITRQ = 0 and INITAK = 0).
Read: Anytime
Write: Anytime when not in initialization mode
Table 10-11. CANTFLG Register Field Descriptions
Field Description
2:0
TXE[2:0]
Transmitter Buffer Empty — This flag indicates that the associated transmit message buffer is empty, and thus
not scheduled for transmission. The CPU must clear the flag after a message is set up in the transmit buffer and
is due for transmission. The MSCAN sets the flag after the message is sent successfully. The flag is also set by
the MSCAN when the transmission request is successfully aborted due to a pending abort request (see
Section 10.3.2.9, “MSCAN Transmitter Message Abort Request Register (CANTARQ)”). If not masked, a
transmit interrupt is pending while this flag is set.
Clearing a TXEx flag also clears the corresponding ABTAKx (see Section 10.3.2.10, “MSCAN Transmitter
Message Abort Acknowledge Register (CANTAAK)”). When a TXEx flag is set, the corresponding ABTRQx bit
is cleared (see Section 10.3.2.9, “MSCAN Transmitter Message Abort Request Register (CANTARQ)”).
When listen-mode is active (see Section 10.3.2.2, “MSCAN Control Register 1 (CANCTL1)”) the TXEx flags
cannot be cleared and no transmission is started.
Read and write accesses to the transmit buffer will be blocked, if the corresponding TXEx bit is cleared
(TXEx = 0) and the buffer is scheduled for transmission.
0 The associated message buffer is full (loaded with a message due for transmission)
1 The associated message buffer is empty (not scheduled)
Module Base + 0x0007
76543210
R00000
TXEIE2 TXEIE1 TXEIE0
W
Reset: 00000000
= Unimplemented
Figure 10-11. MSCAN Transmitter Interrupt Enable Register (CANTIER)
Table 10-12. CANTIER Register Field Descriptions
Field Description
2:0
TXEIE[2:0]
Transmitter Empty Interrupt Enable
0 No interrupt request is generated from this event.
1 A transmitter empty (transmit buffer available for transmission) event causes a transmitter empty interrupt
request.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
304 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2.9 MSCAN Transmitter Message Abort Request Register (CANTARQ)
The CANTARQ register allows abort request of queued messages as described below.
NOTE
The CANTARQ register is held in the reset state when the initialization
mode is active (INITRQ = 1 and INITAK = 1). This register is writable when
not in initialization mode (INITRQ = 0 and INITAK = 0).
Read: Anytime
Write: Anytime when not in initialization mode
Module Base + 0x0008
76543210
R00000
ABTRQ2 ABTRQ1 ABTRQ0
W
Reset: 00000000
= Unimplemented
Figure 10-12. MSCAN Transmitter Message Abort Request Register (CANTARQ)
Table 10-13. CANTARQ Register Field Descriptions
Field Description
2:0
ABTRQ[2:0]
Abort Request — The CPU sets the ABTRQx bit to request that a scheduled message buffer (TXEx = 0) be
aborted. The MSCAN grants the request if the message has not already started transmission, or if the
transmission is not successful (lost arbitration or error). When a message is aborted, the associated TXE (see
Section 10.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”) and abort acknowledge flags (ABTAK, see
Section 10.3.2.10, “MSCAN Transmitter Message Abort Acknowledge Register (CANTAAK)”) are set and a
transmit interrupt occurs if enabled. The CPU cannot reset ABTRQx. ABTRQx is reset whenever the associated
TXE flag is set.
0 No abort request
1 Abort request pending
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 305
Rev 01.24
10.3.2.10 MSCAN Transmitter Message Abort Acknowledge Register (CANTAAK)
The CANTAAK register indicates the successful abort of a queued message, if requested by the
appropriate bits in the CANTARQ register.
NOTE
The CANTAAK register is held in the reset state when the initialization
mode is active (INITRQ = 1 and INITAK = 1).
Read: Anytime
Write: Unimplemented for ABTAKx flags
Module Base + 0x0009
76543210
R00000ABTAK2 ABTAK1 ABTAK0
W
Reset: 00000000
= Unimplemented
Figure 10-13. MSCAN Transmitter Message Abort Acknowledge Register (CANTAAK)
Table 10-14. CANTAAK Register Field Descriptions
Field Description
2:0
ABTAK[2:0]
Abort Acknowledge — This flag acknowledges that a message was aborted due to a pending abort request
from the CPU. After a particular message buffer is flagged empty, this flag can be used by the application
software to identify whether the message was aborted successfully or was sent anyway. The ABTAKx flag is
cleared whenever the corresponding TXE flag is cleared.
0 The message was not aborted.
1 The message was aborted.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
306 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2.11 MSCAN Transmit Buffer Selection Register (CANTBSEL)
The CANTBSEL register allows the selection of the actual transmit message buffer, which then will be
accessible in the CANTXFG register space.
NOTE
The CANTBSEL register is held in the reset state when the initialization
mode is active (INITRQ = 1 and INITAK=1). This register is writable when
not in initialization mode (INITRQ = 0 and INITAK = 0).
Read: Find the lowest ordered bit set to 1, all other bits will be read as 0
Write: Anytime when not in initialization mode
The following gives a short programming example of the usage of the CANTBSEL register:
To get the next available transmit buffer, application software must read the CANTFLG register and write
this value back into the CANTBSEL register. In this example Tx buffers TX1 and TX2 are available. The
value read from CANTFLG is therefore 0b0000_0110. When writing this value back to CANTBSEL, the
Tx buffer TX1 is selected in the CANTXFG because the lowest numbered bit set to 1 is at bit position 1.
Reading back this value out of CANTBSEL results in 0b0000_0010, because only the lowest numbered
bit position set to 1 is presented. This mechanism eases the application software the selection of the next
available Tx buffer.
• LDD CANTFLG; value read is 0b0000_0110
• STD CANTBSEL; value written is 0b0000_0110
• LDD CANTBSEL; value read is 0b0000_0010
If all transmit message buffers are deselected, no accesses are allowed to the CANTXFG registers.
Module Base + 0x000A
76543210
R00000
TX2 TX1 TX0
W
Reset: 00000000
= Unimplemented
Figure 10-14. MSCAN Transmit Buffer Selection Register (CANTBSEL)
Table 10-15. CANTBSEL Register Field Descriptions
Field Description
2:0
TX[2:0]
Transmit Buffer Select — The lowest numbered bit places the respective transmit buffer in the CANTXFG
register space (e.g., TX1 = 1 and TX0 = 1 selects transmit buffer TX0; TX1 = 1 and TX0 = 0 selects transmit
buffer TX1). Read and write accesses to the selected transmit buffer will be blocked, if the corresponding TXEx
bit is cleared and the buffer is scheduled for transmission (see Section 10.3.2.7, “MSCAN Transmitter Flag
Register (CANTFLG)”).
0 The associated message buffer is deselected
1 The associated message buffer is selected, if lowest numbered bit
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 307
Rev 01.24
10.3.2.12 MSCAN Identifier Acceptance Control Register (CANIDAC)
The CANIDAC register is used for identifier acceptance control as described below.
Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1), except bits IDHITx, which are read-
only
Module Base + 0x000B
76543210
R0 0
IDAM1 IDAM0
0 IDHIT2 IDHIT1 IDHIT0
W
Reset: 00000000
= Unimplemented
Figure 10-15. MSCAN Identifier Acceptance Control Register (CANIDAC)
Table 10-16. CANIDAC Register Field Descriptions
Field Description
5:4
IDAM[1:0]
Identifier Acceptance Mode — The CPU sets these flags to define the identifier acceptance filter organization
(see Section 10.4.3, “Identifier Acceptance Filter”). Table 10-17 summarizes the different settings. In filter closed
mode, no message is accepted such that the foreground buffer is never reloaded.
2:0
IDHIT[2:0]
Identifier Acceptance Hit Indicator — The MSCAN sets these flags to indicate an identifier acceptance hit (see
Section 10.4.3, “Identifier Acceptance Filter”). Table 10-18 summarizes the different settings.
Table 10-17. Identifier Acceptance Mode Settings
IDAM1 IDAM0 Identifier Acceptance Mode
0 0 Two 32-bit acceptance filters
0 1 Four 16-bit acceptance filters
1 0 Eight 8-bit acceptance filters
1 1 Filter closed
Table 10-18. Identifier Acceptance Hit Indication
IDHIT2 IDHIT1 IDHIT0 Identifier Acceptance Hit
0 0 0 Filter 0 hit
0 0 1 Filter 1 hit
0 1 0 Filter 2 hit
0 1 1 Filter 3 hit
1 0 0 Filter 4 hit
1 0 1 Filter 5 hit
1 1 0 Filter 6 hit
1 1 1 Filter 7 hit
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
308 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The IDHITx indicators are always related to the message in the foreground buffer (RxFG). When a
message gets shifted into the foreground buffer of the receiver FIFO the indicators are updated as well.
10.3.2.13 MSCAN Reserved Registers
These registers are reserved for factory testing of the MSCAN module and is not available in normal
system operation modes.
Read: Always read 0x0000 in normal system operation modes
Write: Unimplemented in normal system operation modes
NOTE
Writing to this register when in special modes can alter the MSCAN
functionality.
10.3.2.14 MSCAN Receive Error Counter (CANRXERR)
This register reflects the status of the MSCAN receive error counter.
Read: Only when in sleep mode (SLPRQ = 1 and SLPAK = 1) or initialization mode (INITRQ = 1 and
INITAK = 1)
Write: Unimplemented
Module Base + 0x000C, 0x000D
76543210
R00000000
W
Reset: 00000000
= Unimplemented
Figure 10-16. MSCAN Reserved Registers
Module Base + 0x000E
76543210
R RXERR7 RXERR6 RXERR5 RXERR4 RXERR3 RXERR2 RXERR1 RXERR0
W
Reset: 00000000
= Unimplemented
Figure 10-17. MSCAN Receive Error Counter (CANRXERR)
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 309
Rev 01.24
NOTE
Reading this register when in any other mode other than sleep or
initialization mode may return an incorrect value. For MCUs with dual
CPUs, this may result in a CPU fault condition.
Writing to this register when in special modes can alter the MSCAN
functionality.
10.3.2.15 MSCAN Transmit Error Counter (CANTXERR)
This register reflects the status of the MSCAN transmit error counter.
Read: Only when in sleep mode (SLPRQ = 1 and SLPAK = 1) or initialization mode (INITRQ = 1 and
INITAK = 1)
Write: Unimplemented
NOTE
Reading this register when in any other mode other than sleep or
initialization mode, may return an incorrect value. For MCUs with dual
CPUs, this may result in a CPU fault condition.
Writing to this register when in special modes can alter the MSCAN
functionality.
Module Base + 0x000F
76543210
R TXERR7 TXERR6 TXERR5 TXERR4 TXERR3 TXERR2 TXERR1 TXERR0
W
Reset: 00000000
= Unimplemented
Figure 10-18. MSCAN Transmit Error Counter (CANTXERR)
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
310 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2.16 MSCAN Identifier Acceptance Registers (CANIDAR0-7)
On reception, each message is written into the background receive buffer. The CPU is only signalled to
read the message if it passes the criteria in the identifier acceptance and identifier mask registers
(accepted); otherwise, the message is overwritten by the next message (dropped).
The acceptance registers of the MSCAN are applied on the IDR0–IDR3 registers (see Section 10.3.3.1,
“Identifier Registers (IDR0–IDR3)”) of incoming messages in a bit by bit manner (see Section 10.4.3,
“Identifier Acceptance Filter”).
For extended identifiers, all four acceptance and mask registers are applied. For standard identifiers, only
the first two (CANIDAR0/1, CANIDMR0/1) are applied.
Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
Module Base + 0x0010 (CANIDAR0)
0x0011 (CANIDAR1)
0x0012 (CANIDAR2)
0x0013 (CANIDAR3)
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
Figure 10-19. MSCAN Identifier Acceptance Registers (First Bank) — CANIDAR0–CANIDAR3
Table 10-19. CANIDAR0–CANIDAR3 Register Field Descriptions
Field Description
7:0
AC[7:0]
Acceptance Code Bits — AC[7:0] comprise a user-defined sequence of bits with which the corresponding bits
of the related identifier register (IDRn) of the receive message buffer are compared. The result of this comparison
is then masked with the corresponding identifier mask register.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 311
Rev 01.24
Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
Module Base + 0x0018 (CANIDAR4)
0x0019 (CANIDAR5)
0x001A (CANIDAR6)
0x001B (CANIDAR7)
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
76543210
RAC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0
W
Reset 00000000
Figure 10-20. MSCAN Identifier Acceptance Registers (Second Bank) — CANIDAR4–CANIDAR7
Table 10-20. CANIDAR4–CANIDAR7 Register Field Descriptions
Field Description
7:0
AC[7:0]
Acceptance Code Bits — AC[7:0] comprise a user-defined sequence of bits with which the corresponding bits
of the related identifier register (IDRn) of the receive message buffer are compared. The result of this comparison
is then masked with the corresponding identifier mask register.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
312 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.2.17 MSCAN Identifier Mask Registers (CANIDMR0–CANIDMR7)
The identifier mask register specifies which of the corresponding bits in the identifier acceptance register
are relevant for acceptance filtering. To receive standard identifiers in 32 bit filter mode, it is required to
program the last three bits (AM[2:0]) in the mask registers CANIDMR1 and CANIDMR5 to “don’t care.”
To receive standard identifiers in 16 bit filter mode, it is required to program the last three bits (AM[2:0])
in the mask registers CANIDMR1, CANIDMR3, CANIDMR5, and CANIDMR7 to “don’t care.”
Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
Module Base + 0x0014 (CANIDMR0)
0x0015 (CANIDMR1)
0x0016 (CANIDMR2)
0x0017 (CANIDMR3)
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
Figure 10-21. MSCAN Identifier Mask Registers (First Bank) — CANIDMR0–CANIDMR3
Table 10-21. CANIDMR0–CANIDMR3 Register Field Descriptions
Field Description
7:0
AM[7:0]
Acceptance Mask Bits — If a particular bit in this register is cleared, this indicates that the corresponding bit in
the identifier acceptance register must be the same as its identifier bit before a match is detected. The message
is accepted if all such bits match. If a bit is set, it indicates that the state of the corresponding bit in the identifier
acceptance register does not affect whether or not the message is accepted.
0 Match corresponding acceptance code register and identifier bits
1 Ignore corresponding acceptance code register bit
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 313
Rev 01.24
Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
Module Base + 0x001C (CANIDMR4)
0x001D (CANIDMR5)
0x001E (CANIDMR6)
0x001F (CANIDMR7)
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
76543210
RAM7 AM6 AM5 AM4 AM3 AM2 AM1 AM0
W
Reset 00000000
Figure 10-22. MSCAN Identifier Mask Registers (Second Bank) — CANIDMR4–CANIDMR7
Table 10-22. CANIDMR4–CANIDMR7 Register Field Descriptions
Field Description
7:0
AM[7:0]
Acceptance Mask Bits — If a particular bit in this register is cleared, this indicates that the corresponding bit in
the identifier acceptance register must be the same as its identifier bit before a match is detected. The message
is accepted if all such bits match. If a bit is set, it indicates that the state of the corresponding bit in the identifier
acceptance register does not affect whether or not the message is accepted.
0 Match corresponding acceptance code register and identifier bits
1 Ignore corresponding acceptance code register bit
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
314 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.3 Programmer’s Model of Message Storage
The following section details the organization of the receive and transmit message buffers and the
associated control registers.
To simplify the programmer interface, the receive and transmit message buffers have the same outline.
Each message buffer allocates 16 bytes in the memory map containing a 13 byte data structure.
An additional transmit buffer priority register (TBPR) is defined for the transmit buffers. Within the last
two bytes of this memory map, the MSCAN stores a special 16-bit time stamp, which is sampled from an
internal timer after successful transmission or reception of a message. This feature is only available for
transmit and receiver buffers, if the TIME bit is set (see Section 10.3.2.1, “MSCAN Control Register 0
(CANCTL0)”).
The time stamp register is written by the MSCAN. The CPU can only read these registers.
Figure 10-23 shows the common 13-byte data structure of receive and transmit buffers for extended
identifiers. The mapping of standard identifiers into the IDR registers is shown in Figure 10-24.
All bits of the receive and transmit buffers are ‘x’ out of reset because of RAM-based implementation1.
All reserved or unused bits of the receive and transmit buffers always read ‘x’.
Table 10-23. Message Buffer Organization
Offset
Address Register Access
0x00X0 Identifier Register 0
0x00X1 Identifier Register 1
0x00X2 Identifier Register 2
0x00X3 Identifier Register 3
0x00X4 Data Segment Register 0
0x00X5 Data Segment Register 1
0x00X6 Data Segment Register 2
0x00X7 Data Segment Register 3
0x00X8 Data Segment Register 4
0x00X9 Data Segment Register 5
0x00XA Data Segment Register 6
0x00XB Data Segment Register 7
0x00XC Data Length Register
0x00XD Transmit Buffer Priority Register(1)
1. Not applicable for receive buffers
0x00XE Time Stamp Register (High Byte)(2)
2. Read-only for CPU
0x00XF Time Stamp Register (Low Byte)(3)
3. Read-only for CPU
1. Exception: The transmit priority registers are 0 out of reset.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 315
Rev 01.24
Read: For transmit buffers, anytime when TXEx flag is set (see Section 10.3.2.7, “MSCAN Transmitter
Flag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see
Section 10.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). For receive buffers,
only when RXF flag is set (see Section 10.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”).
Register
Name Bit 7 654321Bit0
0x00X0
IDR0
RID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21
W
0x00X1
IDR1
RID20 ID19 ID18 SRR (=1) IDE (=1) ID17 ID16 ID15
W
0x00X2
IDR2
RID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7
W
0x00X3
IDR3
RID6 ID5 ID4 ID3 ID2 ID1 ID0 RTR
W
0x00X4
DSR0
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X5
DSR1
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X6
DSR2
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X7
DSR3
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X8
DSR4
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X9
DSR5
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00XA
DSR6
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00XB
DSR7
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00XC
DLR
RDLC3 DLC2 DLC1 DLC0
W
= Unused, always read ‘x’
Figure 10-23. Receive/Transmit Message Buffer — Extended Identifier Mapping
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
316 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Write: For transmit buffers, anytime when TXEx flag is set (see Section 10.3.2.7, “MSCAN Transmitter
Flag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see
Section 10.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). Unimplemented for
receive buffers.
Reset: Undefined (0x00XX) because of RAM-based implementation
10.3.3.1 Identifier Registers (IDR0–IDR3)
The identifier registers for an extended format identifier consist of a total of 32 bits; ID[28:0], SRR, IDE,
and RTR bits. The identifier registers for a standard format identifier consist of a total of 13 bits; ID[10:0],
RTR, and IDE bits.
10.3.3.1.1 IDR0–IDR3 for Extended Identifier Mapping
Register
Name Bit 7 654321Bit 0
IDR0
0x00X0
RID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3
W
IDR1
0x00X1
RID2 ID1 ID0 RTR IDE (=0)
W
IDR2
0x00X2
R
W
IDR3
0x00X3
R
W
= Unused, always read ‘x’
Figure 10-24. Receive/Transmit Message Buffer — Standard Identifier Mapping
Module Base + 0x00X1
76543210
R
ID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21
W
Reset: xxxxxxxx
Figure 10-25. Identifier Register 0 (IDR0) — Extended Identifier Mapping
Table 10-24. IDR0 Register Field Descriptions — Extended
Field Description
7:0
ID[28:21]
Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 317
Rev 01.24
Module Base + 0x00X1
76543210
R
ID20 ID19 ID18 SRR (=1) IDE (=1) ID17 ID16 ID15
W
Reset: xxxxxxxx
Figure 10-26. Identifier Register 1 (IDR1) — Extended Identifier Mapping
Table 10-25. IDR1 Register Field Descriptions — Extended
Field Description
7:5
ID[20:18]
Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number.
4
SRR
Substitute Remote Request — This fixed recessive bit is used only in extended format. It must be set to 1 by
the user for transmission buffers and is stored as received on the CAN bus for receive buffers.
3
IDE
ID Extended — This flag indicates whether the extended or standard identifier format is applied in this buffer. In
the case of a receive buffer, the flag is set as received and indicates to the CPU how to process the buffer
identifier registers. In the case of a transmit buffer, the flag indicates to the MSCAN what type of identifier to send.
0 Standard format (11 bit)
1 Extended format (29 bit)
2:0
ID[17:15]
Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number.
Module Base + 0x00X2
76543210
R
ID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7
W
Reset: xxxxxxxx
Figure 10-27. Identifier Register 2 (IDR2) — Extended Identifier Mapping
Table 10-26. IDR2 Register Field Descriptions — Extended
Field Description
7:0
ID[14:7]
Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
318 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.3.1.2 IDR0–IDR3 for Standard Identifier Mapping
Module Base + 0x00X3
76543210
R
ID6 ID5 ID4 ID3 ID2 ID1 ID0 RTR
W
Reset: xxxxxxxx
Figure 10-28. Identifier Register 3 (IDR3) — Extended Identifier Mapping
Table 10-27. IDR3 Register Field Descriptions — Extended
Field Description
7:1
ID[6:0]
Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number.
0
RTR
Remote Transmission Request — This flag reflects the status of the remote transmission request bit in the
CAN frame. In the case of a receive buffer, it indicates the status of the received frame and supports the
transmission of an answering frame in software. In the case of a transmit buffer, this flag defines the setting of
the RTR bit to be sent.
0 Data frame
1 Remote frame
Module Base + 0x00X0
76543210
R
ID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3
W
Reset: xxxxxxxx
Figure 10-29. Identifier Register 0 — Standard Mapping
Table 10-28. IDR0 Register Field Descriptions — Standard
Field Description
7:0
ID[10:3]
Standard Format Identifier — The identifiers consist of 11 bits (ID[10:0]) for the standard format. ID10 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number. See also ID bits in Table 10-29.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 319
Rev 01.24
Module Base + 0x00X1
76543210
R
ID2 ID1 ID0 RTR IDE (=0)
W
Reset: xxxxxxxx
= Unused; always read ‘x’
Figure 10-30. Identifier Register 1 — Standard Mapping
Table 10-29. IDR1 Register Field Descriptions
Field Description
7:5
ID[2:0]
Standard Format Identifier — The identifiers consist of 11 bits (ID[10:0]) for the standard format. ID10 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number. See also ID bits in Table 10-28.
4
RTR
Remote Transmission Request — This flag reflects the status of the Remote Transmission Request bit in the
CAN frame. In the case of a receive buffer, it indicates the status of the received frame and supports the
transmission of an answering frame in software. In the case of a transmit buffer, this flag defines the setting of
the RTR bit to be sent.
0 Data frame
1 Remote frame
3
IDE
ID Extended — This flag indicates whether the extended or standard identifier format is applied in this buffer. In
the case of a receive buffer, the flag is set as received and indicates to the CPU how to process the buffer
identifier registers. In the case of a transmit buffer, the flag indicates to the MSCAN what type of identifier to send.
0 Standard format (11 bit)
1 Extended format (29 bit)
Module Base + 0x00X2
76543210
R
W
Reset: xxxxxxxx
= Unused; always read ‘x’
Figure 10-31. Identifier Register 2 — Standard Mapping
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
320 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.3.3.2 Data Segment Registers (DSR0-7)
The eight data segment registers, each with bits DB[7:0], contain the data to be transmitted or received.
The number of bytes to be transmitted or received is determined by the data length code in the
corresponding DLR register.
Module Base + 0x00X3
76543210
R
W
Reset: xxxxxxxx
= Unused; always read ‘x’
Figure 10-32. Identifier Register 3 — Standard Mapping
Module Base + 0x0004 (DSR0)
0x0005 (DSR1)
0x0006 (DSR2)
0x0007 (DSR3)
0x0008 (DSR4)
0x0009 (DSR5)
0x000A (DSR6)
0x000B (DSR7)
76543210
R
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
Reset: xxxxxxxx
Figure 10-33. Data Segment Registers (DSR0–DSR7) — Extended Identifier Mapping
Table 10-30. DSR0–DSR7 Register Field Descriptions
Field Description
7:0
DB[7:0]
Data bits 7:0
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 321
Rev 01.24
10.3.3.3 Data Length Register (DLR)
This register keeps the data length field of the CAN frame.
10.3.3.4 Transmit Buffer Priority Register (TBPR)
This register defines the local priority of the associated message buffer. The local priority is used for the
internal prioritization process of the MSCAN and is defined to be highest for the smallest binary number.
The MSCAN implements the following internal prioritization mechanisms:
• All transmission buffers with a cleared TXEx flag participate in the prioritization immediately
before the SOF (start of frame) is sent.
• The transmission buffer with the lowest local priority field wins the prioritization.
Module Base + 0x00XB
76543210
R
DLC3 DLC2 DLC1 DLC0
W
Reset: xxxxxxxx
= Unused; always read “x”
Figure 10-34. Data Length Register (DLR) — Extended Identifier Mapping
Table 10-31. DLR Register Field Descriptions
Field Description
3:0
DLC[3:0]
Data Length Code Bits — The data length code contains the number of bytes (data byte count) of the respective
message. During the transmission of a remote frame, the data length code is transmitted as programmed while
the number of transmitted data bytes is always 0. The data byte count ranges from 0 to 8 for a data frame.
Table 10-32 shows the effect of setting the DLC bits.
Table 10-32. Data Length Codes
Data Length Code Data Byte
Count
DLC3 DLC2 DLC1 DLC0
00000
00011
00102
00113
01004
01015
01106
01117
10008
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
322 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
In cases of more than one buffer having the same lowest priority, the message buffer with the lower index
number wins.
Read: Anytime when TXEx flag is set (see Section 10.3.2.7, “MSCAN Transmitter Flag Register
(CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 10.3.2.11,
“MSCAN Transmit Buffer Selection Register (CANTBSEL)”).
Write: Anytime when TXEx flag is set (see Section 10.3.2.7, “MSCAN Transmitter Flag Register
(CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 10.3.2.11,
“MSCAN Transmit Buffer Selection Register (CANTBSEL)”).
10.3.3.5 Time Stamp Register (TSRH–TSRL)
If the TIME bit is enabled, the MSCAN will write a time stamp to the respective registers in the active
transmit or receive buffer right after the EOF of a valid message on the CAN bus (see Section 10.3.2.1,
“MSCAN Control Register 0 (CANCTL0)”). In case of a transmission, the CPU can only read the time
stamp after the respective transmit buffer has been flagged empty.
The timer value, which is used for stamping, is taken from a free running internal CAN bit clock. A timer
overrun is not indicated by the MSCAN. The timer is reset (all bits set to 0) during initialization mode. The
CPU can only read the time stamp registers.
Module Base + 0xXXXD
76543210
R
PRIO7 PRIO6 PRIO5 PRIO4 PRIO3 PRIO2 PRIO1 PRIO0
W
Reset: 00000000
Figure 10-35. Transmit Buffer Priority Register (TBPR)
Module Base + 0xXXXE
76543210
R TSR15 TSR14 TSR13 TSR12 TSR11 TSR10 TSR9 TSR8
W
Reset: xxxxxxxx
Figure 10-36. Time Stamp Register — High Byte (TSRH)
Module Base + 0xXXXF
76543210
R TSR7 TSR6 TSR5 TSR4 TSR3 TSR2 TSR1 TSR0
W
Reset: xxxxxxxx
Figure 10-37. Time Stamp Register — Low Byte (TSRL)
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 323
Rev 01.24
Read: Anytime when TXEx flag is set (see Section 10.3.2.7, “MSCAN Transmitter Flag Register
(CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 10.3.2.11,
“MSCAN Transmit Buffer Selection Register (CANTBSEL)”).
Write: Unimplemented
10.4 Functional Description
10.4.1 General
This section provides a complete functional description of the MSCAN. It describes each of the features
and modes listed in the introduction.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
324 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.4.2 Message Storage
Figure 10-38. User Model for Message Buffer Organization
MSCAN facilitates a sophisticated message storage system which addresses the requirements of a broad
range of network applications.
MSCAN
Rx0
Rx1
CAN
Receive / Transmit
Engine
CPU12
Memory Mapped
I/O
CPU bus
MSCAN
Tx2
TXE2
PRIO
Receiver
Transmitter
RxBG
TxBG
Tx0
TXE0
PRIO
TxBG
Tx1
PRIO
TXE1
TxFG
CPU bus
Rx2
Rx3
Rx4
RXF
RxFG
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 325
Rev 01.24
10.4.2.1 Message Transmit Background
Modern application layer software is built upon two fundamental assumptions:
• Any CAN node is able to send out a stream of scheduled messages without releasing the CAN bus
between the two messages. Such nodes arbitrate for the CAN bus immediately after sending the
previous message and only release the CAN bus in case of lost arbitration.
• The internal message queue within any CAN node is organized such that the highest priority
message is sent out first, if more than one message is ready to be sent.
The behavior described in the bullets above cannot be achieved with a single transmit buffer. That buffer
must be reloaded immediately after the previous message is sent. This loading process lasts a finite amount
of time and must be completed within the inter-frame sequence (IFS) to be able to send an uninterrupted
stream of messages. Even if this is feasible for limited CAN bus speeds, it requires that the CPU reacts
with short latencies to the transmit interrupt.
A double buffer scheme de-couples the reloading of the transmit buffer from the actual message sending
and, therefore, reduces the reactiveness requirements of the CPU. Problems can arise if the sending of a
message is finished while the CPU re-loads the second buffer. No buffer would then be ready for
transmission, and the CAN bus would be released.
At least three transmit buffers are required to meet the first of the above requirements under all
circumstances. The MSCAN has three transmit buffers.
The second requirement calls for some sort of internal prioritization which the MSCAN implements with
the “local priority” concept described in Section 10.4.2.2, “Transmit Structures.”
10.4.2.2 Transmit Structures
The MSCAN triple transmit buffer scheme optimizes real-time performance by allowing multiple
messages to be set up in advance. The three buffers are arranged as shown in Figure 10-38.
All three buffers have a 13-byte data structure similar to the outline of the receive buffers (see
Section 10.3.3, “Programmer’s Model of Message Storage”). An additional Section 10.3.3.4, “Transmit
Buffer Priority Register (TBPR) contains an 8-bit local priority field (PRIO) (see Section 10.3.3.4,
“Transmit Buffer Priority Register (TBPR)”). The remaining two bytes are used for time stamping of a
message, if required (see Section 10.3.3.5, “Time Stamp Register (TSRH–TSRL)”).
To transmit a message, the CPU must identify an available transmit buffer, which is indicated by a set
transmitter buffer empty (TXEx) flag (see Section 10.3.2.7, “MSCAN Transmitter Flag Register
(CANTFLG)”). If a transmit buffer is available, the CPU must set a pointer to this buffer by writing to the
CANTBSEL register (see Section 10.3.2.11, “MSCAN Transmit Buffer Selection Register
(CANTBSEL)”). This makes the respective buffer accessible within the CANTXFG address space (see
Section 10.3.3, “Programmer’s Model of Message Storage”). The algorithmic feature associated with the
CANTBSEL register simplifies the transmit buffer selection. In addition, this scheme makes the handler
software simpler because only one address area is applicable for the transmit process, and the required
address space is minimized.
The CPU then stores the identifier, the control bits, and the data content into one of the transmit buffers.
Finally, the buffer is flagged as ready for transmission by clearing the associated TXE flag.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
326 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The MSCAN then schedules the message for transmission and signals the successful transmission of the
buffer by setting the associated TXE flag. A transmit interrupt (see Section 10.4.7.2, “Transmit Interrupt”)
is generated1 when TXEx is set and can be used to drive the application software to re-load the buffer.
If more than one buffer is scheduled for transmission when the CAN bus becomes available for arbitration,
the MSCAN uses the local priority setting of the three buffers to determine the prioritization. For this
purpose, every transmit buffer has an 8-bit local priority field (PRIO). The application software programs
this field when the message is set up. The local priority reflects the priority of this particular message
relative to the set of messages being transmitted from this node. The lowest binary value of the PRIO field
is defined to be the highest priority. The internal scheduling process takes place whenever the MSCAN
arbitrates for the CAN bus. This is also the case after the occurrence of a transmission error.
When a high priority message is scheduled by the application software, it may become necessary to abort
a lower priority message in one of the three transmit buffers. Because messages that are already in
transmission cannot be aborted, the user must request the abort by setting the corresponding abort request
bit (ABTRQ) (see Section 10.3.2.9, “MSCAN Transmitter Message Abort Request Register
(CANTARQ)”.) The MSCAN then grants the request, if possible, by:
1. Setting the corresponding abort acknowledge flag (ABTAK) in the CANTAAK register.
2. Setting the associated TXE flag to release the buffer.
3. Generating a transmit interrupt. The transmit interrupt handler software can determine from the
setting of the ABTAK flag whether the message was aborted (ABTAK = 1) or sent (ABTAK = 0).
10.4.2.3 Receive Structures
The received messages are stored in a five stage input FIFO. The five message buffers are alternately
mapped into a single memory area (see Figure 10-38). The background receive buffer (RxBG) is
exclusively associated with the MSCAN, but the foreground receive buffer (RxFG) is addressable by the
CPU (see Figure 10-38). This scheme simplifies the handler software because only one address area is
applicable for the receive process.
All receive buffers have a size of 15 bytes to store the CAN control bits, the identifier (standard or
extended), the data contents, and a time stamp, if enabled (see Section 10.3.3, “Programmer’s Model of
Message Storage”).
The receiver full flag (RXF) (see Section 10.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”)
signals the status of the foreground receive buffer. When the buffer contains a correctly received message
with a matching identifier, this flag is set.
On reception, each message is checked to see whether it passes the filter (see Section 10.4.3, “Identifier
Acceptance Filter”) and simultaneously is written into the active RxBG. After successful reception of a
valid message, the MSCAN shifts the content of RxBG into the receiver FIFO2, sets the RXF flag, and
generates a receive interrupt (see Section 10.4.7.3, “Receive Interrupt”) to the CPU3. The user’s receive
handler must read the received message from the RxFG and then reset the RXF flag to acknowledge the
interrupt and to release the foreground buffer. A new message, which can follow immediately after the IFS
field of the CAN frame, is received into the next available RxBG. If the MSCAN receives an invalid
1. The transmit interrupt occurs only if not masked. A polling scheme can be applied on TXEx also.
2. Only if the RXF flag is not set.
3. The receive interrupt occurs only if not masked. A polling scheme can be applied on RXF also.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 327
Rev 01.24
message in its RxBG (wrong identifier, transmission errors, etc.) the actual contents of the buffer will be
over-written by the next message. The buffer will then not be shifted into the FIFO.
When the MSCAN module is transmitting, the MSCAN receives its own transmitted messages into the
background receive buffer, RxBG, but does not shift it into the receiver FIFO, generate a receive interrupt,
or acknowledge its own messages on the CAN bus. The exception to this rule is in loopback mode (see
Section 10.3.2.2, “MSCAN Control Register 1 (CANCTL1)”) where the MSCAN treats its own messages
exactly like all other incoming messages. The MSCAN receives its own transmitted messages in the event
that it loses arbitration. If arbitration is lost, the MSCAN must be prepared to become a receiver.
An overrun condition occurs when all receive message buffers in the FIFO are filled with correctly
received messages with accepted identifiers and another message is correctly received from the CAN bus
with an accepted identifier. The latter message is discarded and an error interrupt with overrun indication
is generated if enabled (see Section 10.4.7.5, “Error Interrupt”). The MSCAN remains able to transmit
messages while the receiver FIFO being filled, but all incoming messages are discarded. As soon as a
receive buffer in the FIFO is available again, new valid messages will be accepted.
10.4.3 Identifier Acceptance Filter
The MSCAN identifier acceptance registers (see Section 10.3.2.12, “MSCAN Identifier Acceptance
Control Register (CANIDAC)”) define the acceptable patterns of the standard or extended identifier
(ID[10:0] or ID[28:0]). Any of these bits can be marked ‘don’t care’ in the MSCAN identifier mask
registers (see Section 10.3.2.17, “MSCAN Identifier Mask Registers (CANIDMR0–CANIDMR7)”).
A filter hit is indicated to the application software by a set receive buffer full flag (RXF = 1) and three bits
in the CANIDAC register (see Section 10.3.2.12, “MSCAN Identifier Acceptance Control Register
(CANIDAC)”). These identifier hit flags (IDHIT[2:0]) clearly identify the filter section that caused the
acceptance. They simplify the application software’s task to identify the cause of the receiver interrupt. If
more than one hit occurs (two or more filters match), the lower hit has priority.
A very flexible programmable generic identifier acceptance filter has been introduced to reduce the CPU
interrupt loading. The filter is programmable to operate in four different modes (see Bosch CAN 2.0A/B
protocol specification):
• Two identifier acceptance filters, each to be applied to:
— The full 29 bits of the extended identifier and to the following bits of the CAN 2.0B frame:
– Remote transmission request (RTR)
– Identifier extension (IDE)
– Substitute remote request (SRR)
— The 11 bits of the standard identifier plus the RTR and IDE bits of the CAN 2.0A/B messages1.
This mode implements two filters for a full length CAN 2.0B compliant extended identifier.
Figure 10-39 shows how the first 32-bit filter bank (CANIDAR0–CANIDAR3,
CANIDMR0–CANIDMR3) produces a filter 0 hit. Similarly, the second filter bank
(CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7) produces a filter 1 hit.
• Four identifier acceptance filters, each to be applied to
1. Although this mode can be used for standard identifiers, it is recommended to use the four or eight identifier acceptance
filters for standard identifiers
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
328 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
— a) the 14 most significant bits of the extended identifier plus the SRR and IDE bits of CAN 2.0B
messages or
— b) the 11 bits of the standard identifier, the RTR and IDE bits of CAN 2.0A/B messages.
Figure 10-40 shows how the first 32-bit filter bank (CANIDAR0–CANIDA3,
CANIDMR0–3CANIDMR) produces filter 0 and 1 hits. Similarly, the second filter bank
(CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7) produces filter 2 and 3 hits.
• Eight identifier acceptance filters, each to be applied to the first 8 bits of the identifier. This mode
implements eight independent filters for the first 8 bits of a CAN 2.0A/B compliant standard
identifier or a CAN 2.0B compliant extended identifier. Figure 10-41 shows how the first 32-bit
filter bank (CANIDAR0–CANIDAR3, CANIDMR0–CANIDMR3) produces filter 0 to 3 hits.
Similarly, the second filter bank (CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7)
produces filter 4 to 7 hits.
• Closed filter. No CAN message is copied into the foreground buffer RxFG, and the RXF flag is
never set.
Figure 10-39. 32-bit Maskable Identifier Acceptance Filter
ID28 ID21IDR0
ID10 ID3IDR0
ID20 ID15IDR1
ID2 IDEIDR1
ID14 ID7IDR2
ID10 ID3IDR2
ID6 RTRIDR3
ID10 ID3IDR3
AC7 AC0CANIDAR0
AM7 AM0CANIDMR0
AC7 AC0CANIDAR1
AM7 AM0CANIDMR1
AC7 AC0CANIDAR2
AM7 AM0CANIDMR2
AC7 AC0CANIDAR3
AM7 AM0CANIDMR3
ID Accepted (Filter 0 Hit)
CAN 2.0B
Extended Identifier
CAN 2.0A/B
Standard Identifier
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 329
Rev 01.24
Figure 10-40. 16-bit Maskable Identifier Acceptance Filters
ID28 ID21IDR0
ID10 ID3IDR0
ID20 ID15IDR1
ID2 IDEIDR1
ID14 ID7IDR2
ID10 ID3IDR2
ID6 RTRIDR3
ID10 ID3IDR3
AC7 AC0CANIDAR0
AM7 AM0CANIDMR0
AC7 AC0CANIDAR1
AM7 AM0CANIDMR1
ID Accepted (Filter 0 Hit)
AC7 AC0CANIDAR2
AM7 AM0CANIDMR2
AC7 AC0CANIDAR3
AM7 AM0CANIDMR3
ID Accepted (Filter 1 Hit)
CAN 2.0B
Extended Identifier
CAN 2.0A/B
Standard Identifier
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
330 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 10-41. 8-bit Maskable Identifier Acceptance Filters
CAN 2.0B
Extended Identifier
CAN 2.0A/B
Standard Identifier
AC7 AC0CIDAR3
AM7 AM0CIDMR3
ID Accepted (Filter 3 Hit)
AC7 AC0CIDAR2
AM7 AM0CIDMR2
ID Accepted (Filter 2 Hit)
AC7 AC0CIDAR1
AM7 AM0CIDMR1
ID Accepted (Filter 1 Hit)
ID28 ID21IDR0
ID10 ID3IDR0
ID20 ID15IDR1
ID2 IDEIDR1
ID14 ID7IDR2
ID10 ID3IDR2
ID6 RTRIDR3
ID10 ID3IDR3
AC7 AC0CIDAR0
AM7 AM0CIDMR0
ID Accepted (Filter 0 Hit)
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 331
Rev 01.24
10.4.3.1 Protocol Violation Protection
The MSCAN protects the user from accidentally violating the CAN protocol through programming errors.
The protection logic implements the following features:
• The receive and transmit error counters cannot be written or otherwise manipulated.
• All registers which control the configuration of the MSCAN cannot be modified while the MSCAN
is on-line. The MSCAN has to be in Initialization Mode. The corresponding INITRQ/INITAK
handshake bits in the CANCTL0/CANCTL1 registers (see Section 10.3.2.1, “MSCAN Control
Register 0 (CANCTL0)”) serve as a lock to protect the following registers:
— MSCAN control 1 register (CANCTL1)
— MSCAN bus timing registers 0 and 1 (CANBTR0, CANBTR1)
— MSCAN identifier acceptance control register (CANIDAC)
— MSCAN identifier acceptance registers (CANIDAR0–CANIDAR7)
— MSCAN identifier mask registers (CANIDMR0–CANIDMR7)
• The TXCAN pin is immediately forced to a recessive state when the MSCAN goes into the power
down mode or initialization mode (see Section 10.4.5.6, “MSCAN Power Down Mode,” and
Section 10.4.5.5, “MSCAN Initialization Mode”).
• The MSCAN enable bit (CANE) is writable only once in normal system operation modes, which
provides further protection against inadvertently disabling the MSCAN.
10.4.3.2 Clock System
Figure 10-42 shows the structure of the MSCAN clock generation circuitry.
Figure 10-42. MSCAN Clocking Scheme
The clock source bit (CLKSRC) in the CANCTL1 register (10.3.2.2/10-294) defines whether the internal
CANCLK is connected to the output of a crystal oscillator (oscillator clock) or to the bus clock.
The clock source has to be chosen such that the tight oscillator tolerance requirements (up to 0.4%) of the
CAN protocol are met. Additionally, for high CAN bus rates (1 Mbps), a 45% to 55% duty cycle of the
clock is required.
Bus Clock
Oscillator Clock
MSCAN
CANCLK
CLKSRC
CLKSRC
Prescaler
(1 .. 64)
Time quanta clock (Tq)
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
332 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
If the bus clock is generated from a PLL, it is recommended to select the oscillator clock rather than the
bus clock due to jitter considerations, especially at the faster CAN bus rates.
For microcontrollers without a clock and reset generator (CRG), CANCLK is driven from the crystal
oscillator (oscillator clock).
A programmable prescaler generates the time quanta (Tq) clock from CANCLK. A time quantum is the
atomic unit of time handled by the MSCAN.
Eqn. 10-2
A bit time is subdivided into three segments as described in the Bosch CAN specification. (see Figure 10-
43):
• SYNC_SEG: This segment has a fixed length of one time quantum. Signal edges are expected to
happen within this section.
• Time Segment 1: This segment includes the PROP_SEG and the PHASE_SEG1 of the CAN
standard. It can be programmed by setting the parameter TSEG1 to consist of 4 to 16 time quanta.
• Time Segment 2: This segment represents the PHASE_SEG2 of the CAN standard. It can be
programmed by setting the TSEG2 parameter to be 2 to 8 time quanta long.
Eqn. 10-3
Figure 10-43. Segments within the Bit Time
Tq
fCANCLK
Prescaler value(
)
----------------------------------------------------
--
=
Bit Rate fTq
number of Time Quanta()
---------------------------------------------------------------------------------=
SYNC_SEG Time Segment 1 Time Segment 2
1 4 ... 16 2 ... 8
8 ... 25 Time Quanta
= 1 Bit Time
NRZ Signal
Sample Point
(single or triple sampling)
(PROP_SEG + PHASE_SEG1) (PHASE_SEG2)
Transmit Point
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 333
Rev 01.24
The synchronization jump width (see the Bosch CAN specification for details) can be programmed in a
range of 1 to 4 time quanta by setting the SJW parameter.
The SYNC_SEG, TSEG1, TSEG2, and SJW parameters are set by programming the MSCAN bus timing
registers (CANBTR0, CANBTR1) (see Section 10.3.2.3, “MSCAN Bus Timing Register 0 (CANBTR0)”
and Section 10.3.2.4, “MSCAN Bus Timing Register 1 (CANBTR1)”).
Table 10-34 gives an overview of the CAN compliant segment settings and the related parameter values.
NOTE
It is the user’s responsibility to ensure the bit time settings are in compliance
with the CAN standard.
10.4.4 Modes of Operation
10.4.4.1 Normal Modes
The MSCAN module behaves as described within this specification in all normal system operation modes.
10.4.4.2 Special Modes
The MSCAN module behaves as described within this specification in all special system operation modes.
Table 10-33. Time Segment Syntax
Syntax Description
SYNC_SEG System expects transitions to occur on the CAN bus during this
period.
Transmit Point A node in transmit mode transfers a new value to the CAN bus at
this point.
Sample Point
A node in receive mode samples the CAN bus at this point. If the
three samples per bit option is selected, then this point marks the
position of the third sample.
Table 10-34. CAN Standard Compliant Bit Time Segment Settings
Time Segment 1 TSEG1 Time Segment 2 TSEG2 Synchronization
Jump Width SJW
5 .. 10 4 .. 9 2 1 1 .. 2 0 .. 1
4 .. 11 3 .. 10 3 2 1 .. 3 0 .. 2
5 .. 12 4 .. 11 4 3 1 .. 4 0 .. 3
6 .. 13 5 .. 12 5 4 1 .. 4 0 .. 3
7 .. 14 6 .. 13 6 5 1 .. 4 0 .. 3
8 .. 15 7 .. 14 7 6 1 .. 4 0 .. 3
9 .. 16 8 .. 15 8 7 1 .. 4 0 .. 3
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
334 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.4.4.3 Emulation Modes
In all emulation modes, the MSCAN module behaves just like normal system operation modes as
described within this specification.
10.4.4.4 Listen-Only Mode
In an optional CAN bus monitoring mode (listen-only), the CAN node is able to receive valid data frames
and valid remote frames, but it sends only “recessive” bits on the CAN bus. In addition, it cannot start a
transmision. If the MAC sub-layer is required to send a “dominant” bit (ACK bit, overload flag, or active
error flag), the bit is rerouted internally so that the MAC sub-layer monitors this “dominant” bit, although
the CAN bus may remain in recessive state externally.
10.4.4.5 Security Modes
The MSCAN module has no security features.
10.4.5 Low-Power Options
If the MSCAN is disabled (CANE = 0), the MSCAN clocks are stopped for power saving.
If the MSCAN is enabled (CANE = 1), the MSCAN has two additional modes with reduced power
consumption, compared to normal mode: sleep and power down mode. In sleep mode, power consumption
is reduced by stopping all clocks except those to access the registers from the CPU side. In power down
mode, all clocks are stopped and no power is consumed.
Table 10-35 summarizes the combinations of MSCAN and CPU modes. A particular combination of
modes is entered by the given settings on the CSWAI and SLPRQ/SLPAK bits.
For all modes, an MSCAN wake-up interrupt can occur only if the MSCAN is in sleep mode (SLPRQ = 1
and SLPAK = 1), wake-up functionality is enabled (WUPE = 1), and the wake-up interrupt is enabled
(WUPIE = 1).
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 335
Rev 01.24
10.4.5.1 Operation in Run Mode
As shown in Table 10-35, only MSCAN sleep mode is available as low power option when the CPU is in
run mode.
10.4.5.2 Operation in Wait Mode
The WAI instruction puts the MCU in a low power consumption stand-by mode. If the CSWAI bit is set,
additional power can be saved in power down mode because the CPU clocks are stopped. After leaving
this power down mode, the MSCAN restarts its internal controllers and enters normal mode again.
While the CPU is in wait mode, the MSCAN can be operated in normal mode and generate interrupts
(registers can be accessed via background debug mode). The MSCAN can also operate in any of the low-
power modes depending on the values of the SLPRQ/SLPAK and CSWAI bits as seen in Table 10-35.
10.4.5.3 Operation in Stop Mode
The STOP instruction puts the MCU in a low power consumption stand-by mode. In stop mode, the
MSCAN is set in power down mode regardless of the value of the SLPRQ/SLPAK and CSWAI bits
Table 10-35.
10.4.5.4 MSCAN Sleep Mode
The CPU can request the MSCAN to enter this low power mode by asserting the SLPRQ bit in the
CANCTL0 register. The time when the MSCAN enters sleep mode depends on a fixed synchronization
delay and its current activity:
Table 10-35. CPU vs. MSCAN Operating Modes
CPU Mode
MSCAN Mode
Normal
Reduced Power Consumption
Sleep Power Down Disabled
(CANE=0)
RUN
CSWAI = X(1)
SLPRQ = 0
SLPAK = 0
1. ‘X’ means don’t care.
CSWAI = X
SLPRQ = 1
SLPAK = 1
CSWAI = X
SLPRQ = X
SLPAK = X
WAIT
CSWAI = 0
SLPRQ = 0
SLPAK = 0
CSWAI = 0
SLPRQ = 1
SLPAK = 1
CSWAI = 1
SLPRQ = X
SLPAK = X
CSWAI = X
SLPRQ = X
SLPAK = X
STOP
CSWAI = X
SLPRQ = X
SLPAK = X
CSWAI = X
SLPRQ = X
SLPAK = X
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
336 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
• If there are one or more message buffers scheduled for transmission (TXEx = 0), the MSCAN will
continue to transmit until all transmit message buffers are empty (TXEx = 1, transmitted
successfully or aborted) and then goes into sleep mode.
• If the MSCAN is receiving, it continues to receive and goes into sleep mode as soon as the CAN
bus next becomes idle.
• If the MSCAN is neither transmitting nor receiving, it immediately goes into sleep mode.
Figure 10-44. Sleep Request / Acknowledge Cycle
NOTE
The application software must avoid setting up a transmission (by clearing
one or more TXEx flag(s)) and immediately request sleep mode (by setting
SLPRQ). Whether the MSCAN starts transmitting or goes into sleep mode
directly depends on the exact sequence of operations.
If sleep mode is active, the SLPRQ and SLPAK bits are set (Figure 10-44). The application software must
use SLPAK as a handshake indication for the request (SLPRQ) to go into sleep mode.
When in sleep mode (SLPRQ = 1 and SLPAK = 1), the MSCAN stops its internal clocks. However, clocks
that allow register accesses from the CPU side continue to run.
If the MSCAN is in bus-off state, it stops counting the 128 occurrences of 11 consecutive recessive bits
due to the stopped clocks. The TXCAN pin remains in a recessive state. If RXF = 1, the message can be
read and RXF can be cleared. Shifting a new message into the foreground buffer of the receiver FIFO
(RxFG) does not take place while in sleep mode.
It is possible to access the transmit buffers and to clear the associated TXE flags. No message abort takes
place while in sleep mode.
If the WUPE bit in CANCLT0 is not asserted, the MSCAN will mask any activity it detects on CAN. The
RXCAN pin is therefore held internally in a recessive state. This locks the MSCAN in sleep mode
(Figure 10-45). WUPE must be set before entering sleep mode to take effect.
SYNC
SYNC
Bus Clock Domain CAN Clock Domain
MSCAN
in Sleep Mode
CPU
Sleep Request
SLPRQ
Flag
SLPAK
Flag
SLPRQ
sync.
SLPAK
sync.
SLPRQ
SLPAK
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 337
Rev 01.24
The MSCAN is able to leave sleep mode (wake up) only when:
• CAN bus activity occurs and WUPE = 1
or
• the CPU clears the SLPRQ bit
NOTE
The CPU cannot clear the SLPRQ bit before sleep mode (SLPRQ = 1 and
SLPAK = 1) is active.
After wake-up, the MSCAN waits for 11 consecutive recessive bits to synchronize to the CAN bus. As a
consequence, if the MSCAN is woken-up by a CAN frame, this frame is not received.
The receive message buffers (RxFG and RxBG) contain messages if they were received before sleep mode
was entered. All pending actions will be executed upon wake-up; copying of RxBG into RxFG, message
aborts and message transmissions. If the MSCAN remains in bus-off state after sleep mode was exited, it
continues counting the 128 occurrences of 11 consecutive recessive bits.
Figure 10-45. Simplified State Transitions for Entering/Leaving Sleep Mode
Wait
Idle
Tx/Rx
Message
Active
CAN Activity
CAN Activity &
Sleep
SLPRQ
StartUp for Idle
(CAN Activity & WUPE) |
(CAN Activity & WUPE) | SLPRQ
CAN Activity
CAN Activity
CAN Activity &
CAN Activity
SLPRQ
SLPRQ
CAN Activity
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
338 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.4.5.5 MSCAN Initialization Mode
In initialization mode, any on-going transmission or reception is immediately aborted and synchronization
to the CAN bus is lost, potentially causing CAN protocol violations. To protect the CAN bus system from
fatal consequences of violations, the MSCAN immediately drives the TXCAN pin into a recessive state.
NOTE
The user is responsible for ensuring that the MSCAN is not active when
initialization mode is entered. The recommended procedure is to bring the
MSCAN into sleep mode (SLPRQ = 1 and SLPAK = 1) before setting the
INITRQ bit in the CANCTL0 register. Otherwise, the abort of an on-going
message can cause an error condition and can impact other CAN bus
devices.
In initialization mode, the MSCAN is stopped. However, interface registers remain accessible. This mode
is used to reset the CANCTL0, CANRFLG, CANRIER, CANTFLG, CANTIER, CANTARQ,
CANTAAK, and CANTBSEL registers to their default values. In addition, the MSCAN enables the
configuration of the CANBTR0, CANBTR1 bit timing registers; CANIDAC; and the CANIDAR,
CANIDMR message filters. See Section 10.3.2.1, “MSCAN Control Register 0 (CANCTL0),” for a
detailed description of the initialization mode.
Figure 10-46. Initialization Request/Acknowledge Cycle
Due to independent clock domains within the MSCAN, INITRQ must be synchronized to all domains by
using a special handshake mechanism. This handshake causes additional synchronization delay (see
Section Figure 10-46., “Initialization Request/Acknowledge Cycle”).
If there is no message transfer ongoing on the CAN bus, the minimum delay will be two additional bus
clocks and three additional CAN clocks. When all parts of the MSCAN are in initialization mode, the
INITAK flag is set. The application software must use INITAK as a handshake indication for the request
(INITRQ) to go into initialization mode.
NOTE
The CPU cannot clear INITRQ before initialization mode (INITRQ = 1 and
INITAK = 1) is active.
SYNC
SYNC
Bus Clock Domain CAN Clock Domain
CPU
Init Request
INIT
Flag
INITAK
Flag
INITRQ
sync.
INITAK
sync.
INITRQ
INITAK
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 339
Rev 01.24
10.4.5.6 MSCAN Power Down Mode
The MSCAN is in power down mode (Table 10-35) when
• CPU is in stop mode
or
• CPU is in wait mode and the CSWAI bit is set
When entering the power down mode, the MSCAN immediately stops all ongoing transmissions and
receptions, potentially causing CAN protocol violations. To protect the CAN bus system from fatal
consequences of violations to the above rule, the MSCAN immediately drives the TXCAN pin into a
recessive state.
NOTE
The user is responsible for ensuring that the MSCAN is not active when
power down mode is entered. The recommended procedure is to bring the
MSCAN into Sleep mode before the STOP or WAI instruction (if CSWAI
is set) is executed. Otherwise, the abort of an ongoing message can cause an
error condition and impact other CAN bus devices.
In power down mode, all clocks are stopped and no registers can be accessed. If the MSCAN was not in
sleep mode before power down mode became active, the module performs an internal recovery cycle after
powering up. This causes some fixed delay before the module enters normal mode again.
10.4.5.7 Programmable Wake-Up Function
The MSCAN can be programmed to wake up the MSCAN as soon as CAN bus activity is detected (see
control bit WUPE in Section 10.3.2.1, “MSCAN Control Register 0 (CANCTL0)”). The sensitivity to
existing CAN bus action can be modified by applying a low-pass filter function to the RXCAN input line
while in sleep mode (see control bit WUPM in Section 10.3.2.2, “MSCAN Control Register 1
(CANCTL1)”).
This feature can be used to protect the MSCAN from wake-up due to short glitches on the CAN bus lines.
Such glitches can result from—for example—electromagnetic interference within noisy environments.
10.4.6 Reset Initialization
The reset state of each individual bit is listed in Section 10.3.2, “Register Descriptions,” which details all
the registers and their bit-fields.
10.4.7 Interrupts
This section describes all interrupts originated by the MSCAN. It documents the enable bits and generated
flags. Each interrupt is listed and described separately.
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
340 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
10.4.7.1 Description of Interrupt Operation
The MSCAN supports four interrupt vectors (see Table 10-36), any of which can be individually masked
(for details see sections from Section 10.3.2.6, “MSCAN Receiver Interrupt Enable Register
(CANRIER),” to Section 10.3.2.8, “MSCAN Transmitter Interrupt Enable Register (CANTIER)”).
NOTE
The dedicated interrupt vector addresses are defined in the Resets and
Interrupts chapter.
10.4.7.2 Transmit Interrupt
At least one of the three transmit buffers is empty (not scheduled) and can be loaded to schedule a message
for transmission. The TXEx flag of the empty message buffer is set.
10.4.7.3 Receive Interrupt
A message is successfully received and shifted into the foreground buffer (RxFG) of the receiver FIFO.
This interrupt is generated immediately after receiving the EOF symbol. The RXF flag is set. If there are
multiple messages in the receiver FIFO, the RXF flag is set as soon as the next message is shifted to the
foreground buffer.
10.4.7.4 Wake-Up Interrupt
A wake-up interrupt is generated if activity on the CAN bus occurs during MSCN internal sleep mode.
WUPE (see Section 10.3.2.1, “MSCAN Control Register 0 (CANCTL0)”) must be enabled.
10.4.7.5 Error Interrupt
An error interrupt is generated if an overrun of the receiver FIFO, error, warning, or bus-off condition
occurrs. Section 10.3.2.5, “MSCAN Receiver Flag Register (CANRFLG) indicates one of the following
conditions:
•Overrun — An overrun condition of the receiver FIFO as described in Section 10.4.2.3, “Receive
Structures,” occurred.
•CAN Status Change — The actual value of the transmit and receive error counters control the
CAN bus state of the MSCAN. As soon as the error counters skip into a critical range (Tx/Rx-
warning, Tx/Rx-error, bus-off) the MSCAN flags an error condition. The status change, which
caused the error condition, is indicated by the TSTAT and RSTAT flags (see Section 10.3.2.5,
Table 10-36. Interrupt Vectors
Interrupt Source CCR Mask Local Enable
Wake-Up Interrupt (WUPIF) I bit CANRIER (WUPIE)
Error Interrupts Interrupt (CSCIF, OVRIF) I bit CANRIER (CSCIE, OVRIE)
Receive Interrupt (RXF) I bit CANRIER (RXFIE)
Transmit Interrupts (TXE[2:0]) I bit CANTIER (TXEIE[2:0])
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 341
Rev 01.24
“MSCAN Receiver Flag Register (CANRFLG)” and Section 10.3.2.6, “MSCAN Receiver
Interrupt Enable Register (CANRIER)”).
10.4.7.6 Interrupt Acknowledge
Interrupts are directly associated with one or more status flags in either the Section 10.3.2.5, “MSCAN
Receiver Flag Register (CANRFLG)” or the Section 10.3.2.7, “MSCAN Transmitter Flag Register
(CANTFLG).” Interrupts are pending as long as one of the corresponding flags is set. The flags in
CANRFLG and CANTFLG must be reset within the interrupt handler to handshake the interrupt. The flags
are reset by writing a 1 to the corresponding bit position. A flag cannot be cleared if the respective
condition prevails.
NOTE
It must be guaranteed that the CPU clears only the bit causing the current
interrupt. For this reason, bit manipulation instructions (BSET) must not be
used to clear interrupt flags. These instructions may cause accidental
clearing of interrupt flags which are set after entering the current interrupt
service routine.
10.4.7.7 Recovery from Stop or Wait
The MSCAN can recover from stop or wait via the wake-up interrupt. This interrupt can only occur if the
MSCAN was in sleep mode (SLPRQ = 1 and SLPAK = 1) before entering power down mode, the wake-
up option is enabled (WUPE = 1), and the wake-up interrupt is enabled (WUPIE = 1).
10.5 Initialization/Application Information
10.5.1 MSCAN initialization
The procedure to initially start up the MSCAN module out of reset is as follows:
1. Assert CANE
2. Write to the configuration registers in initialization mode
3. Clear INITRQ to leave initialization mode and enter normal mode
If the configuration of registers which are writable in initialization mode needs to be changed only when
the MSCAN module is in normal mode:
1. Bring the module into sleep mode by setting SLPRQ and awaiting SLPAK to assert after the CAN
bus becomes idle.
2. Enter initialization mode: assert INITRQ and await INITAK
3. Write to the configuration registers in initialization mode
4. Clear INITRQ to leave initialization mode and continue in normal mode
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
342 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 343
Rev 01.24
Chapter 11
Oscillator (OSCV2) Block Description
11.1 Introduction
The OSCV2 module provides two alternative oscillator concepts:
• A low noise and low power Colpitts oscillator with amplitude limitation control (ALC)
• A robust full swing Pierce oscillator with the possibility to feed in an external square wave
11.1.1 Features
The Colpitts OSCV2 option provides the following features:
• Amplitude limitation control (ALC) loop:
— Low power consumption and low current induced RF emission
— Sinusoidal waveform with low RF emission
— Low crystal stress (an external damping resistor is not required)
— Normal and low amplitude mode for further reduction of power and emission
• An external biasing resistor is not required
The Pierce OSC option provides the following features:
• Wider high frequency operation range
• No DC voltage applied across the crystal
• Full rail-to-rail (2.5 V nominal) swing oscillation with low EM susceptibility
• Fast start up
Common features:
• Clock monitor (CM)
• Operation from the VDDPLL 2.5 V (nominal) supply rail
11.1.2 Modes of Operation
Two modes of operation exist:
• Amplitude limitation controlled Colpitts oscillator mode suitable for power and emission critical
applications
• Full swing Pierce oscillator mode that can also be used to feed in an externally generated square
wave suitable for high frequency operation and harsh environments
Chapter 11 Oscillator (OSCV2) Block Description
344 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
11.2 External Signal Description
This section lists and describes the signals that connect off chip.
11.2.1 VDDPLL and VSSPLL — PLL Operating Voltage, PLL Ground
These pins provide the operating voltage (VDDPLL) and ground (VSSPLL) for the OSCV2 circuitry. This
allows the supply voltage to the OSCV2 to be independently bypassed.
11.2.2 EXTAL and XTAL — Clock/Crystal Source Pins
These pins provide the interface for either a crystal or a CMOS compatible clock to control the internal
clock generator circuitry. EXTAL is the external clock input or the input to the crystal oscillator amplifier.
XTAL is the output of the crystal oscillator amplifier. All the MCU internal system clocks are derived from
the EXTAL input frequency. In full stop mode (PSTP = 0) the EXTAL pin is pulled down by an internal
resistor of typical 200 kΩ.
NOTE
Freescale Semiconductor recommends an evaluation of the application
board and chosen resonator or crystal by the resonator or crystal supplier.
The Crystal circuit is changed from standard.
The Colpitts circuit is not suited for overtone resonators and crystals.
Figure 11-1. Colpitts Oscillator Connections (XCLKS = 0)
NOTE
The Pierce circuit is not suited for overtone resonators and crystals without
a careful component selection.
MCU
C2
EXTAL
XTAL
VSSPLL
C1
CDC* Crystal or Ceramic
Resonator
* Due to the nature of a translated ground Colpitts oscillator
a DC voltage bias is applied to the crystal.
Please contact the crystal manufacturer for crystal DC bias
conditions and recommended capacitor value CDC.
Chapter 11 Oscillator (OSCV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 345
Rev 01.24
Figure 11-2. Pierce Oscillator Connections (XCLKS = 1)
Figure 11-3. External Clock Connections (XCLKS = 1)
11.2.3 XCLKS — Colpitts/Pierce Oscillator Selection Signal
The XCLKS is an input signal which controls whether a crystal in combination with the internal Colpitts
(low power) oscillator is used or whether the Pierce oscillator/external clock circuitry is used. The XCLKS
signal is sampled during reset with the rising edge of RESET. Table 11-1 lists the state coding of the
sampled XCLKS signal. Refer to the device overview chapter for polarity of the XCLKS pin.
Table 11-1. Clock Selection Based on XCLKS
XCLKS Description
0 Colpitts oscillator selected
1 Pierce oscillator/external clock selected
MCU
EXTAL
XTAL RS*
RB
VSSPLL
Crystal or Ceramic
Resonator
C4
C3
* Rs can be zero (shorted) when used with higher frequency crystals.
Refer to manufacturer’s data.
MCU
EXTAL
XTAL
CMOS-Compatible
External Oscillator
Not Connected
(VDDPLL Level)
Chapter 11 Oscillator (OSCV2) Block Description
346 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
11.3 Memory Map and Register Definition
The CRG contains the registers and associated bits for controlling and monitoring the OSCV2 module.
11.4 Functional Description
The OSCV2 block has two external pins, EXTAL and XTAL. The oscillator input pin, EXTAL, is intended
to be connected to either a crystal or an external clock source. The selection of Colpitts oscillator or Pierce
oscillator/external clock depends on the XCLKS signal which is sampled during reset. The XTAL pin is
an output signal that provides crystal circuit feedback.
A buffered EXTAL signal, OSCCLK, becomes the internal reference clock. To improve noise immunity,
the oscillator is powered by the VDDPLL and VSSPLL power supply pins.
The Pierce oscillator can be used for higher frequencies compared to the low power Colpitts oscillator.
11.4.1 Amplitude Limitation Control (ALC)
The Colpitts oscillator is equipped with a feedback system which does not waste current by generating
harmonics. Its configuration is “Colpitts oscillator with translated ground.” The transconductor used is
driven by a current source under the control of a peak detector which will measure the amplitude of the
AC signal appearing on EXTAL node in order to implement an amplitude limitation control (ALC) loop.
The ALC loop is in charge of reducing the quiescent current in the transconductor as a result of an increase
in the oscillation amplitude. The oscillation amplitude can be limited to two values. The normal amplitude
which is intended for non power saving modes and a small amplitude which is intended for low power
operation modes. Please refer to the CRG block description chapter for the control and assignment of the
amplitude value to operation modes.
11.4.2 Clock Monitor (CM)
The clock monitor circuit is based on an internal resistor-capacitor (RC) time delay so that it can operate
without any MCU clocks. If no OSCCLK edges are detected within this RC time delay, the clock monitor
indicates a failure which asserts self clock mode or generates a system reset depending on the state of
SCME bit. If the clock monitor is disabled or the presence of clocks is detected no failure is indicated.The
clock monitor function is enabled/disabled by the CME control bit, described in the CRG block description
chapter.
11.5 Interrupts
OSCV2 contains a clock monitor, which can trigger an interrupt or reset. The control bits and status bits
for the clock monitor are described in the CRG block description chapter.
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 347
Rev 01.24
Chapter 12
Pulse-Width Modulator (PWM8B6CV1) Block Description
12.1 Introduction
The pulse width modulation (PWM) definition is based on the HC12 PWM definitions. The PWM8B6CV1
module contains the basic features from the HC11 with some of the enhancements incorporated on the
HC12, that is center aligned output mode and four available clock sources. The PWM8B6CV1 module has
six channels with independent control of left and center aligned outputs on each channel.
Each of the six PWM channels has a programmable period and duty cycle as well as a dedicated counter.
A flexible clock select scheme allows a total of four different clock sources to be used with the counters.
Each of the modulators can create independent continuous waveforms with software-selectable duty rates
from 0% to 100%. The PWM outputs can be programmed as left aligned outputs or center aligned outputs
12.1.1 Features
• Six independent PWM channels with programmable period and duty cycle
• Dedicated counter for each PWM channel
• Programmable PWM enable/disable for each channel
• Software selection of PWM duty pulse polarity for each channel
• Period and duty cycle are double buffered. Change takes effect when the end of the effective period
is reached (PWM counter reaches 0) or when the channel is disabled.
• Programmable center or left aligned outputs on individual channels
• Six 8-bit channel or three 16-bit channel PWM resolution
• Four clock sources (A, B, SA, and SB) provide for a wide range of frequencies.
• Programmable clock select logic
• Emergency shutdown
12.1.2 Modes of Operation
There is a software programmable option for low power consumption in wait mode that disables the input
clock to the prescaler.
In freeze mode there is a software programmable option to disable the input clock to the prescaler. This is
useful for emulation.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
348 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
12.1.3 Block Diagram
Figure 12-1. PWM8B6CV1 Block Diagram
12.2 External Signal Description
The PWM8B6CV1 module has a total of six external pins.
12.2.1 PWM5 — Pulse Width Modulator Channel 5 Pin
This pin serves as waveform output of PWM channel 5 and as an input for the emergency shutdown
feature.
12.2.2 PWM4 — Pulse Width Modulator Channel 4 Pin
This pin serves as waveform output of PWM channel 4.
12.2.3 PWM3 — Pulse Width Modulator Channel 3 Pin
This pin serves as waveform output of PWM channel 3.
Period and Duty Counter
Channel 5
Bus Clock Clock Select PWM Clock
Period and Duty Counter
Channel 4
Period and Duty Counter
Channel 3
Period and Duty Counter
Channel 2
Period and Duty Counter
Channel 1
Period and Duty Counter
Channel 0
PWM Channels
Alignment
Polarity
Control
PWM8B6C
PWM5
PWM4
PWM3
PWM2
PWM1
PWM0
Enable
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 349
Rev 01.24
12.2.4 PWM2 — Pulse Width Modulator Channel 2 Pin
This pin serves as waveform output of PWM channel 2.
12.2.5 PWM1 — Pulse Width Modulator Channel 1 Pin
This pin serves as waveform output of PWM channel 1.
12.2.6 PWM0 — Pulse Width Modulator Channel 0 Pin
This pin serves as waveform output of PWM channel 0.
12.3 Memory Map and Register Definition
This subsection describes in detail all the registers and register bits in the PWM8B6CV1 module.
The special-purpose registers and register bit functions that would not normally be made available to
device end users, such as factory test control registers and reserved registers are clearly identified by means
of shading the appropriate portions of address maps and register diagrams. Notes explaining the reasons
for restricting access to the registers and functions are also explained in the individual register descriptions.
12.3.1 Module Memory Map
The following paragraphs describe the content of the registers in the PWM8B6CV1 module. The base
address of the PWM8B6CV1 module is determined at the MCU level when the MCU is defined. The
register decode map is fixed and begins at the first address of the module address offset. Table 12-1 shows
the registers associated with the PWM and their relative offset from the base address. The register detail
description follows the order in which they appear in the register map.
Reserved bits within a register will always read as 0 and the write will be unimplemented. Unimplemented
functions are indicated by shading the bit.
Table 12-1 shows the memory map for the PWM8B6CV1 module.
NOTE
Register address = base address + address offset, where the base address is
defined at the MCU level and the address offset is defined at the module
level.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
350 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 12-1. PWM8B6CV1 Memory Map
Address
Offset Register Access
0x0000 PWM Enable Register (PWME) R/W
0x0001 PWM Polarity Register (PWMPOL) R/W
0x0002 PWM Clock Select Register (PWMCLK) R/W
0x0003 PWM Prescale Clock Select Register (PWMPRCLK) R/W
0x0004 PWM Center Align Enable Register (PWMCAE) R/W
0x0005 PWM Control Register (PWMCTL) R/W
0x0006 PWM Test Register (PWMTST)(1)
1. PWMTST is intended for factory test purposes only.
R/W
0x0007 PWM Prescale Counter Register (PWMPRSC)(2)
2. PWMPRSC is intended for factory test purposes only.
R/W
0x0008 PWM Scale A Register (PWMSCLA) R/W
0x0009 PWM Scale B Register (PWMSCLB) R/W
0x000A PWM Scale A Counter Register (PWMSCNTA)(3)
3. PWMSCNTA is intended for factory test purposes only.
R/W
0x000B PWM Scale B Counter Register (PWMSCNTB)(4)
4. PWMSCNTB is intended for factory test purposes only.
R/W
0x000C PWM Channel 0 Counter Register (PWMCNT0) R/W
0x000D PWM Channel 1 Counter Register (PWMCNT1) R/W
0x000E PWM Channel 2 Counter Register (PWMCNT2) R/W
0x000F PWM Channel 3 Counter Register (PWMCNT3) R/W
0x0010 PWM Channel 4 Counter Register (PWMCNT4) R/W
0x0011 PWM Channel 5 Counter Register (PWMCNT5) R/W
0x0012 PWM Channel 0 Period Register (PWMPER0) R/W
0x0013 PWM Channel 1 Period Register (PWMPER1) R/W
0x0014 PWM Channel 2 Period Register (PWMPER2) R/W
0x0015 PWM Channel 3 Period Register (PWMPER3) R/W
0x0016 PWM Channel 4 Period Register (PWMPER4) R/W
0x0017 PWM Channel 5 Period Register (PWMPER5) R/W
0x0018 PWM Channel 0 Duty Register (PWMDTY0) R/W
0x0019 PWM Channel 1 Duty Register (PWMDTY1) R/W
0x001A PWM Channel 2 Duty Register (PWMDTY2) R/W
0x001B PWM Channel 3 Duty Register (PWMDTY3) R/W
0x001C PWM Channel 4 Duty Register (PWMDTY4) R/W
0x001D PWM Channel 5 Duty Register (PWMDTY5) R/W
0x001E PWM Shutdown Register (PWMSDN) R/W
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 351
Rev 01.24
12.3.2 Register Descriptions
The following paragraphs describe in detail all the registers and register bits in the PWM8B6CV1 module.
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000
PWME
R0 0 PWME5 PWME4 PWME3 PWME2 PWME1 PWME0
W
0x0001
PWMPOL
R0 0 PPOL5 PPOL4 PPOL3 PPOL2 PPOL1 PPOL0
W
0x0002
PWMCLK
R0 0 PCLK5 PCLK4 PCLK3 PCLK2 PCLK1 PCLK0
W
0x0003
PWMPRCLK
R0 PCKB2 PCKB1 PCKB0 0PCKA2 PCKA1 PCKA0
W
0x0004
PWMCAE
R0 0 CAE5 CAE4 CAE2 CAE2 CAE1 CAE0
W
0x0005
PWMCTL
R0 CON45 CON23 CON01 PSWAI PFRZ 00
W
0x0006
PWMTST
R00000000
W
0x0007
PWMPRSC
R00000000
W
0x0008
PWMSCLA
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0009
PWMSCLB
RBit 7 6 5 4 3 2 1 Bit 0
W
0x000A
PWMSCNTA
R00000000
W
0x000B
PWMSCNTB
R00000000
W
0x000C
PWMCNT0
R Bit 7 6 5 4 3 2 1 Bit 0
W00000000
0x000D
PWMCNT1
R Bit 7 6 5 4 3 2 1 Bit 0
W00000000
0x000E
PWMCNT2
R Bit 7 6 5 4 3 2 1 Bit 0
W00000000
= Unimplemented or Reserved
Figure 12-2. PWM Register Summary
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
352 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
0x000F
PWMCNT3
R Bit 7 6 5 4 3 2 1 Bit 0
W00000000
0x0010
PWMCNT4
R Bit 7 6 5 4 3 2 1 Bit 0
W00000000
0x0011
PWMCNT5
R Bit 7 6 5 4 3 2 1 Bit 0
W00000000
0x0012
PWMPER0
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0013
PWMPER1
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0014
PWMPER2
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0015
PWMPER3
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0016
PWMPER4
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0017
PWMPER5
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0018
PWMDTY0
RBit 7 6 5 4 3 2 1 Bit 0
W
0x0019
PWMPER1
RBit 7 6 5 4 3 2 1 Bit 0
W
0x001A
PWMPER2
RBit 7 6 5 4 3 2 1 Bit 0
W
0x001B
PWMPER3
RBit 7 6 5 4 3 2 1 Bit 0
W
0x001C
PWMPER4
RBit 7 6 5 4 3 2 1 Bit 0
W
0x001D
PWMPER5
RBit 7 6 5 4 3 2 1 Bit 0
W
0x001E
PWMSDB
RPWMIF PWMIE 0PWMLVL 0 PWM5IN PWM5INL PWM5ENA
W PWMRSTRT
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
= Unimplemented or Reserved
Figure 12-2. PWM Register Summary (continued)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 353
Rev 01.24
12.3.2.1 PWM Enable Register (PWME)
Each PWM channel has an enable bit (PWMEx) to start its waveform output. When any of the PWMEx
bits are set (PWMEx = 1), the associated PWM output is enabled immediately. However, the actual PWM
waveform is not available on the associated PWM output until its clock source begins its next cycle due to
the synchronization of PWMEx and the clock source.
NOTE
The first PWM cycle after enabling the channel can be irregular.
An exception to this is when channels are concatenated. After concatenated mode is enabled (CONxx bits
set in PWMCTL register), enabling/disabling the corresponding 16-bit PWM channel is controlled by the
low-order PWMEx bit. In this case, the high-order bytes PWMEx bits have no effect and their
corresponding PWM output lines are disabled.
While in run mode, if all six PWM channels are disabled (PWME5–PWME0 = 0), the prescaler counter
shuts off for power savings.
Read: anytime
Write: anytime
Module Base + 0x0000
76543210
R0 0 PWME5 PWME4 PWME3 PWME2 PWME1 PWME0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-3. PWM Enable Register (PWME)
Table 12-2. PWME Field Descriptions
Field Description
5
PWME5
Pulse Width Channel 5 Enable
0 Pulse width channel 5 is disabled.
1 Pulse width channel 5 is enabled. The pulse modulated signal becomes available at PWM,output bit 5 when
its clock source begins its next cycle.
4
PWME4
Pulse Width Channel 4 Enable
0 Pulse width channel 4 is disabled.
1 Pulse width channel 4 is enabled. The pulse modulated signal becomes available at PWM, output bit 4 when
its clock source begins its next cycle. If CON45 = 1, then bit has no effect and PWM output line 4 is disabled.
3
PWME3
Pulse Width Channel 3 Enable
0 Pulse width channel 3 is disabled.
1 Pulse width channel 3 is enabled. The pulse modulated signal becomes available at PWM, output bit 3 when
its clock source begins its next cycle.
2
PWME2
Pulse Width Channel 2 Enable
0 Pulse width channel 2 is disabled.
1 Pulse width channel 2 is enabled. The pulse modulated signal becomes available at PWM, output bit 2 when
its clock source begins its next cycle. If CON23 = 1, then bit has no effect and PWM output line 2 is disabled.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
354 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
12.3.2.2 PWM Polarity Register (PWMPOL)
The starting polarity of each PWM channel waveform is determined by the associated PPOLx bit in the
PWMPOL register. If the polarity bit is 1, the PWM channel output is high at the beginning of the cycle
and then goes low when the duty count is reached. Conversely, if the polarity bit is 0 the output starts low
and then goes high when the duty count is reached.
Read: anytime
Write: anytime
NOTE
PPOLx register bits can be written anytime. If the polarity is changed while
a PWM signal is being generated, a truncated or stretched pulse can occur
during the transition
1
PWME1
Pulse Width Channel 1 Enable
0 Pulse width channel 1 is disabled.
1 Pulse width channel 1 is enabled. The pulse modulated signal becomes available at PWM, output bit 1 when
its clock source begins its next cycle.
0
PWME0
Pulse Width Channel 0 Enable
0 Pulse width channel 0 is disabled.
1 Pulse width channel 0 is enabled. The pulse modulated signal becomes available at PWM, output bit 0 when
its clock source begins its next cycle. If CON01 = 1, then bit has no effect and PWM output line 0 is disabled.
Module Base + 0x0001
76543210
R0 0 PPOL5 PPOL4 PPOL3 PPOL2 PPOL1 PPOL0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-4. PWM Polarity Register (PWMPOL)
Table 12-3. PWMPOL Field Descriptions
Field Description
5
PPOL5
Pulse Width Channel 5 Polarity
0 PWM channel 5 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 5 output is high at the beginning of the period, then goes low when the duty count is reached.
4
PPOL4
Pulse Width Channel 4 Polarity
0 PWM channel 4 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 4 output is high at the beginning of the period, then goes low when the duty count is reached.
Table 12-2. PWME Field Descriptions (continued)
Field Description
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 355
Rev 01.24
12.3.2.3 PWM Clock Select Register (PWMCLK)
Each PWM channel has a choice of two clocks to use as the clock source for that channel as described
below.
Read: anytime
Write: anytime
NOTE
Register bits PCLK0 to PCLK5 can be written anytime. If a clock select is
changed while a PWM signal is being generated, a truncated or stretched
pulse can occur during the transition.
3
PPOL3
Pulse Width Channel 3 Polarity
0 PWM channel 3 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 3 output is high at the beginning of the period, then goes low when the duty count is reached.
2
PPOL2
Pulse Width Channel 2 Polarity
0 PWM channel 2 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 2 output is high at the beginning of the period, then goes low when the duty count is reached.
1
PPOL1
Pulse Width Channel 1 Polarity
0 PWM channel 1 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 1 output is high at the beginning of the period, then goes low when the duty count is reached.
0
PPOL0
Pulse Width Channel 0 Polarity
0 PWM channel 0 output is low at the beginning of the period, then goes high when the duty count is reached
1 PWM channel 0 output is high at the beginning of the period, then goes low when the duty count is reached.
Module Base + 0x0002
76543210
R0 0 PCLK5 PCLK4 PCLK3 PCLK2 PCLK1 PCLK0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-5. PWM Clock Select Register (PWMCLK)
Table 12-3. PWMPOL Field Descriptions (continued)
Field Description
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
356 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
12.3.2.4 PWM Prescale Clock Select Register (PWMPRCLK)
This register selects the prescale clock source for clocks A and B independently.
Read: anytime
Write: anytime
NOTE
PCKB2–PCKB0 and PCKA2–PCKA0 register bits can be written anytime.
If the clock prescale is changed while a PWM signal is being generated, a
truncated or stretched pulse can occur during the transition.
Table 12-4. PWMCLK Field Descriptions
Field Description
5
PCLK5
Pulse Width Channel 5 Clock Select
0 Clock A is the clock source for PWM channel 5.
1 Clock SA is the clock source for PWM channel 5.
4
PCLK4
Pulse Width Channel 4 Clock Select
0 Clock A is the clock source for PWM channel 4.
1 Clock SA is the clock source for PWM channel 4.
3
PCLK3
Pulse Width Channel 3 Clock Select
0 Clock B is the clock source for PWM channel 3.
1 Clock SB is the clock source for PWM channel 3.
2
PCLK2
Pulse Width Channel 2 Clock Select
0 Clock B is the clock source for PWM channel 2.
1 Clock SB is the clock source for PWM channel 2.
1
PCLK1
Pulse Width Channel 1 Clock Select
0 Clock A is the clock source for PWM channel 1.
1 Clock SA is the clock source for PWM channel 1.
0
PCLK0
Pulse Width Channel 0 Clock Select
0 Clock A is the clock source for PWM channel 0.
1 Clock SA is the clock source for PWM channel 0.
Module Base + 0x0003
76543210
R0 PCKB2 PCKB1 PCKB0 0PCKA2 PCKA1 PCKA0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-6. PWM Prescaler Clock Select Register (PWMPRCLK)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 357
Rev 01.24
12.3.2.5 PWM Center Align Enable Register (PWMCAE)
The PWMCAE register contains six control bits for the selection of center aligned outputs or left aligned
outputs for each PWM channel. If the CAEx bit is set to a 1, the corresponding PWM output will be center
aligned. If the CAEx bit is cleared, the corresponding PWM output will be left aligned. Reference
Section 12.4.2.5, “Left Aligned Outputs,” and Section 12.4.2.6, “Center Aligned Outputs,” for a more
detailed description of the PWM output modes.
Table 12-5. PWMPRCLK Field Descriptions
Field Description
6:5
PCKB[2:0]
Prescaler Select for Clock B — Clock B is 1 of two clock sources which can be used for channels 2 or 3. These
three bits determine the rate of clock B, as shown in Table 12-6.
2:0
PCKA[2:0]
Prescaler Select for Clock A — Clock A is 1 of two clock sources which can be used for channels 0, 1, 4, or 5.
These three bits determine the rate of clock A, as shown in Table 12-7.
Table 12-6. Clock B Prescaler Selects
PCKB2 PCKB1 PCKB0 Value of Clock B
0 0 0 Bus Clock
0 0 1 Bus Clock / 2
0 1 0 Bus Clock / 4
0 1 1 Bus Clock / 8
1 0 0 Bus Clock / 16
1 0 1 Bus Clock / 32
1 1 0 Bus Clock / 64
1 1 1 Bus Clock / 128
Table 12-7. Clock A Prescaler Selects
PCKA2 PCKA1 PCKA0 Value of Clock A
0 0 0 Bus Clock
0 0 1 Bus Clock / 2
0 1 0 Bus Clock / 4
0 1 1 Bus Clock / 8
1 0 0 Bus Clock / 16
1 0 1 Bus Clock / 32
1 1 0 Bus Clock / 64
1 1 1 Bus Clock / 128
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
358 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Read: anytime
Write: anytime
NOTE
Write these bits only when the corresponding channel is disabled.
12.3.2.6 PWM Control Register (PWMCTL)
The PWMCTL register provides for various control of the PWM module.
Module Base + 0x0004
76543210
R0 0 CAE5 CAE4 CAE3 CAE2 CAE1 CAE0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-7. PWM Center Align Enable Register (PWMCAE)
Table 12-8. PWMCAE Field Descriptions
Field Description
5
CAE5
Center Aligned Output Mode on Channel 5
0 Channel 5 operates in left aligned output mode.
1 Channel 5 operates in center aligned output mode.
4
CAE4
Center Aligned Output Mode on Channel 4
0 Channel 4 operates in left aligned output mode.
1 Channel 4 operates in center aligned output mode.
3
CAE3
Center Aligned Output Mode on Channel 3
1 Channel 3 operates in left aligned output mode.
1 Channel 3 operates in center aligned output mode.
2
CAE2
Center Aligned Output Mode on Channel 2
0 Channel 2 operates in left aligned output mode.
1 Channel 2 operates in center aligned output mode.
1
CAE1
Center Aligned Output Mode on Channel 1
0 Channel 1 operates in left aligned output mode.
1 Channel 1 operates in center aligned output mode.
0
CAE0
Center Aligned Output Mode on Channel 0
0 Channel 0 operates in left aligned output mode.
1 Channel 0 operates in center aligned output mode.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 359
Rev 01.24
Read: anytime
Write: anytime
There are three control bits for concatenation, each of which is used to concatenate a pair of PWM
channels into one 16-bit channel. When channels 4 and 5 are concatenated, channel 4 registers become the
high-order bytes of the double-byte channel. When channels 2 and 3 are concatenated, channel 2 registers
become the high-order bytes of the double-byte channel. When channels 0 and 1 are concatenated,
channel 0 registers become the high-order bytes of the double-byte channel.
Reference Section 12.4.2.7, “PWM 16-Bit Functions,”for a more detailed description of the concatenation
PWM function.
NOTE
Change these bits only when both corresponding channels are disabled.
Module Base + 0x0005
76543210
R0 CON45 CON23 CON01 PSWAI PFRZ 00
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-8. PWM Control Register (PWMCTL)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
360 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 12-9. PWMCTL Field Descriptions
Field Description
6
CON45
Concatenate Channels 4 and 5
0 Channels 4 and 5 are separate 8-bit PWMs.
1 Channels 4 and 5 are concatenated to create one 16-bit PWM channel. Channel 4 becomes the high-order
byte and channel 5 becomes the low-order byte. Channel 5 output pin is used as the output for this 16-bit PWM
(bit 5 of port PWMP). Channel 5 clock select control bit determines the clock source, channel 5 polarity bit
determines the polarity, channel 5 enable bit enables the output and channel 5 center aligned enable bit
determines the output mode.
5
CON23
Concatenate Channels 2 and 3
0 Channels 2 and 3 are separate 8-bit PWMs.
1 Channels 2 and 3 are concatenated to create one 16-bit PWM channel. Channel 2 becomes the high-order
byte and channel 3 becomes the low-order byte. Channel 3 output pin is used as the output for this 16-bit PWM
(bit 3 of port PWMP). Channel 3 clock select control bit determines the clock source, channel 3 polarity bit
determines the polarity, channel 3 enable bit enables the output and channel 3 center aligned enable bit
determines the output mode.
4
CON01
Concatenate Channels 0 and 1
0 Channels 0 and 1 are separate 8-bit PWMs.
1 Channels 0 and 1 are concatenated to create one 16-bit PWM channel. Channel 0 becomes the high-order
byte and channel 1 becomes the low-order byte. Channel 1 output pin is used as the output for this 16-bit PWM
(bit 1 of port PWMP). Channel 1 clock select control bit determines the clock source, channel 1 polarity bit
determines the polarity, channel 1 enable bit enables the output and channel 1 center aligned enable bit
determines the output mode.
3
PSWAI
PWM Stops in Wait Mode — Enabling this bit allows for lower power consumption in wait mode by disabling the
input clock to the prescaler.
0 Allow the clock to the prescaler to continue while in wait mode.
1 Stop the input clock to the prescaler whenever the MCU is in wait mode.
2
PFRZ
PWM Counters Stop in Freeze Mode — In freeze mode, there is an option to disable the input clock to the
prescaler by setting the PFRZ bit in the PWMCTL register. If this bit is set, whenever the MCU is in freeze mode
the input clock to the prescaler is disabled. This feature is useful during emulation as it allows the PWM function
to be suspended. In this way, the counters of the PWM can be stopped while in freeze mode so that after normal
program flow is continued, the counters are re-enabled to simulate real-time operations. Because the registers
remain accessible in this mode, to re-enable the prescaler clock, either disable the PFRZ bit or exit freeze mode.
0 Allow PWM to continue while in freeze mode.
1 Disable PWM input clock to the prescaler whenever the part is in freeze mode. This is useful for emulation.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 361
Rev 01.24
12.3.2.7 Reserved Register (PWMTST)
This register is reserved for factory testing of the PWM module and is not available in normal modes.
Read: always read 0x0000 in normal modes
Write: unimplemented in normal modes
NOTE
Writing to this register when in special modes can alter the PWM
functionality.
12.3.2.8 Reserved Register (PWMPRSC)
This register is reserved for factory testing of the PWM module and is not available in normal modes.
Read: always read 0x0000 in normal modes
Write: unimplemented in normal modes
NOTE
Writing to this register when in special modes can alter the PWM
functionality.
Module Base + 0x0006
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-9. Reserved Register (PWMTST)
Module Base + 0x0007
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-10. Reserved Register (PWMPRSC)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
362 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
12.3.2.9 PWM Scale A Register (PWMSCLA)
PWMSCLA is the programmable scale value used in scaling clock A to generate clock SA. Clock SA is
generated by taking clock A, dividing it by the value in the PWMSCLA register and dividing that by two.
Clock SA = Clock A / (2 * PWMSCLA)
NOTE
When PWMSCLA = 0x0000, PWMSCLA value is considered a full scale
value of 256. Clock A is thus divided by 512.
Any value written to this register will cause the scale counter to load the new scale value (PWMSCLA).
Read: anytime
Write: anytime (causes the scale counter to load the PWMSCLA value)
12.3.2.10 PWM Scale B Register (PWMSCLB)
PWMSCLB is the programmable scale value used in scaling clock B to generate clock SB. Clock SB is
generated by taking clock B, dividing it by the value in the PWMSCLB register and dividing that by two.
Clock SB = Clock B / (2 * PWMSCLB)
NOTE
When PWMSCLB = 0x0000, PWMSCLB value is considered a full scale
value of 256. Clock B is thus divided by 512.
Any value written to this register will cause the scale counter to load the new scale value (PWMSCLB).
Read: anytime
Write: anytime (causes the scale counter to load the PWMSCLB value).
Module Base + 0x0008
76543210
RBit 7 6 5 4 3 2 1 Bit 0
W
Reset 0 0 0 00000
Figure 12-11. PWM Scale A Register (PWMSCLA)
Module Base + 0x0009
76543210
RBit 7 6 5 4 3 2 1 Bit 0
W
Reset 0 0 0 00000
Figure 12-12. PWM Scale B Register (PWMSCLB)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 363
Rev 01.24
12.3.2.11 Reserved Registers (PWMSCNTx)
The registers PWMSCNTA and PWMSCNTB are reserved for factory testing of the PWM module and
are not available in normal modes.
Read: always read 0x0000 in normal modes
Write: unimplemented in normal modes
NOTE
Writing to these registers when in special modes can alter the PWM
functionality.
Module Base + 0x000A
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-13. Reserved Register (PWMSCNTA)
Module Base + 0x000B
76543210
R00000000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-14. Reserved Register (PWMSCNTB)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
364 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
12.3.2.12 PWM Channel Counter Registers (PWMCNTx)
Each channel has a dedicated 8-bit up/down counter which runs at the rate of the selected clock source.
The counter can be read at any time without affecting the count or the operation of the PWM channel. In
left aligned output mode, the counter counts from 0 to the value in the period register – 1. In center aligned
output mode, the counter counts from 0 up to the value in the period register and then back down to 0.
Any value written to the counter causes the counter to reset to 0x0000, the counter direction to be set to
up, the immediate load of both duty and period registers with values from the buffers, and the output to
change according to the polarity bit. The counter is also cleared at the end of the effective period (see
Section 12.4.2.5, “Left Aligned Outputs,” and Section 12.4.2.6, “Center Aligned Outputs,” for more
details). When the channel is disabled (PWMEx = 0), the PWMCNTx register does not count. When a
channel becomes enabled (PWMEx = 1), the associated PWM counter starts at the count in the
PWMCNTx register. For more detailed information on the operation of the counters, reference
Section 12.4.2.4, “PWM Timer Counters.”
In concatenated mode, writes to the 16-bit counter by using a 16-bit access or writes to either the low- or
high-order byte of the counter will reset the 16-bit counter. Reads of the 16-bit counter must be made by
16-bit access to maintain data coherency.
NOTE
Writing to the counter while the channel is enabled can cause an irregular
PWM cycle to occur.
Module Base + 0x000C
76543210
R Bit 7 6 5 4321Bit 0
W00000000
Reset 0 0 0 00000
Figure 12-15. PWM Channel Counter Registers (PWMCNT0)
Module Base + 0x000D
76543210
R Bit 7 6 5 4321Bit 0
W00000000
Reset 0 0 0 00000
Figure 12-16. PWM Channel Counter Registers (PWMCNT1)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 365
Rev 01.24
Read: anytime
Write: anytime (any value written causes PWM counter to be reset to 0x0000).
12.3.2.13 PWM Channel Period Registers (PWMPERx)
There is a dedicated period register for each channel. The value in this register determines the period of
the associated PWM channel.
The period registers for each channel are double buffered so that if they change while the channel is
enabled, the change will NOT take effect until one of the following occurs:
• The effective period ends
• The counter is written (counter resets to 0x0000)
Module Base + 0x000E
76543210
R Bit 7 6 5 4321Bit 0
W00000000
Reset 0 0 0 00000
Figure 12-17. PWM Channel Counter Registers (PWMCNT2)
Module Base + 0x000F
76543210
R Bit 7 6 5 4321Bit 0
W00000000
Reset 0 0 0 00000
Figure 12-18. PWM Channel Counter Registers (PWMCNT3)
Module Base + 0x00010
76543210
R Bit 7 6 5 4321Bit 0
W00000000
Reset 0 0 0 00000
Figure 12-19. PWM Channel Counter Registers (PWMCNT4)
Module Base + 0x00011
76543210
R Bit 7 6 5 4321Bit 0
W00000000
Reset 0 0 0 00000
Figure 12-20. PWM Channel Counter Registers (PWMCNT5)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
366 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
• The channel is disabled
In this way, the output of the PWM will always be either the old waveform or the new waveform, not some
variation in between. If the channel is not enabled, then writes to the period register will go directly to the
latches as well as the buffer.
NOTE
Reads of this register return the most recent value written. Reads do not
necessarily return the value of the currently active period due to the double
buffering scheme.
Reference Section 12.4.2.3, “PWM Period and Duty,” for more information.
To calculate the output period, take the selected clock source period for the channel of interest (A, B, SA,
or SB) and multiply it by the value in the period register for that channel:
• Left aligned output (CAEx = 0)
• PWMx period = channel clock period * PWMPERx center aligned output (CAEx = 1)
• PWMx period = channel clock period * (2 * PWMPERx)
For boundary case programming values, please refer to Section 12.4.2.8, “PWM Boundary Cases.”
Module Base + 0x0012
76543210
RBit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 12-21. PWM Channel Period Registers (PWMPER0)
Module Base + 0x0013
76543210
RBit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 12-22. PWM Channel Period Registers (PWMPER1)
Module Base + 0x0014
76543210
RBit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 12-23. PWM Channel Period Registers (PWMPER2)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 367
Rev 01.24
Read: anytime
Write: anytime
12.3.2.14 PWM Channel Duty Registers (PWMDTYx)
There is a dedicated duty register for each channel. The value in this register determines the duty of the
associated PWM channel. The duty value is compared to the counter and if it is equal to the counter value
a match occurs and the output changes state.
The duty registers for each channel are double buffered so that if they change while the channel is enabled,
the change will NOT take effect until one of the following occurs:
• The effective period ends
• The counter is written (counter resets to 0x0000)
• The channel is disabled
In this way, the output of the PWM will always be either the old duty waveform or the new duty waveform,
not some variation in between. If the channel is not enabled, then writes to the duty register will go directly
to the latches as well as the buffer.
Module Base + 0x0015
76543210
RBit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 12-24. PWM Channel Period Registers (PWMPER3)
Module Base + 0x0016
76543210
RBit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 12-25. PWM Channel Period Registers (PWMPER4)
Module Base + 0x0017
76543210
RBit 7 6 5 4321Bit 0
W
Reset 0 0 0 00000
Figure 12-26. PWM Channel Period Registers (PWMPER5)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
368 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
NOTE
Reads of this register return the most recent value written. Reads do not
necessarily return the value of the currently active duty due to the double
buffering scheme.
Reference Section 12.4.2.3, “PWM Period and Duty,” for more information.
NOTE
Depending on the polarity bit, the duty registers will contain the count of
either the high time or the low time. If the polarity bit is 1, the output starts
high and then goes low when the duty count is reached, so the duty registers
contain a count of the high time. If the polarity bit is 0, the output starts low
and then goes high when the duty count is reached, so the duty registers
contain a count of the low time.
To calculate the output duty cycle (high time as a % of period) for a particular channel:
• Polarity = 0 (PPOLx = 0)
Duty cycle = [(PWMPERx PWMDTYx)/PWMPERx] * 100%
• Polarity = 1 (PPOLx = 1)
Duty cycle = [PWMDTYx / PWMPERx] * 100%
• For boundary case programming values, please refer to Section 12.4.2.8, “PWM Boundary Cases.”
Module Base + 0x0018
76543210
RBit 7 6 5 4321Bit 0
W
Reset 1 1 1 11111
Figure 12-27. PWM Channel Duty Registers (PWMDTY0)
Module Base + 0x0019
76543210
RBit 7 6 5 4321Bit 0
W
Reset 1 1 1 11111
Figure 12-28. PWM Channel Duty Registers (PWMDTY1)
Module Base + 0x001A
76543210
RBit 7 6 5 4321Bit 0
W
Reset 1 1 1 11111
Figure 12-29. PWM Channel Duty Registers (PWMDTY2)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 369
Rev 01.24
Read: anytime
Write: anytime
12.3.2.15 PWM Shutdown Register (PWMSDN)
The PWMSDN register provides for the shutdown functionality of the PWM module in the emergency
cases.
Read: anytime
Write: anytime
Module Base + 0x001B
76543210
RBit 7 6 5 4321Bit 0
W
Reset 1 1 1 11111
Figure 12-30. PWM Channel Duty Registers (PWMDTY3)
Module Base + 0x001C
76543210
RBit 7 6 5 4321Bit 0
W
Reset 1 1 1 11111
Figure 12-31. PWM Channel Duty Registers (PWMDTY4)
Module Base + 0x001D
76543210
RBit 7 6 5 4321Bit 0
W
Reset 1 1 1 11111
Figure 12-32. PWM Channel Duty Registers (PWMDTY5)
Module Base + 0x00E
76543210
RPWMIF PWMIE 0PWMLVL 0 PWM5IN PWM5INL PWM5ENA
W PWMRSTRT
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 12-33. PWM Shutdown Register (PWMSDN)
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
370 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 12-10. PWMSDN Field Descriptions
Field Description
7
PWMIF
PWM Interrupt Flag — Any change from passive to asserted (active) state or from active to passive state will be
flagged by setting the PWMIF flag = 1. The flag is cleared by writing a logic 1 to it. Writing a 0 has no effect.
0 No change on PWM5IN input.
1 Change on PWM5IN input
6
PWMIE
PWM Interrupt Enable — If interrupt is enabled an interrupt to the CPU is asserted.
0 PWM interrupt is disabled.
1 PWM interrupt is enabled.
5
PWMRSTRT
PWM Restart — The PWM can only be restarted if the PWM channel input 5 is deasserted. After writing a logic 1
to the PWMRSTRT bit (trigger event) the PWM channels start running after the corresponding counter passes
next “counter = 0” phase.
Also, if the PWM5ENA bit is reset to 0, the PWM do not start before the counter passes 0x0000.
The bit is always read as 0.
4
PWMLVL
PWM Shutdown Output Level — If active level as defined by the PWM5IN input, gets asserted all enabled PWM
channels are immediately driven to the level defined by PWMLVL.
0 PWM outputs are forced to 0
1 PWM outputs are forced to 1.
2
PWM5IN
PWM Channel 5 Input Status — This reflects the current status of the PWM5 pin.
1
PWM5INL
PWM Shutdown Active Input Level for Channel 5 — If the emergency shutdown feature is enabled
(PWM5ENA = 1), this bit determines the active level of the PWM5 channel.
0 Active level is low
1 Active level is high
0
PWM5ENA
PWM Emergency Shutdown Enable — If this bit is logic 1 the pin associated with channel 5 is forced to input
and the emergency shutdown feature is enabled. All the other bits in this register are meaningful only if
PWM5ENA = 1.
0 PWM emergency feature disabled.
1 PWM emergency feature is enabled.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 371
Rev 01.24
12.4 Functional Description
12.4.1 PWM Clock Select
There are four available clocks called clock A, clock B, clock SA (scaled A), and clock SB (scaled B).
These four clocks are based on the bus clock.
Clock A and B can be software selected to be 1, 1/2, 1/4, 1/8,..., 1/64, 1/128 times the bus clock. Clock SA
uses clock A as an input and divides it further with a reloadable counter. Similarly, clock SB uses clock B
as an input and divides it further with a reloadable counter. The rates available for clock SA are software
selectable to be clock A divided by 2, 4, 6, 8, ..., or 512 in increments of divide by 2. Similar rates are
available for clock SB. Each PWM channel has the capability of selecting one of two clocks, either the
pre-scaled clock (clock A or B) or the scaled clock (clock SA or SB).
The block diagram in Figure 12-34 shows the four different clocks and how the scaled clocks are created.
12.4.1.1 Prescale
The input clock to the PWM prescaler is the bus clock. It can be disabled whenever the part is in freeze
mode by setting the PFRZ bit in the PWMCTL register. If this bit is set, whenever the MCU is in freeze
mode the input clock to the prescaler is disabled. This is useful for emulation in order to freeze the PWM.
The input clock can also be disabled when all six PWM channels are disabled (PWME5–PWME0 = 0)
This is useful for reducing power by disabling the prescale counter.
Clock A and clock B are scaled values of the input clock. The value is software selectable for both clock A
and clock B and has options of 1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, or 1/128 times the bus clock. The value
selected for clock A is determined by the PCKA2, PCKA1, and PCKA0 bits in the PWMPRCLK register.
The value selected for clock B is determined by the PCKB2, PCKB1, and PCKB0 bits also in the
PWMPRCLK register.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
372 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 12-34. PWM Clock Select Block Diagram
2
4 8 16 32 64 128
PCKB2
PCKB1
PCKB0
M
U
X
Clock A
Clock B
Clock SA
Clock A/2, A/4, A/6,....A/512
PRESCALE SCALE
Divide by Prescaler Taps:
PFRZ
FREEZE
Bus Clock
CLOCK SELECT
M
U
X
PCLK0
Clock to
PWM Ch 0
M
U
X
PCLK2
Clock to
PWM Ch 2
M
U
X
PCLK1
Clock to
PWM Ch 1
M
U
X
PCLK4
Clock to
PWM Ch 4
M
U
X
PCLK5
Clock to
PWM Ch 5
M
U
X
PCLK3
Clock to
PWM Ch 3
Load
DIV 2
PWMSCLB
8-Bit Down Counter
Clock SB
Clock B/2, B/4, B/6,....B/512
M
U
X
PCKA2
PCKA1
PCKA0
PWME5:0
Count = 1
Load
DIV 2
PWMSCLA
8-Bit Down Counter Count = 1
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 373
Rev 01.24
12.4.1.2 Clock Scale
The scaled A clock uses clock A as an input and divides it further with a user programmable value and
then divides this by 2. The scaled B clock uses clock B as an input and divides it further with a user
programmable value and then divides this by 2. The rates available for clock SA are software selectable
to be clock A divided by 2, 4, 6, 8, ..., or 512 in increments of divide by 2. Similar rates are available for
clock SB.
Clock A is used as an input to an 8-bit down counter. This down counter loads a user programmable scale
value from the scale register (PWMSCLA). When the down counter reaches 1, two things happen; a pulse
is output and the 8-bit counter is re-loaded. The output signal from this circuit is further divided by two.
This gives a greater range with only a slight reduction in granularity. Clock SA equals clock A divided by
two times the value in the PWMSCLA register.
NOTE
Clock SA = Clock A / (2 * PWMSCLA)
When PWMSCLA = 0x0000, PWMSCLA value is considered a full scale
value of 256. Clock A is thus divided by 512.
Similarly, clock B is used as an input to an 8-bit down counter followed by a divide by two producing clock
SB. Thus, clock SB equals clock B divided by two times the value in the PWMSCLB register.
NOTE
Clock SB = Clock B / (2 * PWMSCLB)
When PWMSCLB = 0x0000, PWMSCLB value is considered a full scale
value of 256. Clock B is thus divided by 512.
As an example, consider the case in which the user writes 0x00FF into the PWMSCLA register. Clock A
for this case will be bus clock divided by 4. A pulse will occur at a rate of once every 255 x 4 bus cycles.
Passing this through the divide by two circuit produces a clock signal at a bus clock divided by 2040 rate.
Similarly, a value of 0x0001 in the PWMSCLA register when clock A is bus clock divided by 4 will
produce a bus clock divided by 8 rate.
Writing to PWMSCLA or PWMSCLB causes the associated 8-bit down counter to be re-loaded.
Otherwise, when changing rates the counter would have to count down to 0x0001 before counting at the
proper rate. Forcing the associated counter to re-load the scale register value every time PWMSCLA or
PWMSCLB is written prevents this.
NOTE
Writing to the scale registers while channels are operating can cause
irregularities in the PWM outputs.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
374 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
12.4.1.3 Clock Select
Each PWM channel has the capability of selecting one of two clocks. For channels 0, 1, 4, and 5 the clock
choices are clock A or clock SA. For channels 2 and 3 the choices are clock B or clock SB. The clock
selection is done with the PCLKx control bits in the PWMCLK register.
NOTE
Changing clock control bits while channels are operating can cause
irregularities in the PWM outputs.
12.4.2 PWM Channel Timers
The main part of the PWM module are the actual timers. Each of the timer channels has a counter, a period
register and a duty register (each are 8 bit). The waveform output period is controlled by a match between
the period register and the value in the counter. The duty is controlled by a match between the duty register
and the counter value and causes the state of the output to change during the period. The starting polarity
of the output is also selectable on a per channel basis. Figure 12-35 shows a block diagram for PWM timer.
Figure 12-35. PWM Timer Channel Block Diagram
Clock Source
T
R
Q
Q
M
U
X
PPOLx
From Port PWMP
Data Register
PWMEx
(clock edge sync)
To Pi n
Driver
GATE
8-Bit Compare =
PWMDTYx
8-Bit Compare =
PWMPERx
M
U
X
CAEx
up/down
T
R
Q
Q
reset
8-Bit Counter
PWMCNTx
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 375
Rev 01.24
12.4.2.1 PWM Enable
Each PWM channel has an enable bit (PWMEx) to start its waveform output. When any of the PWMEx
bits are set (PWMEx = 1), the associated PWM output signal is enabled immediately. However, the actual
PWM waveform is not available on the associated PWM output until its clock source begins its next cycle
due to the synchronization of PWMEx and the clock source. An exception to this is when channels are
concatenated. Refer to Section 12.4.2.7, “PWM 16-Bit Functions,” for more detail.
NOTE
The first PWM cycle after enabling the channel can be irregular.
On the front end of the PWM timer, the clock is enabled to the PWM circuit by the PWMEx bit being high.
There is an edge-synchronizing circuit to guarantee that the clock will only be enabled or disabled at an
edge. When the channel is disabled (PWMEx = 0), the counter for the channel does not count.
12.4.2.2 PWM Polarity
Each channel has a polarity bit to allow starting a waveform cycle with a high or low signal. This is shown
on the block diagram as a mux select of either the Q output or the Q output of the PWM output flip-flop.
When one of the bits in the PWMPOL register is set, the associated PWM channel output is high at the
beginning of the waveform, then goes low when the duty count is reached. Conversely, if the polarity bit
is 0, the output starts low and then goes high when the duty count is reached.
12.4.2.3 PWM Period and Duty
Dedicated period and duty registers exist for each channel and are double buffered so that if they change
while the channel is enabled, the change will NOT take effect until one of the following occurs:
• The effective period ends
• The counter is written (counter resets to 0x0000)
• The channel is disabled
In this way, the output of the PWM will always be either the old waveform or the new waveform, not some
variation in between. If the channel is not enabled, then writes to the period and duty registers will go
directly to the latches as well as the buffer.
A change in duty or period can be forced into effect “immediately” by writing the new value to the duty
and/or period registers and then writing to the counter. This forces the counter to reset and the new duty
and/or period values to be latched. In addition, because the counter is readable it is possible to know where
the count is with respect to the duty value and software can be used to make adjustments.
NOTE
When forcing a new period or duty into effect immediately, an irregular
PWM cycle can occur.
Depending on the polarity bit, the duty registers will contain the count of
either the high time or the low time.
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
376 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
12.4.2.4 PWM Timer Counters
Each channel has a dedicated 8-bit up/down counter which runs at the rate of the selected clock source
(reference Figure 12-34 for the available clock sources and rates). The counter compares to two registers,
a duty register and a period register as shown in Figure 12-35. When the PWM counter matches the duty
register the output flip-flop changes state causing the PWM waveform to also change state. A match
between the PWM counter and the period register behaves differently depending on what output mode is
selected as shown in Figure 12-35 and described in Section 12.4.2.5, “Left Aligned Outputs,” and
Section 12.4.2.6, “Center Aligned Outputs.”
Each channel counter can be read at anytime without affecting the count or the operation of the PWM
channel.
Any value written to the counter causes the counter to reset to 0x0000, the counter direction to be set to
up, the immediate load of both duty and period registers with values from the buffers, and the output to
change according to the polarity bit. When the channel is disabled (PWMEx = 0), the counter stops. When
a channel becomes enabled (PWMEx = 1), the associated PWM counter continues from the count in the
PWMCNTx register. This allows the waveform to resume when the channel is re-enabled. When the
channel is disabled, writing 0 to the period register will cause the counter to reset on the next selected
clock.
NOTE
If the user wants to start a new “clean” PWM waveform without any
“history” from the old waveform, the user must write to channel counter
(PWMCNTx) prior to enabling the PWM channel (PWMEx = 1).
Generally, writes to the counter are done prior to enabling a channel to start from a known state. However,
writing a counter can also be done while the PWM channel is enabled (counting). The effect is similar to
writing the counter when the channel is disabled except that the new period is started immediately with
the output set according to the polarity bit.
NOTE
Writing to the counter while the channel is enabled can cause an irregular
PWM cycle to occur.
The counter is cleared at the end of the effective period (see Section 12.4.2.5, “Left Aligned Outputs,”and
Section 12.4.2.6, “Center Aligned Outputs,” for more details).
Table 12-11. PWM Timer Counter Conditions
Counter Clears (0x0000) Counter Counts Counter Stops
When PWMCNTx register
written to any value
When PWM channel is
enabled (PWMEx = 1). Counts
from last value in PWMCNTx.
When PWM channel is
disabled (PWMEx = 0)
Effective period ends
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 377
Rev 01.24
12.4.2.5 Left Aligned Outputs
The PWM timer provides the choice of two types of outputs, left aligned or center aligned outputs. They
are selected with the CAEx bits in the PWMCAE register. If the CAEx bit is cleared (CAEx = 0), the
corresponding PWM output will be left aligned.
In left aligned output mode, the 8-bit counter is configured as an up counter only. It compares to two
registers, a duty register and a period register as shown in the block diagram in Figure 12-35. When the
PWM counter matches the duty register the output flip-flop changes state causing the PWM waveform to
also change state. A match between the PWM counter and the period register resets the counter and the
output flip-flop as shown in Figure 12-35 as well as performing a load from the double buffer period and
duty register to the associated registers as described in Section 12.4.2.3, “PWM Period and Duty.” The
counter counts from 0 to the value in the period register – 1.
NOTE
Changing the PWM output mode from left aligned output to center aligned
output (or vice versa) while channels are operating can cause irregularities
in the PWM output. It is recommended to program the output mode before
enabling the PWM channel.
Figure 12-36. PWM Left Aligned Output Waveform
To calculate the output frequency in left aligned output mode for a particular channel, take the selected
clock source frequency for the channel (A, B, SA, or SB) and divide it by the value in the period register
for that channel.
• PWMx frequency = clock (A, B, SA, or SB) / PWMPERx
• PWMx duty cycle (high time as a% of period):
— Polarity = 0 (PPOLx = 0)
Duty cycle = [(PWMPERx-PWMDTYx)/PWMPERx] * 100%
— Polarity = 1 (PPOLx = 1)
Duty cycle = [PWMDTYx / PWMPERx] * 100%
As an example of a left aligned output, consider the following case:
Clock source = bus clock, where bus clock = 10 MHz (100 ns period)
PPOLx = 0
PWMPERx = 4
PWMDTYx = 1
PWMx frequency = 10 MHz/4 = 2.5 MHz
PWMx period = 400 ns
PWMx duty cycle = 3/4 *100% = 75%
PWMDTYx
Period = PWMPERx
PPOLx = 0
PPOLx = 1
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
378 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Shown below is the output waveform generated.
Figure 12-37. PWM Left Aligned Output Example Waveform
12.4.2.6 Center Aligned Outputs
For center aligned output mode selection, set the CAEx bit (CAEx = 1) in the PWMCAE register and the
corresponding PWM output will be center aligned.
The 8-bit counter operates as an up/down counter in this mode and is set to up whenever the counter is
equal to 0x0000. The counter compares to two registers, a duty register and a period register as shown in
the block diagram in Figure 12-35. When the PWM counter matches the duty register the output flip-flop
changes state causing the PWM waveform to also change state. A match between the PWM counter and
the period register changes the counter direction from an up-count to a down-count. When the PWM
counter decrements and matches the duty register again, the output flip-flop changes state causing the
PWM output to also change state. When the PWM counter decrements and reaches 0, the counter direction
changes from a down-count back to an up-count and a load from the double buffer period and duty
registers to the associated registers is performed as described in Section 12.4.2.3, “PWM Period and
Duty.” The counter counts from 0 up to the value in the period register and then back down to 0. Thus the
effective period is PWMPERx*2.
NOTE
Changing the PWM output mode from left aligned output to center aligned
output (or vice versa) while channels are operating can cause irregularities
in the PWM output. It is recommended to program the output mode before
enabling the PWM channel.
Figure 12-38. PWM Center Aligned Output Waveform
E = 100 ns
DUTY CYCLE = 75%
PERIOD = 400 ns
PPOLx = 0
PPOLx = 1
PWMDTYx PWMDTYx
Period = PWMPERx*2
PWMPERx PWMPERx
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 379
Rev 01.24
To calculate the output frequency in center aligned output mode for a particular channel, take the selected
clock source frequency for the channel (A, B, SA, or SB) and divide it by twice the value in the period
register for that channel.
• PWMx frequency = clock (A, B, SA, or SB) / (2*PWMPERx)
• PWMx duty cycle (high time as a% of period):
— Polarity = 0 (PPOLx = 0)
Duty cycle = [(PWMPERx-PWMDTYx)/PWMPERx] * 100%
— Polarity = 1 (PPOLx = 1)
Duty cycle = [PWMDTYx / PWMPERx] * 100%
As an example of a center aligned output, consider the following case:
Clock source = bus clock, where bus clock = 10 MHz (100 ns period)
PPOLx = 0
PWMPERx = 4
PWMDTYx = 1
PWMx frequency = 10 MHz/8 = 1.25 MHz
PWMx period = 800 ns
PWMx duty cycle = 3/4 *100% = 75%
Shown below is the output waveform generated.
Figure 12-39. PWM Center Aligned Output Example Waveform
12.4.2.7 PWM 16-Bit Functions
The PWM timer also has the option of generating 6-channels of 8-bits or 3-channels of 16-bits for greater
PWM resolution}. This 16-bit channel option is achieved through the concatenation of two 8-bit channels.
The PWMCTL register contains three control bits, each of which is used to concatenate a pair of PWM
channels into one 16-bit channel. Channels 4 and 5 are concatenated with the CON45 bit, channels 2 and 3
are concatenated with the CON23 bit, and channels 0 and 1 are concatenated with the CON01 bit.
NOTE
Change these bits only when both corresponding channels are disabled.
When channels 4 and 5 are concatenated, channel 4 registers become the high-order bytes of the double
byte channel as shown in Figure 12-40. Similarly, when channels 2 and 3 are concatenated, channel 2
registers become the high-order bytes of the double byte channel. When channels 0 and 1 are concatenated,
channel 0 registers become the high-order bytes of the double byte channel.
E = 100 ns E = 100 ns
PERIOD = 800 ns
DUTY CYCLE = 75%
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
380 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 12-40. PWM 16-Bit Mode
When using the 16-bit concatenated mode, the clock source is determined by the low-order 8-bit channel
clock select control bits. That is channel 5 when channels 4 and 5 are concatenated, channel 3 when
channels 2 and 3 are concatenated, and channel 1 when channels 0 and 1 are concatenated. The resulting
PWM is output to the pins of the corresponding low-order 8-bit channel as also shown in Figure 12-40.
The polarity of the resulting PWM output is controlled by the PPOLx bit of the corresponding low-order
8-bit channel as well.
After concatenated mode is enabled (CONxx bits set in PWMCTL register), enabling/disabling the
corresponding 16-bit PWM channel is controlled by the low-order PWMEx bit. In this case, the high-order
bytes PWMEx bits have no effect and their corresponding PWM output is disabled.
In concatenated mode, writes to the 16-bit counter by using a 16-bit access or writes to either the low or
high-order byte of the counter will reset the 16-bit counter. Reads of the 16-bit counter must be made by
16-bit access to maintain data coherency.
Either left aligned or center aligned output mode can be used in concatenated mode and is controlled by
the low-order CAEx bit. The high-order CAEx bit has no effect.
PWMCNT4 PWCNT5
PWM5
Clock Source 5
High Low
Period/Duty Compare
PWMCNT2 PWCNT3
PWM3
Clock Source 3
High Low
Period/Duty Compare
PWMCNT0 PWCNT1
PWM1
Clock Source 1
High Low
Period/Duty Compare
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 381
Rev 01.24
Table 12-12 is used to summarize which channels are used to set the various control bits when in 16-bit
mode.
12.4.2.8 PWM Boundary Cases
Table 12-13 summarizes the boundary conditions for the PWM regardless of the output mode (left aligned
or center aligned) and 8-bit (normal) or 16-bit (concatenation):
12.5 Resets
The reset state of each individual bit is listed within the register description section (see Section 12.3,
“Memory Map and Register Definition,” which details the registers and their bit-fields. All special
functions or modes which are initialized during or just following reset are described within this section.
• The 8-bit up/down counter is configured as an up counter out of reset.
• All the channels are disabled and all the counters don’t count.
12.6 Interrupts
The PWM8B6CV1 module has only one interrupt which is generated at the time of emergency shutdown,
if the corresponding enable bit (PWMIE) is set. This bit is the enable for the interrupt. The interrupt flag
PWMIF is set whenever the input level of the PWM5 channel changes while PWM5ENA=1 or when
PWMENA is being asserted while the level at PWM5 is active.
A description of the registers involved and affected due to this interrupt is explained in Section 12.3.2.15,
“PWM Shutdown Register (PWMSDN).”
Table 12-12. 16-bit Concatenation Mode Summary
CONxx PWMEx PPOLx PCLKx CAEx PWMx Output
CON45 PWME5 PPOL5 PCLK5 CAE5 PWM5
CON23 PWME3 PPOL3 PCLK3 CAE3 PWM3
CON01 PWME1 PPOL1 PCLK1 CAE1 PWM1
Table 12-13. PWM Boundary Cases
PWMDTYx PWMPERx PPOLx PWMx Output
0x0000
(indicates no duty)
>0x0000 1 Always Low
0x0000
(indicates no duty)
>0x0000 0 Always High
XX 0x0000(1)
(indicates no period)
1. Counter = 0x0000 and does not count.
1 Always High
XX 0x00001
(indicates no period)
0 Always Low
>= PWMPERx XX 1 Always High
>= PWMPERx XX 0 Always Low
Chapter 12 Pulse-Width Modulator (PWM8B6CV1) Block Description
382 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 383
Rev 01.24
Chapter 13
Serial Communications Interface (S12SCIV2)
Block Description
13.1 Introduction
This block guide provide an overview of serial communication interface (SCI) module. The SCI allows
asynchronous serial communications with peripheral devices and other CPUs.
13.1.1 Glossary
IRQ — Interrupt Request
LSB — Least Significant Bit
MSB — Most Significant Bit
NRZ — Non-Return-to-Zero
RZI — Return-to-Zero-Inverted
RXD — Receive Pin
SCI — Serial Communication Interface
TXD — Transmit Pin
13.1.2 Features
The SCI includes these distinctive features:
• Full-duplex operation
• Standard mark/space non-return-to-zero (NRZ) format
• 13-bit baud rate selection
• Programmable 8-bit or 9-bit data format
• Separately enabled transmitter and receiver
• Programmable transmitter output parity
• Two receiver wake up methods:
— Idle line wake-up
— Address mark wake-up
• Interrupt-driven operation with eight flags:
— Transmitter empty
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
384 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
— Transmission complete
— Receiver full
— Idle receiver input
— Receiver overrun
— Noise error
— Framing error
— Parity error
• Receiver framing error detection
• Hardware parity checking
• 1/16 bit-time noise detection
13.1.3 Modes of Operation
The SCI operation is the same independent of device resource mapping and bus interface mode. Different
power modes are available to facilitate power saving.
13.1.3.1 Run Mode
Normal mode of operation.
13.1.3.2 Wait Mode
SCI operation in wait mode depends on the state of the SCISWAI bit in the SCI control register 1
(SCICR1).
• If SCISWAI is clear, the SCI operates normally when the CPU is in wait mode.
• If SCISWAI is set, SCI clock generation ceases and the SCI module enters a power-conservation
state when the CPU is in wait mode. Setting SCISWAI does not affect the state of the receiver
enable bit, RE, or the transmitter enable bit, TE.
• If SCISWAI is set, any transmission or reception in progress stops at wait mode entry. The
transmission or reception resumes when either an internal or external interrupt brings the CPU out
of wait mode. Exiting wait mode by reset aborts any transmission or reception in progress and
resets the SCI.
13.1.3.3 Stop Mode
The SCI is inactive during stop mode for reduced power consumption. The STOP instruction does not
affect the SCI register states, but the SCI module clock will be disabled. The SCI operation resumes from
where it left off after an external interrupt brings the CPU out of stop mode. Exiting stop mode by reset
aborts any transmission or reception in progress and resets the SCI.
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 385
Rev 01.24
13.1.4 Block Diagram
Figure 13-1 is a high level block diagram of the SCI module, showing the interaction of various functional
blocks.
Figure 13-1. SCI Block Diagram
13.2 External Signal Description
The SCI module has a total of two external pins:
13.2.1 TXD-SCI Transmit Pin
This pin serves as transmit data output of SCI.
13.2.2 RXD-SCI Receive Pin
This pin serves as receive data input of the SCI.
SCI DATA REGISTER
RECEIVE SHIFT REGISTER
RECEIVE & WAKE UP CONTROL
DATA FORMAT CONTROL
TRANSMIT CONTROL
TRANSMIT SHIFT REGISTER
SCI DATA REGISTER
BAUD
GENERATOR
RX DATA IN
÷16
BUS CLOCK
TXDATA OUT
IDLE IRQ
RDR/OR IRQ
TDRE IRQ
TC IRQ
ORING
IRQ GENERATION IRQ GENERATION
IRQ
TO CPU
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
386 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.3 Memory Map and Registers
This section provides a detailed description of all memory and registers.
13.3.1 Module Memory Map
The memory map for the SCI module is given below in Figure 13-2. The Address listed for each register
is the address offset. The total address for each register is the sum of the base address for the SCI module
and the address offset for each register.
13.3.2 Register Descriptions
This section consists of register descriptions in address order. Each description includes a standard register
diagram with an associated figure number. Writes to a reserved register location do not have any effect and
reads of these locations return a zero. Details of register bit and field function follow the register diagrams,
in bit order.
Address Name Bit 7 65432 1Bit 0
0x0000 SCIBDH R0 0 0 SBR12 SBR11 SBR10 SBR9 SBR8
W
0x0001 SCIBDL RSBR7 SBR6 SBR5 SBR4 SBR3 SBR2 SBR1 SBR0
W
0x0002 SCICR1 RLOOPS SCISWAI RSRC M WAKE ILT PE PT
W
0x0003 SCICR2 RTIE TCIE RIE ILIE TE RE RWU SBK
W
0x0004 SCISR1 R TDRE TC RDRF IDLE OR NF FE PF
W
0x0005 SCISR2 R0 0000
BRK13 TXDIR RAF
W
0x0006 SCIDRH RR8 T8 0000 0 0
W
0x0007 SCIDRL RR7 R6R5R4R3R2 R1 R0
WT7 T6T5T4T3T2 T1 T0
= Unimplemented or Reserved
Figure 13-2. SCI Register Summary
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 387
Rev 01.24
13.3.2.1 SCI Baud Rate Registers (SCIBDH and SCHBDL)
The SCI Baud Rate Register is used by the counter to determine the baud rate of the SCI. The formula for
calculating the baud rate is:
SCI baud rate = SCI module clock / (16 x BR)
where:
BR is the content of the SCI baud rate registers, bits SBR12 through SBR0. The baud rate registers
can contain a value from 1 to 8191.
Read: Anytime. If only SCIBDH is written to, a read will not return the correct data until SCIBDL is
written to as well, following a write to SCIBDH.
Write: Anytime
Module Base + 0x_0000
76543210
R000
SBR12 SBR11 SBR10 SBR9 SBR8
W
Reset 0 0 0 00000
Module Base + 0x_0001
76543210
R
SBR7 SBR6 SBR5 SBR4 SBR3 SBR2 SBR1 SBR0
W
Reset 0 0 0 00100
= Unimplemented or Reserved
Figure 13-3. SCI Baud Rate Registers (SCIBDH and SCIBDL)
Table 13-1. SCIBDH AND SCIBDL Field Descriptions
Field Description
4–0
7–0
SBR[12:0]
SCI Baud Rate Bits — The baud rate for the SCI is determined by these 13 bits.
Note: The baud rate generator is disabled until the TE bit or the RE bit is set for the first time after reset. The
baud rate generator is disabled when BR = 0.
Writing to SCIBDH has no effect without writing to SCIBDL, since writing to SCIBDH puts the data in a
temporary location until SCIBDL is written to.
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
388 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.3.2.2 SCI Control Register 1 (SCICR1)
Read: Anytime
Write: Anytime
Module Base + 0x_0002
76543210
R
LOOPS SCISWAI RSRC M WAKE ILT PE PT
W
Reset 0 0 0 00000
Figure 13-4. SCI Control Register 1 (SCICR1)
Table 13-2. SCICR1 Field Descriptions
Field Description
7
LOOPS
Loop Select Bit — LOOPS enables loop operation. In loop operation, the RXD pin is disconnected from the SCI
and the transmitter output is internally connected to the receiver input. Both the transmitter and the receiver must
be enabled to use the loop function.See Table 13-3.
0 Normal operation enabled
1 Loop operation enabled
Note: The receiver input is determined by the RSRC bit.
6
SCISWAI
SCI Stop in Wait Mode Bit — SCISWAI disables the SCI in wait mode.
0 SCI enabled in wait mode
1 SCI disabled in wait mode
5
RSRC
Receiver Source Bit — When LOOPS = 1, the RSRC bit determines the source for the receiver shift register
input.
0 Receiver input internally connected to transmitter output
1 Receiver input connected externally to transmitter
4
M
Data Format Mode Bit — MODE determines whether data characters are eight or nine bits long.
0 One start bit, eight data bits, one stop bit
1 One start bit, nine data bits, one stop bit
3
WAKE
Wakeup Condition Bit — WAKE determines which condition wakes up the SCI: a logic 1 (address mark) in the
most significant bit position of a received data character or an idle condition on the RXD.
0 Idle line wakeup
1 Address mark wakeup
2
ILT
Idle Line Type Bit — ILT determines when the receiver starts counting logic 1s as idle character bits. The
counting begins either after the start bit or after the stop bit. If the count begins after the start bit, then a string of
logic 1s preceding the stop bit may cause false recognition of an idle character. Beginning the count after the
stop bit avoids false idle character recognition, but requires properly synchronized transmissions.
0 Idle character bit count begins after start bit
1 Idle character bit count begins after stop bit
1
PE
Parity Enable Bit — PE enables the parity function. When enabled, the parity function inserts a parity bit in the
most significant bit position.
0 Parity function disabled
1 Parity function enabled
0
PT
Parity Type Bit — PT determines whether the SCI generates and checks for even parity or odd parity. With even
parity, an even number of 1s clears the parity bit and an odd number of 1s sets the parity bit. With odd parity, an
odd number of 1s clears the parity bit and an even number of 1s sets the parity bit.
0 Even parity
1 Odd parity
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 389
Rev 01.24
13.3.2.3 SCI Control Register 2 (SCICR2)
Read: Anytime
Write: Anytime
Table 13-3. Loop Functions
LOOPS RSRC Function
0 x Normal operation
1 0 Loop mode with Rx input internally connected to Tx output
1 1 Single-wire mode with Rx input connected to TXD
Module Base + 0x_0003
76543210
R
TIE TCIE RIE ILIE TE RE RWU SBK
W
Reset 0 0 0 00000
Figure 13-5. SCI Control Register 2 (SCICR2)
Table 13-4. SCICR2 Field Descriptions
Field Description
7
TIE
Transmitter Interrupt Enable Bit — TIE enables the transmit data register empty flag, TDRE, to generate
interrupt requests.
0 TDRE interrupt requests disabled
1 TDRE interrupt requests enabled
6
TCIE
Transmission Complete Interrupt Enable Bit — TCIE enables the transmission complete flag, TC, to generate
interrupt requests.
0 TC interrupt requests disabled
1 TC interrupt requests enabled
5
RIE
Receiver Full Interrupt Enable Bit — RIE enables the receive data register full flag, RDRF, or the overrun flag,
OR, to generate interrupt requests.
0 RDRF and OR interrupt requests disabled
1 RDRF and OR interrupt requests enabled
4
ILIE
Idle Line Interrupt Enable Bit — ILIE enables the idle line flag, IDLE, to generate interrupt requests.
0 IDLE interrupt requests disabled
1 IDLE interrupt requests enabled
3
TE
Transmitter Enable Bit — TE enables the SCI transmitter and configures the TXD pin as being controlled by
the SCI. The TE bit can be used to queue an idle preamble.
0 Transmitter disabled
1 Transmitter enabled
2
RE
Receiver Enable Bit — RE enables the SCI receiver.
0 Receiver disabled
1 Receiver enabled
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
390 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.3.2.4 SCI Status Register 1 (SCISR1)
The SCISR1 and SCISR2 registers provides inputs to the MCU for generation of SCI interrupts. Also,
these registers can be polled by the MCU to check the status of these bits. The flag-clearing procedures
require that the status register be read followed by a read or write to the SCI Data Register.It is permissible
to execute other instructions between the two steps as long as it does not compromise the handling of I/O,
but the order of operations is important for flag clearing.
Read: Anytime
Write: Has no meaning or effect
1
RWU
Receiver Wakeup Bit — Standby state
0 Normal operation.
1 RWU enables the wakeup function and inhibits further receiver interrupt requests. Normally, hardware wakes
the receiver by automatically clearing RWU.
0
SBK
Send Break Bit — Toggling SBK sends one break character (10 or 11 logic 0s, respectively 13 or 14 logics 0s
if BRK13 is set). Toggling implies clearing the SBK bit before the break character has finished transmitting. As
long as SBK is set, the transmitter continues to send complete break characters (10 or 11 bits, respectively 13
or 14 bits).
0 No break characters
1 Transmit break characters
Module Base + 0x_0004
76543210
R TDRE TC RDRF IDLE OR NF FE PF
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 13-6. SCI Status Register 1 (SCISR1)
Table 13-5. SCISR1 Field Descriptions
Field Description
7
TDRE
Transmit Data Register Empty Flag — TDRE is set when the transmit shift register receives a byte from the
SCI data register. When TDRE is 1, the transmit data register (SCIDRH/L) is empty and can receive a new value
to transmit.Clear TDRE by reading SCI status register 1 (SCISR1), with TDRE set and then writing to SCI data
register low (SCIDRL).
0 No byte transferred to transmit shift register
1 Byte transferred to transmit shift register; transmit data register empty
6
TC
Transmit Complete Flag — TC is set low when there is a transmission in progress or when a preamble or break
character is loaded. TC is set high when the TDRE flag is set and no data, preamble, or break character is being
transmitted.When TC is set, the TXD out signal becomes idle (logic 1). Clear TC by reading SCI status register
1 (SCISR1) with TC set and then writing to SCI data register low (SCIDRL). TC is cleared automatically when
data, preamble, or break is queued and ready to be sent. TC is cleared in the event of a simultaneous set and
clear of the TC flag (transmission not complete).
0 Transmission in progress
1 No transmission in progress
Table 13-4. SCICR2 Field Descriptions (continued)
Field Description
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 391
Rev 01.24
5
RDRF
Receive Data Register Full Flag — RDRF is set when the data in the receive shift register transfers to the SCI
data register. Clear RDRF by reading SCI status register 1 (SCISR1) with RDRF set and then reading SCI data
register low (SCIDRL).
0 Data not available in SCI data register
1 Received data available in SCI data register
4
IDLE
Idle Line Flag — IDLE is set when 10 consecutive logic 1s (if M=0) or 11 consecutive logic 1s (if M=1) appear
on the receiver input. Once the IDLE flag is cleared, a valid frame must again set the RDRF flag before an idle
condition can set the IDLE flag.Clear IDLE by reading SCI status register 1 (SCISR1) with IDLE set and then
reading SCI data register low (SCIDRL).
0 Receiver input is either active now or has never become active since the IDLE flag was last cleared
1 Receiver input has become idle
Note: When the receiver wakeup bit (RWU) is set, an idle line condition does not set the IDLE flag.
3
OR
Overrun Flag — OR is set when software fails to read the SCI data register before the receive shift register
receives the next frame. The OR bit is set immediately after the stop bit has been completely received for the
second frame. The data in the shift register is lost, but the data already in the SCI data registers is not affected.
Clear OR by reading SCI status register 1 (SCISR1) with OR set and then reading SCI data register low
(SCIDRL).
0 No overrun
1 Overrun
Note: OR flag may read back as set when RDRF flag is clear. This may happen if the following sequence of
events occurs:
1. After the first frame is received, read status register SCISR1 (returns RDRF set and OR flag clear);
2. Receive second frame without reading the first frame in the data register (the second frame is not
received and OR flag is set);
3. Read data register SCIDRL (returns first frame and clears RDRF flag in the status register);
4. Read status register SCISR1 (returns RDRF clear and OR set).
Event 3 may be at exactly the same time as event 2 or any time after. When this happens, a dummy
SCIDRL read following event 4 will be required to clear the OR flag if further frames are to be received.
2
NF
Noise Flag — NF is set when the SCI detects noise on the receiver input. NF bit is set during the same cycle as
the RDRF flag but does not get set in the case of an overrun. Clear NF by reading SCI status register 1(SCISR1),
and then reading SCI data register low (SCIDRL).
0 No noise
1 Noise
1
FE
Framing Error Flag — FE is set when a logic 0 is accepted as the stop bit. FE bit is set during the same cycle
as the RDRF flag but does not get set in the case of an overrun. FE inhibits further data reception until it is
cleared. Clear FE by reading SCI status register 1 (SCISR1) with FE set and then reading the SCI data register
low (SCIDRL).
0 No framing error
1 Framing error
0
PF
Parity Error Flag — PF is set when the parity enable bit (PE) is set and the parity of the received data does not
match the parity type bit (PT). PF bit is set during the same cycle as the RDRF flag but does not get set in the
case of an overrun. Clear PF by reading SCI status register 1 (SCISR1), and then reading SCI data register low
(SCIDRL).
0 No parity error
1 Parity error
Table 13-5. SCISR1 Field Descriptions (continued)
Field Description
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
392 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.3.2.5 SCI Status Register 2 (SCISR2)
Read: Anytime
Write: Anytime; writing accesses SCI status register 2; writing to any bits except TXDIR and BRK13
(SCISR2[1] & [2]) has no effect
Module Base + 0x_0005
76543210
R00000
BK13 TXDIR
RAF
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 13-7. SCI Status Register 2 (SCISR2)
Table 13-6. SCISR2 Field Descriptions
Field Description
2
BK13
Break Transmit Character Length — This bit determines whether the transmit break character is 10 or 11 bit
respectively 13 or 14 bits long. The detection of a framing error is not affected by this bit.
0 Break Character is 10 or 11 bit long
1 Break character is 13 or 14 bit long
1
TXDIR
Transmitter Pin Data Direction in Single-Wire Mode. — This bit determines whether the TXD pin is going to
be used as an input or output, in the Single-Wire mode of operation. This bit is only relevant in the Single-Wire
mode of operation.
0 TXD pin to be used as an input in Single-Wire mode
1 TXD pin to be used as an output in Single-Wire mode
0
RAF
Receiver Active Flag — RAF is set when the receiver detects a logic 0 during the RT1 time period of the start
bit search. RAF is cleared when the receiver detects an idle character.
0 No reception in progress
1 Reception in progress
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 393
Rev 01.24
13.3.2.6 SCI Data Registers (SCIDRH and SCIDRL)
Read: Anytime; reading accesses SCI receive data register
Write: Anytime; writing accesses SCI transmit data register; writing to R8 has no effect
NOTE
If the value of T8 is the same as in the previous transmission, T8 does not
have to be rewritten.The same value is transmitted until T8 is rewritten
In 8-bit data format, only SCI data register low (SCIDRL) needs to be
accessed.
When transmitting in 9-bit data format and using 8-bit write instructions,
write first to SCI data register high (SCIDRH), then SCIDRL.
Module Base + 0x_0006
76543210
RR8
T8
000000
W
Reset 0 0 0 00000
Module Base + 0x_0007
76543210
RR7R6R5R4R3R2R1R0
W T7 T6 T5 T4 T3 T2 T1 T0
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 13-8. SCI Data Registers (SCIDRH and SCIDRL)
Table 13-7. SCIDRH AND SCIDRL Field Descriptions
Field Description
7
R8
Received Bit 8 — R8 is the ninth data bit received when the SCI is configured for 9-bit data format (M = 1).
6
T8
Transmit Bit 8 — T8 is the ninth data bit transmitted when the SCI is configured for 9-bit data format (M = 1).
7–0
R[7:0]
T[7:0]
Received Bits — Received bits seven through zero for 9-bit or 8-bit data formats
Transmit Bits — Transmit bits seven through zero for 9-bit or 8-bit formats
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
394 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.4 Functional Description
This section provides a complete functional description of the SCI block, detailing the operation of the
design from the end user perspective in a number of subsections.
Figure 13-9 shows the structure of the SCI module. The SCI allows full duplex, asynchronous, NRZ serial
communication between the CPU and remote devices, including other CPUs. The SCI transmitter and
receiver operate independently, although they use the same baud rate generator. The CPU monitors the
status of the SCI, writes the data to be transmitted, and processes received data.
Figure 13-9. SCI Block Diagram
SCI DATA
RECEIVE
SHIFT REGISTER
SCI DATA
REGISTER
TRANSMIT
SHIFT REGISTER
REGISTER
BAUD RATE
GENERATOR
SBR12–SBR0
BUS
TRANSMIT
CONTROL
÷16
RECEIVE
AND WAKEUP
DATA FORMAT
CONTROL
CONTROL
T8
PF
FE
NF
RDRF
IDLE
TIE
OR
TCIE
TDRE
TC
R8
RAF
LOOPS
RWU
RE
PE
ILT
PT
WAKE
M
CLOCK
ILIE
RIE
RXD
RSRC
SBK
LOOPS
TE
RSRC
TXD
RDRF/OR IRQ
TDRE IRQ
IDLE IRQ
TC IRQ
IRQ
TO CPU
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 395
Rev 01.24
13.4.1 Data Format
The SCI uses the standard NRZ mark/space data format illustrated in Figure 13-10 below.
Figure 13-10. SCI Data Formats
Each data character is contained in a frame that includes a start bit, eight or nine data bits, and a stop bit.
Clearing the M bit in SCI control register 1 configures the SCI for 8-bit data characters.A frame with eight
data bits has a total of 10 bits. Setting the M bit configures the SCI for nine-bit data characters. A frame
with nine data bits has a total of 11 bits
When the SCI is configured for 9-bit data characters, the ninth data bit is the T8 bit in SCI data register
high (SCIDRH). It remains unchanged after transmission and can be used repeatedly without rewriting it.
A frame with nine data bits has a total of 11 bits.
Table 13-9. Example of 9-Bit Data Formats
Table 13-8. Example of 8-Bit Data Formats
Start
Bit
Data
Bits
Address
Bits
Parity
Bits
Stop
Bit
18 0 0 1
17 0 1 1
17 1
(1)
1. The address bit identifies the frame as an address character. See
Section 13.4.4.6, “Receiver Wakeup”.
01
Start
Bit
Data
Bits
Address
Bits
Parity
Bits
Stop
Bit
19 0 0 1
18 0 1 1
18 1
(1)
1. The address bit identifies the frame as an address character. See
Section 13.4.4.6, “Receiver Wakeup”.
01
BIT 5
START
BIT BIT 0 BIT 1
NEXT
STOP
BIT
START
BIT
9-BIT DATA FORMAT
BIT 2 BIT 3 BIT 4 BIT 6 BIT 7
PARITY
OR DATA
BIT
PARITY
OR DATA
BIT
BIT M IN SCICR1 SET
8-BIT DATA FORMAT
BIT M IN SCICR1 CLEAR
BIT 5BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 6 BIT 7 BIT 8 STOP
BIT
NEXT
START
BIT
START
BIT
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
396 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.4.2 Baud Rate Generation
A 13-bit modulus counter in the baud rate generator derives the baud rate for both the receiver and the
transmitter. The value from 0 to 8191 written to the SBR12–SBR0 bits determines the module clock
divisor. The SBR bits are in the SCI baud rate registers (SCIBDH and SCIBDL). The baud rate clock is
synchronized with the bus clock and drives the receiver. The baud rate clock divided by 16 drives the
transmitter. The receiver has an acquisition rate of 16 samples per bit time.
Baud rate generation is subject to one source of error:
Integer division of the module clock may not give the exact target frequency.
Table 13-10 lists some examples of achieving target baud rates with a module clock frequency of 25 MHz
SCI baud rate = SCI module clock / (16 * SCIBR[12:0])
Table 13-10. Baud Rates (Example: Module Clock = 25 MHz)
Bits
SBR[12-0]
Receiver
Clock (Hz)
Transmitter
Clock (Hz)
Target Baud
Rate
Error
(%)
41 609,756.1 38,109.8 38,400 .76
81 308,642.0 19,290.1 19,200 .47
163 153,374.2 9585.9 9600 .16
326 76,687.1 4792.9 4800 .15
651 38,402.5 2400.2 2400 .01
1302 19,201.2 1200.1 1200 .01
2604 9600.6 600.0 600 .00
5208 4800.0 300.0 300 .00
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 397
Rev 01.24
13.4.3 Transmitter
Figure 13-11. Transmitter Block Diagram
13.4.3.1 Transmitter Character Length
The SCI transmitter can accommodate either 8-bit or 9-bit data characters. The state of the M bit in SCI
control register 1 (SCICR1) determines the length of data characters. When transmitting 9-bit data, bit T8
in SCI data register high (SCIDRH) is the ninth bit (bit 8).
13.4.3.2 Character Transmission
To transmit data, the MCU writes the data bits to the SCI data registers (SCIDRH/SCIDRL), which in turn
are transferred to the transmitter shift register. The transmit shift register then shifts a frame out through
the Tx output signal, after it has prefaced them with a start bit and appended them with a stop bit. The SCI
data registers (SCIDRH and SCIDRL) are the write-only buffers between the internal data bus and the
transmit shift register.
The SCI also sets a flag, the transmit data register empty flag (TDRE), every time it transfers data from the
buffer (SCIDRH/L) to the transmitter shift register.The transmit driver routine may respond to this flag by
PE
PT
H876543210L
11-BIT TRANSMIT SHIFT REGISTER
STOP
START
T8
TDRE
TIE
TCIE
SBK
TC
PARITY
GENERATION
MSB
SCI DATA REGISTERS
LOAD FROM SCIDR
SHIFT ENABLE
PREAMBLE (ALL ONES)
BREAK (ALL 0s)
TRANSMITTER CONTROL
M
INTERNAL BUS
SBR12–SBR0
BAUD DIVIDER ÷ 16
TDRE INTERRUPT REQUEST
TC INTERRUPT REQUEST
BUS
LOOP
RSRC
CLOCK
TE
TO
CONTROL RXD
LOOPS
TXD
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
398 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
writing another byte to the Transmitter buffer (SCIDRH/SCIDRL), while the shift register is still shifting
out the first byte.
To initiate an SCI transmission:
1. Configure the SCI:
a) Select a baud rate. Write this value to the SCI baud registers (SCIBDH/L) to begin the baud
rate generator. Remember that the baud rate generator is disabled when the baud rate is zero.
Writing to the SCIBDH has no effect without also writing to SCIBDL.
b) Write to SCICR1 to configure word length, parity, and other configuration bits
(LOOPS,RSRC,M,WAKE,ILT,PE,PT).
c) Enable the transmitter, interrupts, receive, and wake up as required, by writing to the SCICR2
register bits (TIE,TCIE,RIE,ILIE,TE,RE,RWU,SBK). A preamble or idle character will now
be shifted out of the transmitter shift register.
2. Transmit Procedure for Each Byte:
a. Poll the TDRE flag by reading the SCISR1 or responding to the TDRE interrupt. Keep in mind
that the TDRE bit resets to one.
d) If the TDRE flag is set, write the data to be transmitted to SCIDRH/L, where the ninth bit is
written to the T8 bit in SCIDRH if the SCI is in 9-bit data format. A new transmission will not
result until the TDRE flag has been cleared.
3. Repeat step 2 for each subsequent transmission.
NOTE
The TDRE flag is set when the shift register is loaded with the next data to
be transmitted from SCIDRH/L, which happens, generally speaking, a little
over half-way through the stop bit of the previous frame. Specifically, this
transfer occurs 9/16ths of a bit time AFTER the start of the stop bit of the
previous frame.
Writing the TE bit from 0 to a 1 automatically loads the transmit shift register with a preamble of 10 logic
1s (if M = 0) or 11 logic 1s (if M = 1). After the preamble shifts out, control logic transfers the data from
the SCI data register into the transmit shift register. A logic 0 start bit automatically goes into the least
significant bit position of the transmit shift register. A logic 1 stop bit goes into the most significant bit
position.
Hardware supports odd or even parity. When parity is enabled, the most significant bit (msb) of the data
character is the parity bit.
The transmit data register empty flag, TDRE, in SCI status register 1 (SCISR1) becomes set when the SCI
data register transfers a byte to the transmit shift register. The TDRE flag indicates that the SCI data
register can accept new data from the internal data bus. If the transmit interrupt enable bit, TIE, in SCI
control register 2 (SCICR2) is also set, the TDRE flag generates a transmitter interrupt request.
When the transmit shift register is not transmitting a frame, the Tx output signal goes to the idle condition,
logic 1. If at any time software clears the TE bit in SCI control register 2 (SCICR2), the transmitter enable
signal goes low and the transmit signal goes idle.
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 399
Rev 01.24
If software clears TE while a transmission is in progress (TC = 0), the frame in the transmit shift register
continues to shift out. To avoid accidentally cutting off the last frame in a message, always wait for TDRE
to go high after the last frame before clearing TE.
To separate messages with preambles with minimum idle line time, use this sequence between messages:
1. Write the last byte of the first message to SCIDRH/L.
2. Wait for the TDRE flag to go high, indicating the transfer of the last frame to the transmit shift
register.
3. Queue a preamble by clearing and then setting the TE bit.
4. Write the first byte of the second message to SCIDRH/L.
13.4.3.3 Break Characters
Writing a logic 1 to the send break bit, SBK, in SCI control register 2 (SCICR2) loads the transmit shift
register with a break character. A break character contains all logic 0s and has no start, stop, or parity bit.
Break character length depends on the M bit in SCI control register 1 (SCICR1). As long as SBK is at
logic 1, transmitter logic continuously loads break characters into the transmit shift register. After software
clears the SBK bit, the shift register finishes transmitting the last break character and then transmits at least
one logic 1. The automatic logic 1 at the end of a break character guarantees the recognition of the start bit
of the next frame.
The SCI recognizes a break character when a start bit is followed by eight or nine logic 0 data bits and a
logic 0 where the stop bit should be. Receiving a break character has these effects on SCI registers:
• Sets the framing error flag, FE
• Sets the receive data register full flag, RDRF
• Clears the SCI data registers (SCIDRH/L)
• May set the overrun flag, OR, noise flag, NF, parity error flag, PE, or the receiver active flag, RAF
(see Section 13.3.2.4, “SCI Status Register 1 (SCISR1)” and Section 13.3.2.5, “SCI Status
Register 2 (SCISR2)”
13.4.3.4 Idle Characters
An idle character contains all logic 1s and has no start, stop, or parity bit. Idle character length depends on
the M bit in SCI control register 1 (SCICR1). The preamble is a synchronizing idle character that begins
the first transmission initiated after writing the TE bit from 0 to 1.
If the TE bit is cleared during a transmission, the Tx output signal becomes idle after completion of the
transmission in progress. Clearing and then setting the TE bit during a transmission queues an idle
character to be sent after the frame currently being transmitted.
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
400 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
NOTE
When queueing an idle character, return the TE bit to logic 1 before the stop
bit of the current frame shifts out through the Tx output signal. Setting TE
after the stop bit appears on Tx output signal causes data previously written
to the SCI data register to be lost. Toggle the TE bit for a queued idle
character while the TDRE flag is set and immediately before writing the
next byte to the SCI data register.
NOTE
If the TE bit is clear and the transmission is complete, the SCI is not the
master of the TXD pin
13.4.4 Receiver
Figure 13-12. SCI Receiver Block Diagram
13.4.4.1 Receiver Character Length
The SCI receiver can accommodate either 8-bit or 9-bit data characters. The state of the M bit in SCI
control register 1 (SCICR1) determines the length of data characters. When receiving 9-bit data, bit R8 in
SCI data register high (SCIDRH) is the ninth bit (bit 8).
ALL ONES
M
WAKE
ILT
PE
PT
RE
H876543210L
11-BIT RECEIVE SHIFT REGISTER
STOP
START
DATA
WAKEUP
PARITY
CHECKING
MSB
SCI DATA REGISTER
R8
RIE
ILIE
RWU
RDRF
OR
NF
FE
PE
INTERNAL
BUS
BUS
IDLE INTERRUPT REQUEST
RDRF/OR INTERRUPT REQUEST
SBR12–SBR0
BAUD DIVIDER
LOOP
RSRC
FROM TXD
CLOCK
IDLE
RAF
RECOVERY
CONTROL
LOGIC
LOOPS
RXD
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 401
Rev 01.24
13.4.4.2 Character Reception
During an SCI reception, the receive shift register shifts a frame in from the Rx input signal. The SCI data
register is the read-only buffer between the internal data bus and the receive shift register.
After a complete frame shifts into the receive shift register, the data portion of the frame transfers to the
SCI data register. The receive data register full flag, RDRF, in SCI status register 1 (SCISR1) becomes set,
indicating that the received byte can be read. If the receive interrupt enable bit, RIE, in SCI control
register 2 (SCICR2) is also set, the RDRF flag generates an RDRF interrupt request.
13.4.4.3 Data Sampling
The receiver samples the Rx input signal at the RT clock rate. The RT clock is an internal signal with a
frequency 16 times the baud rate. To adjust for baud rate mismatch, the RT clock (see Figure 13-13) is re-
synchronized:
• After every start bit
• After the receiver detects a data bit change from logic 1 to logic 0 (after the majority of data bit
samples at RT8, RT9, and RT10 returns a valid logic 1 and the majority of the next RT8, RT9, and
RT10 samples returns a valid logic 0)
To locate the start bit, data recovery logic does an asynchronous search for a logic 0 preceded by three
logic 1s.When the falling edge of a possible start bit occurs, the RT clock begins to count to 16.
Figure 13-13. Receiver Data Sampling
To verify the start bit and to detect noise, data recovery logic takes samples at RT3, RT5, and RT7.
Table 13-11 summarizes the results of the start bit verification samples.
Table 13-11. Start Bit Verification
RT3, RT5, and RT7 Samples Start Bit Verification Noise Flag
000 Yes 0
001 Yes 1
010 Yes 1
011 No 0
RESET RT CLOCK
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT2
RT3
RT4
RT5
RT8
RT7
RT6
RT11
RT10
RT9
RT15
RT14
RT13
RT12
RT16
RT1
RT2
RT3
RT4
SAMPLES
RT CLOCK
RT CLOCK COUNT
START BIT
Rx Input Signal
START BIT
QUALIFICATION
START BIT DATA
SAMPLING
111111110000000
LSB
VERIFICATION
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
402 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
If start bit verification is not successful, the RT clock is reset and a new search for a start bit begins.
To determine the value of a data bit and to detect noise, recovery logic takes samples at RT8, RT9, and
RT10. Table 13-12 summarizes the results of the data bit samples.
NOTE
The RT8, RT9, and RT10 samples do not affect start bit verification. If any
or all of the RT8, RT9, and RT10 start bit samples are logic 1s following a
successful start bit verification, the noise flag (NF) is set and the receiver
assumes that the bit is a start bit (logic 0).
To verify a stop bit and to detect noise, recovery logic takes samples at RT8, RT9, and RT10. Table 13-13
summarizes the results of the stop bit samples.
Table 13-13. Stop Bit Recovery
100 Yes 1
101 No 0
110 No 0
111 No 0
Table 13-12. Data Bit Recovery
RT8, RT9, and RT10 Samples Data Bit Determination Noise Flag
000 0 0
001 0 1
010 0 1
011 1 1
100 0 1
101 1 1
110 1 1
111 1 0
RT8, RT9, and RT10 Samples Framing Error Flag Noise Flag
000 1 0
001 1 1
010 1 1
011 0 1
100 1 1
101 0 1
110 0 1
111 0 0
Table 13-11. Start Bit Verification
RT3, RT5, and RT7 Samples Start Bit Verification Noise Flag
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 403
Rev 01.24
In Figure 13-14 the verification samples RT3 and RT5 determine that the first low detected was noise and
not the beginning of a start bit. The RT clock is reset and the start bit search begins again. The noise flag
is not set because the noise occurred before the start bit was found.
Figure 13-14. Start Bit Search Example 1
In Figure 13-15, verification sample at RT3 is high. The RT3 sample sets the noise flag. Although the
perceived bit time is misaligned, the data samples RT8, RT9, and RT10 are within the bit time and data
recovery is successful.
Figure 13-15. Start Bit Search Example 2
RESET RT CLOCK
RT1
RT1
RT1
RT1
RT2
RT3
RT4
RT5
RT1
RT1
RT2
RT3
RT4
RT7
RT6
RT5
RT10
RT9
RT8
RT14
RT13
RT12
RT11
RT15
RT16
RT1
RT2
RT3
SAMPLES
RT CLOCK
RT CLOCK COUNT
START BIT
Rx Input Signal
110111100000
LSB
0 0
RESET RT CLOCK
RT1
RT1
RT1
RT1
RT1
RT1
RT2
RT3
RT4
RT5
RT6
RT7
RT8
RT11
RT10
RT9
RT14
RT13
RT12
RT2
RT1
RT16
RT15
RT3
RT4
RT5
RT6
RT7
SAMPLES
RT CLOCK
RT CLOCK COUNT
ACTUAL START BIT
Rx Input Signal
1111110000
LSB
00
PERCEIVED START BIT
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
404 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
In Figure 13-16, a large burst of noise is perceived as the beginning of a start bit, although the test sample
at RT5 is high. The RT5 sample sets the noise flag. Although this is a worst-case misalignment of perceived
bit time, the data samples RT8, RT9, and RT10 are within the bit time and data recovery is successful.
Figure 13-16. Start Bit Search Example 3
Figure 13-17 shows the effect of noise early in the start bit time. Although this noise does not affect proper
synchronization with the start bit time, it does set the noise flag.
Figure 13-17. Start Bit Search Example 4
RESET RT CLOCK
RT1
RT1
RT1
RT1
RT2
RT3
RT4
RT5
RT6
RT7
RT8
RT9
RT10
RT13
RT12
RT11
RT16
RT15
RT14
RT4
RT3
RT2
RT1
RT5
RT6
RT7
RT8
RT9
SAMPLES
RT CLOCK
RT CLOCK COUNT
ACTUAL START BIT
Rx input Signal
101110000
LSB
0
PERCEIVED START BIT
RESET RT CLOCK
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT2
RT3
RT4
RT7
RT6
RT5
RT10
RT9
RT8
RT14
RT13
RT12
RT11
RT15
RT16
RT1
RT2
RT3
SAMPLES
RT CLOCK
RT CLOCK COUNT
PERCEIVED AND ACTUAL START BIT
Rx Input Signal
11111001
LSB
11 1 1
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 405
Rev 01.24
Figure 13-18 shows a burst of noise near the beginning of the start bit that resets the RT clock. The sample
after the reset is low but is not preceded by three high samples that would qualify as a falling edge.
Depending on the timing of the start bit search and on the data, the frame may be missed entirely or it may
set the framing error flag.
Figure 13-18. Start Bit Search Example 5
In Figure 13-19, a noise burst makes the majority of data samples RT8, RT9, and RT10 high. This sets the
noise flag but does not reset the RT clock. In start bits only, the RT8, RT9, and RT10 data samples are
ignored.
Figure 13-19. Start Bit Search Example 6
RESET RT CLOCK
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT2
RT3
RT4
RT7
RT6
RT5
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
SAMPLES
RT CLOCK
RT CLOCK COUNT
START BIT
Rx Input Signal
11111010
LSB
11 1 1 1 0000000 0
NO START BIT FOUND
RESET RT CLOCK
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT1
RT2
RT3
RT4
RT7
RT6
RT5
RT10
RT9
RT8
RT14
RT13
RT12
RT11
RT15
RT16
RT1
RT2
RT3
SAMPLES
RT CLOCK
RT CLOCK COUNT
START BIT
Rx Input Signal
11111000
LSB
11 1 1 0 110
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
406 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.4.4.4 Framing Errors
If the data recovery logic does not detect a logic 1 where the stop bit should be in an incoming frame, it
sets the framing error flag, FE, in SCI status register 1 (SCISR1). A break character also sets the FE flag
because a break character has no stop bit. The FE flag is set at the same time that the RDRF flag is set.
13.4.4.5 Baud Rate Tolerance
A transmitting device may be operating at a baud rate below or above the receiver baud rate. Accumulated
bit time misalignment can cause one of the three stop bit data samples (RT8, RT9, and RT10) to fall outside
the actual stop bit.A noise error will occur if the RT8, RT9, and RT10 samples are not all the same logical
values. A framing error will occur if the receiver clock is misaligned in such a way that the majority of the
RT8, RT9, and RT10 stop bit samples are a logic zero.
As the receiver samples an incoming frame, it re-synchronizes the RT clock on any valid falling edge
within the frame. Re synchronization within frames will correct a misalignment between transmitter bit
times and receiver bit times.
13.4.4.5.1 Slow Data Tolerance
Figure 13-20 shows how much a slow received frame can be misaligned without causing a noise error or
a framing error. The slow stop bit begins at RT8 instead of RT1 but arrives in time for the stop bit data
samples at RT8, RT9, and RT10.
Figure 13-20. Slow Data
Let’s take RTr as receiver RT clock and RTt as transmitter RT clock.
For an 8-bit data character, it takes the receiver 9 bit times x 16 RTr cycles +7 RTr cycles =151 RTr cycles
to start data sampling of the stop bit.
With the misaligned character shown in Figure 13-20, the receiver counts 151 RTr cycles at the point when
the count of the transmitting device is 9 bit times x 16 RTt cycles = 144 RTt cycles.
The maximum percent difference between the receiver count and the transmitter count of a slow 8-bit data
character with no errors is:
((151 – 144) / 151) x 100 = 4.63%
For a 9-bit data character, it takes the receiver 10 bit times x 16 RTr cycles + 7 RTr cycles = 167 RTr cycles
to start data sampling of the stop bit.
MSB STOP
RT1
RT2
RT3
RT4
RT5
RT6
RT7
RT8
RT9
RT10
RT11
RT12
RT13
RT14
RT15
RT16
DATA
SAMPLES
RECEIVER
RT CLOCK
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 407
Rev 01.24
With the misaligned character shown in Figure 13-20, the receiver counts 167 RTr cycles at the point when
the count of the transmitting device is 10 bit times x 16 RTt cycles = 160 RTt cycles.
The maximum percent difference between the receiver count and the transmitter count of a slow 9-bit
character with no errors is:
((167 – 160) / 167) X 100 = 4.19%
13.4.4.5.2 Fast Data Tolerance
Figure 13-21 shows how much a fast received frame can be misaligned. The fast stop bit ends at RT10
instead of RT16 but is still sampled at RT8, RT9, and RT10.
Figure 13-21. Fast Data
For an 8-bit data character, it takes the receiver 9 bit times x 16 RTr cycles + 10 RTr cycles = 154 RTr cycles
to finish data sampling of the stop bit.
With the misaligned character shown in Figure 13-21, the receiver counts 154 RTr cycles at the point when
the count of the transmitting device is 10 bit times x 16 RTt cycles = 160 RTt cycles.
The maximum percent difference between the receiver count and the transmitter count of a fast 8-bit
character with no errors is:
((160 – 154) / 160) x 100 = 3.75%
For a 9-bit data character, it takes the receiver 10 bit times x 16 RTr cycles + 10 RTr cycles = 170 RTr cycles
to finish data sampling of the stop bit.
With the misaligned character shown in Figure 13-21, the receiver counts 170 RTr cycles at the point when
the count of the transmitting device is 11 bit times x 16 RTt cycles = 176 RTt cycles.
The maximum percent difference between the receiver count and the transmitter count of a fast 9-bit
character with no errors is:
((176 – 170) / 176) x 100 = 3.40%
13.4.4.6 Receiver Wakeup
To enable the SCI to ignore transmissions intended only for other receivers in multiple-receiver systems,
the receiver can be put into a standby state. Setting the receiver wakeup bit, RWU, in SCI control register
2 (SCICR2) puts the receiver into standby state during which receiver interrupts are disabled.The SCI will
still load the receive data into the SCIDRH/L registers, but it will not set the RDRF flag.
IDLE OR NEXT FRAMESTOP
RT1
RT2
RT3
RT4
RT5
RT6
RT7
RT8
RT9
RT10
RT11
RT12
RT13
RT14
RT15
RT16
DATA
SAMPLES
RECEIVER
RT CLOCK
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
408 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The transmitting device can address messages to selected receivers by including addressing information in
the initial frame or frames of each message.
The WAKE bit in SCI control register 1 (SCICR1) determines how the SCI is brought out of the standby
state to process an incoming message. The WAKE bit enables either idle line wakeup or address mark
wakeup.
13.4.4.6.1 Idle Input Line Wakeup (WAKE = 0)
In this wakeup method, an idle condition on the Rx Input signal clears the RWU bit and wakes up the SCI.
The initial frame or frames of every message contain addressing information. All receivers evaluate the
addressing information, and receivers for which the message is addressed process the frames that follow.
Any receiver for which a message is not addressed can set its RWU bit and return to the standby state. The
RWU bit remains set and the receiver remains on standby until another idle character appears on the Rx
Input signal.
Idle line wakeup requires that messages be separated by at least one idle character and that no message
contains idle characters.
The idle character that wakes a receiver does not set the receiver idle bit, IDLE, or the receive data register
full flag, RDRF.
The idle line type bit, ILT, determines whether the receiver begins counting logic 1s as idle character bits
after the start bit or after the stop bit. ILT is in SCI control register 1 (SCICR1).
13.4.4.6.2 Address Mark Wakeup (WAKE = 1)
In this wakeup method, a logic 1 in the most significant bit (msb) position of a frame clears the RWU bit
and wakes up the SCI. The logic 1 in the msb position marks a frame as an address frame that contains
addressing information. All receivers evaluate the addressing information, and the receivers for which the
message is addressed process the frames that follow.Any receiver for which a message is not addressed can
set its RWU bit and return to the standby state. The RWU bit remains set and the receiver remains on
standby until another address frame appears on the Rx Input signal.
The logic 1 msb of an address frame clears the receiver’s RWU bit before the stop bit is received and sets
the RDRF flag.
Address mark wakeup allows messages to contain idle characters but requires that the msb be reserved for
use in address frames.{sci_wake}
NOTE
With the WAKE bit clear, setting the RWU bit after the Rx Input signal has
been idle can cause the receiver to wake up immediately.
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 409
Rev 01.24
13.4.5 Single-Wire Operation
Normally, the SCI uses two pins for transmitting and receiving. In single-wire operation, the RXD pin is
disconnected from the SCI. The SCI uses the TXD pin for both receiving and transmitting.
Figure 13-22. Single-Wire Operation (LOOPS = 1, RSRC = 1)
Enable single-wire operation by setting the LOOPS bit and the receiver source bit, RSRC, in SCI control
register 1 (SCICR1). Setting the LOOPS bit disables the path from the Rx Input signal to the receiver.
Setting the RSRC bit connects the receiver input to the output of the TXD pin driver. Both the transmitter
and receiver must be enabled (TE = 1 and RE = 1).The TXDIR bit (SCISR2[1]) determines whether the
TXD pin is going to be used as an input (TXDIR = 0) or an output (TXDIR = 1) in this mode of operation.
13.4.6 Loop Operation
In loop operation the transmitter output goes to the receiver input. The Rx Input signal is disconnected
from the SCI
.
Figure 13-23. Loop Operation (LOOPS = 1, RSRC = 0)
Enable loop operation by setting the LOOPS bit and clearing the RSRC bit in SCI control register 1
(SCICR1). Setting the LOOPS bit disables the path from the Rx Input signal to the receiver. Clearing the
RSRC bit connects the transmitter output to the receiver input. Both the transmitter and receiver must be
enabled (TE = 1 and RE = 1).
13.5 Initialization Information
13.5.1 Reset Initialization
The reset state of each individual bit is listed in Section 13.3, “Memory Map and Registers” which details
the registers and their bit fields. All special functions or modes which are initialized during or just
following reset are described within this section.
RXD
TRANSMITTER
RECEIVER
Tx OUTPUT SIGNAL
Tx INPUT SIGNAL
RXD
TRANSMITTER
RECEIVER
Tx OUTPUT SIGNAL
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
410 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
13.5.2 Interrupt Operation
13.5.2.1 System Level Interrupt Sources
There are five interrupt sources that can generate an SCI interrupt in to the CPU. They are listed in
Table 13-14.
Table 13-14. SCI Interrupt Source
Interrupt Source Flag Local Enable
Transmitter TDRE TIE
Transmitter TC TCIE
Receiver RDRF RIE
OR
Receiver IDLE ILIE
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 411
Rev 01.24
13.5.2.2 Interrupt Descriptions
The SCI only originates interrupt requests. The following is a description of how the SCI makes a request
and how the MCU should acknowledge that request. The interrupt vector offset and interrupt number are
chip dependent. The SCI only has a single interrupt line (SCI Interrupt Signal, active high operation) and
all the following interrupts, when generated, are ORed together and issued through that port.
13.5.2.2.1 TDRE Description
The TDRE interrupt is set high by the SCI when the transmit shift register receives a byte from the SCI
data register. A TDRE interrupt indicates that the transmit data register (SCIDRH/L) is empty and that a
new byte can be written to the SCIDRH/L for transmission.Clear TDRE by reading SCI status register 1
with TDRE set and then writing to SCI data register low (SCIDRL).
13.5.2.2.2 TC Description
The TC interrupt is set by the SCI when a transmission has been completed.A TC interrupt indicates that
there is no transmission in progress. TC is set high when the TDRE flag is set and no data, preamble, or
break character is being transmitted. When TC is set, the TXD pin becomes idle (logic 1). Clear TC by
reading SCI status register 1 (SCISR1) with TC set and then writing to SCI data register low (SCIDRL).TC
is cleared automatically when data, preamble, or break is queued and ready to be sent.
13.5.2.2.3 RDRF Description
The RDRF interrupt is set when the data in the receive shift register transfers to the SCI data register. A
RDRF interrupt indicates that the received data has been transferred to the SCI data register and that the
byte can now be read by the MCU. The RDRF interrupt is cleared by reading the SCI status register one
(SCISR1) and then reading SCI data register low (SCIDRL).
13.5.2.2.4 OR Description
The OR interrupt is set when software fails to read the SCI data register before the receive shift register
receives the next frame. The newly acquired data in the shift register will be lost in this case, but the data
already in the SCI data registers is not affected. The OR interrupt is cleared by reading the SCI status
register one (SCISR1) and then reading SCI data register low (SCIDRL).
13.5.2.3 IDLE Description
The IDLE interrupt is set when 10 consecutive logic 1s (if M = 0) or 11 consecutive logic 1s (if M = 1)
appear on the receiver input. Once the IDLE is cleared, a valid frame must again set the RDRF flag before
an idle condition can set the IDLE flag. Clear IDLE by reading SCI status register 1 (SCISR1) with IDLE
set and then reading SCI data register low (SCIDRL).
13.5.3 Recovery from Wait Mode
The SCI interrupt request can be used to bring the CPU out of wait mode.
Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
412 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 413
Rev 01.24
Chapter 14
Serial Peripheral Interface (SPIV3) Block Description
14.1 Introduction
The SPI module allows a duplex, synchronous, serial communication between the MCU and peripheral
devices. Software can poll the SPI status flags or the SPI operation can be interrupt driven.
14.1.1 Features
The SPIV3 includes these distinctive features:
• Master mode and slave mode
• Bidirectional mode
• Slave select output
• Mode fault error flag with CPU interrupt capability
• Double-buffered data register
• Serial clock with programmable polarity and phase
• Control of SPI operation during wait mode
14.1.2 Modes of Operation
The SPI functions in three modes, run, wait, and stop.
• Run Mode
This is the basic mode of operation.
• Wait Mode
SPI operation in wait mode is a configurable low power mode, controlled by the SPISWAI bit
located in the SPICR2 register. In wait mode, if the SPISWAI bit is clear, the SPI operates like in
Run Mode. If the SPISWAI bit is set, the SPI goes into a power conservative state, with the SPI
clock generation turned off. If the SPI is configured as a master, any transmission in progress stops,
but is resumed after CPU goes into Run Mode. If the SPI is configured as a slave, reception and
transmission of a byte continues, so that the slave stays synchronized to the master.
• Stop Mode
The SPI is inactive in stop mode for reduced power consumption. If the SPI is configured as a
master, any transmission in progress stops, but is resumed after CPU goes into run mode. If the SPI
is configured as a slave, reception and transmission of a byte continues, so that the slave stays
synchronized to the master.
This is a high level description only, detailed descriptions of operating modes are contained in
Section 14.4, “Functional Description.”
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
414 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
14.1.3 Block Diagram
Figure 14-1 gives an overview on the SPI architecture. The main parts of the SPI are status, control, and
data registers, shifter logic, baud rate generator, master/slave control logic, and port control logic.
Figure 14-1. SPI Block Diagram
14.2 External Signal Description
This section lists the name and description of all ports including inputs and outputs that do, or may, connect
off chip. The SPIV3 module has a total of four external pins.
14.2.1 MOSI — Master Out/Slave In Pin
This pin is used to transmit data out of the SPI module when it is configured as a master and receive data
when it is configured as slave.
SPI Control Register 1
SPI Control Register 2
SPI Baud Rate Register
SPI Status Register
SPI Data Register
Shifter
Port
Control
Logic
MOSI
SCK
Interrupt Control
SPI
MSB LSB
LSBFE=1 LSBFE=0
LSBFE=0 LSBFE=1
data in
LSBFE=1
LSBFE=0
data out
8
8
Baud Rate Generator
Prescaler
Bus Clock
Counter
Clock Select
SPPR 33
SPR
Baud Rate
Phase +
Polarity
Control
Master
Slave
SCK in
SCK out
Master Baud Rate
Slave Baud Rate
Phase +
Polarity
Control
Control
Control CPOL CPHA
2
BIDIROE
SPC0
2
MODFSPIF SPTEF
SPI
Request
Interrupt
SS
Shift
Clock
Sample
Clock
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 415
Rev 01.24
14.2.2 MISO — Master In/Slave Out Pin
This pin is used to transmit data out of the SPI module when it is configured as a slave and receive data
when it is configured as master.
14.2.3 SS — Slave Select Pin
This pin is used to output the select signal from the SPI module to another peripheral with which a data
transfer is to take place when its configured as a master and its used as an input to receive the slave select
signal when the SPI is configured as slave.
14.2.4 SCK — Serial Clock Pin
This pin is used to output the clock with respect to which the SPI transfers data or receive clock in case of
slave.
14.3 Memory Map and Register Definition
This section provides a detailed description of address space and registers used by the SPI.
The memory map for the SPIV3 is given below in Table 14-1. The address listed for each register is the
sum of a base address and an address offset. The base address is defined at the SoC level and the address
offset is defined at the module level. Reads from the reserved bits return zeros and writes to the reserved
bits have no effect.
14.3.1 Module Memory Map
Table 14-1. SPIV3 Memory Map
Address Use Access
0x0000 SPI Control Register 1 (SPICR1) R/W
0x0001 SPI Control Register 2 (SPICR2) R/W(1)
1. Certain bits are non-writable.
0x0002 SPI Baud Rate Register (SPIBR) R/W1
0x0003 SPI Status Register (SPISR) R(2)
2. Writes to this register are ignored.
0x0004 Reserved — 2,(3)
3. Reading from this register returns all zeros.
0x0005 SPI Data Register (SPIDR) R/W
0x0006 Reserved — 2,3
0x0007 Reserved — 2,3
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
416 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
14.3.2 Register Descriptions
This section consists of register descriptions in address order. Each description includes a standard register
diagram with an associated figure number. Details of register bit and field function follow the register
diagrams, in bit order.
14.3.2.1 SPI Control Register 1 (SPICR1)
Read: anytime
Write: anytime
Name 7 6 5 4 3 2 1 0
0x0000
SPICR1
RSPIE SPE SPTIE MSTR CPOL CPHA SSOE LSBFE
W
0x0001
SPICR2
R0 0 0 MODFEN BIDIROE 0SPISWAI SPC0
W
0x0002
SPIBR
R0 SPPR2 SPPR1 SPPR0 0SPR2 SPR1 SPR0
W
0x0003
SPISR
R SPIF 0 SPTEF MODF 0 0 0 0
W
0x0004
Reserved
R
W
0x0005
SPIDR
RBit 7 6 5 4 3 2 2 Bit 0
W
0x0006
Reserved
R
W
0x0007
Reserved
R
W
= Unimplemented or Reserved
Figure 14-2. SPI Register Summary
Module Base 0x0000
76543210
RSPIE SPE SPTIE MSTR CPOL CPHA SSOE LSBFE
W
Reset 0 0 0 00100
Figure 14-3. SPI Control Register 1 (SPICR1)
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 417
Rev 01.24
Table 14-2. SPICR1 Field Descriptions
Field Description
7
SPIE
SPI Interrupt Enable Bit — This bit enables SPI interrupt requests, if SPIF or MODF status flag is set.
0 SPI interrupts disabled.
1 SPI interrupts enabled.
6
SPE
SPI System Enable Bit — This bit enables the SPI system and dedicates the SPI port pins to SPI system
functions. If SPE is cleared, SPI is disabled and forced into idle state, status bits in SPISR register are reset.
0 SPI disabled (lower power consumption).
1 SPI enabled, port pins are dedicated to SPI functions.
5
SPTIE
SPI Transmit Interrupt Enable — This bit enables SPI interrupt requests, if SPTEF flag is set.
0 SPTEF interrupt disabled.
1 SPTEF interrupt enabled.
4
MSTR
SPI Master/Slave Mode Select Bit — This bit selects, if the SPI operates in master or slave mode. Switching
the SPI from master to slave or vice versa forces the SPI system into idle state.
0 SPI is in slave mode
1 SPI is in master mode
3
CPOL
SPI Clock Polarity Bit — This bit selects an inverted or non-inverted SPI clock. To transmit data between SPI
modules, the SPI modules must have identical CPOL values. In master mode, a change of this bit will abort a
transmission in progress and force the SPI system into idle state.
0 Active-high clocks selected. In idle state SCK is low.
1 Active-low clocks selected. In idle state SCK is high.
2
CPHA
SPI Clock Phase Bit — This bit is used to select the SPI clock format. In master mode, a change of this bit will
abort a transmission in progress and force the SPI system into idle state.
0 Sampling of data occurs at odd edges (1,3,5,...,15) of the SCK clock
1 Sampling of data occurs at even edges (2,4,6,...,16) of the SCK clock
1
SSOE
Slave Select Output Enable — The SS output feature is enabled only in master mode, if MODFEN is set, by
asserting the SSOE as shown in Table 14-3. In master mode, a change of this bit will abort a transmission in
progress and force the SPI system into idle state.
0
LSBFE
LSB-First Enable — This bit does not affect the position of the MSB and LSB in the data register. Reads and
writes of the data register always have the MSB in bit 7. In master mode, a change of this bit will abort a
transmission in progress and force the SPI system into idle state.
0 Data is transferred most significant bit first.
1 Data is transferred least significant bit first.
Table 14-3. SS Input / Output Selection
MODFEN SSOE Master Mode Slave Mode
00 SS not used by SPI SS input
01 SS not used by SPI SS input
10
SS input with MODF feature SS input
11 SS is slave select output SS input
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
418 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
14.3.2.2 SPI Control Register 2 (SPICR2)
Read: anytime
Write: anytime; writes to the reserved bits have no effect
Module Base 0x0001
76543210
R000
MODFEN BIDIROE
0
SPISWAI SPC0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 14-4. SPI Control Register 2 (SPICR2)
Table 14-4. SPICR2 Field Descriptions
Field Description
4
MODFEN
Mode Fault Enable Bit — This bit allows the MODF failure being detected. If the SPI is in master mode and
MODFEN is cleared, then the SS port pin is not used by the SPI. In slave mode, the SS is available only as an
input regardless of the value of MODFEN. For an overview on the impact of the MODFEN bit on the SS port pin
configuration refer to Table 14-3. In master mode, a change of this bit will abort a transmission in progress and
force the SPI system into idle state.
0SS port pin is not used by the SPI
1SS port pin with MODF feature
3
BIDIROE
Output Enable in the Bidirectional Mode of Operation — This bit controls the MOSI and MISO output buffer
of the SPI, when in bidirectional mode of operation (SPC0 is set). In master mode this bit controls the output
buffer of the MOSI port, in slave mode it controls the output buffer of the MISO port. In master mode, with SPC0
set, a change of this bit will abort a transmission in progress and force the SPI into idle state.
0 Output buffer disabled
1 Output buffer enabled
1
SPISWAI
SPI Stop in Wait Mode Bit — This bit is used for power conservation while in wait mode.
0 SPI clock operates normally in wait mode
1 Stop SPI clock generation when in wait mode
0
SPC0
Serial Pin Control Bit 0 — This bit enables bidirectional pin configurations as shown in Table 14-5. In master
mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state
Table 14-5. Bidirectional Pin Configurations
Pin Mode SPC0 BIDIROE MISO MOSI
Master Mode of Operation
Normal 0 X Master In Master Out
Bidirectional 1 0 MISO not used by SPI Master In
1 Master I/O
Slave Mode of Operation
Normal 0 X Slave Out Slave In
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 419
Rev 01.24
14.3.2.3 SPI Baud Rate Register (SPIBR)
Read: anytime
Write: anytime; writes to the reserved bits have no effect
The baud rate divisor equation is as follows:
The baud rate can be calculated with the following equation:
Bidirectional 1 0 Slave In MOSI not used by SPI
1 Slave I/O
Module Base 0x0002
76543210
R0
SPPR2 SPPR1 SPPR0
0
SPR2 SPR1 SPR0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 14-5. SPI Baud Rate Register (SPIBR)
Table 14-6. SPIBR Field Descriptions
Field Description
6:4
SPPR[2:0]
SPI Baud Rate Preselection Bits — These bits specify the SPI baud rates as shown in Table 14-7. In master
mode, a change of these bits will abort a transmission in progress and force the SPI system into idle state.
2:0
SPR[2:0}
SPI Baud Rate Selection Bits — These bits specify the SPI baud rates as shown in Table 14-7. In master mode,
a change of these bits will abort a transmission in progress and force the SPI system into idle state.
Table 14-5. Bidirectional Pin Configurations (continued)
Pin Mode SPC0 BIDIROE MISO MOSI
BaudRateDivisor SPPR 1+()2•SPR 1+()
=
Baud Rate BusClock BaudRateDivisor⁄=
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
420 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 14-7. Example SPI Baud Rate Selection (25 MHz Bus Clock)
SPPR2 SPPR1 SPPR0 SPR2 SPR1 SPR0 Baud Rate
Divisor Baud Rate
000000212.5 MHz
00000146.25 MHz
00001083.125 MHz
000011161.5625 MHz
00010032781.25 kHz
00010164390.63 kHz
000110128195.31 kHz
00011125697.66 kHz
00100046.25 MHz
00100183.125 MHz
001010161.5625 MHz
00101132781.25 kHz
00110064390.63 kHz
001101128195.31 kHz
00111025697.66 kHz
00111151248.83 kHz
01000064.16667 MHz
010001122.08333 MHz
010010241.04167 MHz
01001148520.83 kHz
01010096260.42 kHz
010101192130.21 kHz
01011038465.10 kHz
01011176832.55 kHz
01100083.125 MHz
011001161.5625 MHz
01101032781.25 kHz
01101164390.63 kHz
011100128195.31 kHz
01110125697.66 kHz
01111051248.83 kHz
0111111024 24.41 kHz
100000102.5 MHz
100001201.25 MHz
10001040625 kHz
10001180312.5 kHz
100100160156.25 kHz
10010132078.13 kHz
10011064039.06 kHz
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 421
Rev 01.24
NOTE
In slave mode of SPI S-clock speed DIV2 is not supported.
1001111280 19.53 kHz
101000122.08333 MHz
101001241.04167 MHz
10101048520.83 kHz
10101196260.42 kHz
101100192130.21 kHz
10110138465.10 kHz
10111076832.55 kHz
1011111536 16.28 kHz
110000141.78571 MHz
11000128892.86 kHz
11001056446.43 kHz
110011112223.21 kHz
110100224111.61 kHz
11010144855.80 kHz
11011089627.90 kHz
1101111792 13.95 kHz
111000161.5625 MHz
11100132781.25 kHz
11101064390.63 kHz
111011128195.31 kHz
11110025697.66 kHz
11110151248.83 kHz
1111101024 24.41 kHz
1111112048 12.21 kHz
Table 14-7. Example SPI Baud Rate Selection (25 MHz Bus Clock) (continued)
SPPR2 SPPR1 SPPR0 SPR2 SPR1 SPR0 Baud Rate
Divisor Baud Rate
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
422 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
14.3.2.4 SPI Status Register (SPISR)
Read: anytime
Write: has no effect
14.3.2.5 SPI Data Register (SPIDR)
Read: anytime; normally read only after SPIF is set
Module Base 0x0003
76543210
R SPIF 0 SPTEF MODF 0000
W
Reset 0 0 1 00000
= Unimplemented or Reserved
Figure 14-6. SPI Status Register (SPISR)
Table 14-8. SPISR Field Descriptions
Field Description
7
SPIF
SPIF Interrupt Flag — This bit is set after a received data byte has been transferred into the SPI Data Register.
This bit is cleared by reading the SPISR register (with SPIF set) followed by a read access to the SPI Data
Register.
0 Transfer not yet complete
1 New data copied to SPIDR
5
SPTEF
SPI Transmit Empty Interrupt Flag — If set, this bit indicates that the transmit data register is empty. To clear
this bit and place data into the transmit data register, SPISR has to be read with SPTEF = 1, followed by a write
to SPIDR. Any write to the SPI Data Register without reading SPTEF = 1, is effectively ignored.
0 SPI Data register not empty
1 SPI Data register empty
4
MODF
Mode Fault Flag — This bit is set if the SS input becomes low while the SPI is configured as a master and mode
fault detection is enabled, MODFEN bit of SPICR2 register is set. Refer to MODFEN bit description in
Section 14.3.2.2, “SPI Control Register 2 (SPICR2).”The flag is cleared automatically by a read of the SPI Status
Register (with MODF set) followed by a write to the SPI Control Register 1.
0 Mode fault has not occurred.
1 Mode fault has occurred.
Module Base 0x0005
76543210
R
Bit 7 6 5 4322Bit 0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 14-7. SPI Data Register (SPIDR)
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 423
Rev 01.24
Write: anytime
The SPI Data Register is both the input and output register for SPI data. A write to this register allows a
data byte to be queued and transmitted. For a SPI configured as a master, a queued data byte is transmitted
immediately after the previous transmission has completed. The SPI Transmitter Empty Flag SPTEF in
the SPISR register indicates when the SPI Data Register is ready to accept new data.
Reading the data can occur anytime from after the SPIF is set to before the end of the next transfer. If the
SPIF is not serviced by the end of the successive transfers, those data bytes are lost and the data within the
SPIDR retains the first byte until SPIF is serviced.
14.4 Functional Description
The SPI module allows a duplex, synchronous, serial communication between the MCU and peripheral
devices. Software can poll the SPI status flags or SPI operation can be interrupt driven.
The SPI system is enabled by setting the SPI enable (SPE) bit in SPI Control Register 1. While SPE bit is
set, the four associated SPI port pins are dedicated to the SPI function as:
• Slave select (SS)
• Serial clock (SCK)
• Master out/slave in (MOSI)
• Master in/slave out (MISO)
The main element of the SPI system is the SPI Data Register. The 8-bit data register in the master and the
8-bit data register in the slave are linked by the MOSI and MISO pins to form a distributed 16-bit register.
When a data transfer operation is performed, this 16-bit register is serially shifted eight bit positions by the
S-clock from the master, so data is exchanged between the master and the slave. Data written to the master
SPI Data Register becomes the output data for the slave, and data read from the master SPI Data Register
after a transfer operation is the input data from the slave.
A read of SPISR with SPTEF = 1 followed by a write to SPIDR puts data into the transmit data register.
When a transfer is complete, received data is moved into the receive data register. Data may be read from
this double-buffered system any time before the next transfer has completed. This 8-bit data register acts
as the SPI receive data register for reads and as the SPI transmit data register for writes. A single SPI
register address is used for reading data from the read data buffer and for writing data to the transmit data
register.
The clock phase control bit (CPHA) and a clock polarity control bit (CPOL) in the SPI Control Register 1
(SPICR1) select one of four possible clock formats to be used by the SPI system. The CPOL bit simply
selects a non-inverted or inverted clock. The CPHA bit is used to accommodate two fundamentally
different protocols by sampling data on odd numbered SCK edges or on even numbered SCK edges (see
Section 14.4.3, “Transmission Formats”).
The SPI can be configured to operate as a master or as a slave. When the MSTR bit in SPI Control
Register1 is set, master mode is selected, when the MSTR bit is clear, slave mode is selected.
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
424 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
14.4.1 Master Mode
The SPI operates in master mode when the MSTR bit is set. Only a master SPI module can initiate
transmissions. A transmission begins by writing to the master SPI Data Register. If the shift register is
empty, the byte immediately transfers to the shift register. The byte begins shifting out on the MOSI pin
under the control of the serial clock.
• S-clock
The SPR2, SPR1, and SPR0 baud rate selection bits in conjunction with the SPPR2, SPPR1, and
SPPR0 baud rate preselection bits in the SPI Baud Rate register control the baud rate generator and
determine the speed of the transmission. The SCK pin is the SPI clock output. Through the SCK
pin, the baud rate generator of the master controls the shift register of the slave peripheral.
• MOSI and MISO Pins
In master mode, the function of the serial data output pin (MOSI) and the serial data input pin
(MISO) is determined by the SPC0 and BIDIROE control bits.
•SS Pin
If MODFEN and SSOE bit are set, the SS pin is configured as slave select output. The SS output
becomes low during each transmission and is high when the SPI is in idle state.
If MODFEN is set and SSOE is cleared, the SS pin is configured as input for detecting mode fault
error. If the SS input becomes low this indicates a mode fault error where another master tries to
drive the MOSI and SCK lines. In this case, the SPI immediately switches to slave mode, by
clearing the MSTR bit and also disables the slave output buffer MISO (or SISO in bidirectional
mode). So the result is that all outputs are disabled and SCK, MOSI and MISO are inputs. If a
transmission is in progress when the mode fault occurs, the transmission is aborted and the SPI is
forced into idle state.
This mode fault error also sets the mode fault (MODF) flag in the SPI Status Register (SPISR). If the SPI
interrupt enable bit (SPIE) is set when the MODF flag gets set, then an SPI interrupt sequence is also
requested.
When a write to the SPI Data Register in the master occurs, there is a half SCK-cycle delay. After the delay,
SCK is started within the master. The rest of the transfer operation differs slightly, depending on the clock
format specified by the SPI clock phase bit, CPHA, in SPI Control Register 1 (see Section 14.4.3,
“Transmission Formats”).
NOTE
A change of the bits CPOL, CPHA, SSOE, LSBFE, MODFEN, SPC0,
BIDIROE with SPC0 set, SPPR2–SPPR0 and SPR2–SPR0 in master mode
will abort a transmission in progress and force the SPI into idle state. The
remote slave cannot detect this, therefore the master has to ensure that the
remote slave is set back to idle state.
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 425
Rev 01.24
14.4.2 Slave Mode
The SPI operates in slave mode when the MSTR bit in SPI Control Register1 is clear.
• SCK Clock
In slave mode, SCK is the SPI clock input from the master.
• MISO and MOSI Pins
In slave mode, the function of the serial data output pin (MISO) and serial data input pin (MOSI)
is determined by the SPC0 bit and BIDIROE bit in SPI Control Register 2.
•SS Pin
The SS pin is the slave select input. Before a data transmission occurs, the SS pin of the slave SPI
must be low. SS must remain low until the transmission is complete. If SS goes high, the SPI is
forced into idle state.
The SS input also controls the serial data output pin, if SS is high (not selected), the serial data
output pin is high impedance, and, if SS is low the first bit in the SPI Data Register is driven out of
the serial data output pin. Also, if the slave is not selected (SS is high), then the SCK input is
ignored and no internal shifting of the SPI shift register takes place.
Although the SPI is capable of duplex operation, some SPI peripherals are capable of only receiving SPI
data in a slave mode. For these simpler devices, there is no serial data out pin.
NOTE
When peripherals with duplex capability are used, take care not to
simultaneously enable two receivers whose serial outputs drive the same
system slave’s serial data output line.
As long as no more than one slave device drives the system slave’s serial data output line, it is possible for
several slaves to receive the same transmission from a master, although the master would not receive return
information from all of the receiving slaves.
If the CPHA bit in SPI Control Register 1 is clear, odd numbered edges on the SCK input cause the data
at the serial data input pin to be latched. Even numbered edges cause the value previously latched from the
serial data input pin to shift into the LSB or MSB of the SPI shift register, depending on the LSBFE bit.
If the CPHA bit is set, even numbered edges on the SCK input cause the data at the serial data input pin to
be latched. Odd numbered edges cause the value previously latched from the serial data input pin to shift
into the LSB or MSB of the SPI shift register, depending on the LSBFE bit.
When CPHA is set, the first edge is used to get the first data bit onto the serial data output pin. When CPHA
is clear and the SS input is low (slave selected), the first bit of the SPI data is driven out of the serial data
output pin. After the eighth shift, the transfer is considered complete and the received data is transferred
into the SPI Data Register. To indicate transfer is complete, the SPIF flag in the SPI Status Register is set.
NOTE
A change of the bits CPOL, CPHA, SSOE, LSBFE, MODFEN, SPC0 and
BIDIROE with SPC0 set in slave mode will corrupt a transmission in
progress and has to be avoided.
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
426 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
14.4.3 Transmission Formats
During an SPI transmission, data is transmitted (shifted out serially) and received (shifted in serially)
simultaneously. The serial clock (SCK) synchronizes shifting and sampling of the information on the two
serial data lines. A slave select line allows selection of an individual slave SPI device, slave devices that
are not selected do not interfere with SPI bus activities. Optionally, on a master SPI device, the slave select
line can be used to indicate multiple-master bus contention.
Figure 14-8. Master/Slave Transfer Block Diagram
14.4.3.1 Clock Phase and Polarity Controls
Using two bits in the SPI Control Register1, software selects one of four combinations of serial clock phase
and polarity.
The CPOL clock polarity control bit specifies an active high or low clock and has no significant effect on
the transmission format.
The CPHA clock phase control bit selects one of two fundamentally different transmission formats.
Clock phase and polarity should be identical for the master SPI device and the communicating slave
device. In some cases, the phase and polarity are changed between transmissions to allow a master device
to communicate with peripheral slaves having different requirements.
14.4.3.2 CPHA = 0 Transfer Format
The first edge on the SCK line is used to clock the first data bit of the slave into the master and the first
data bit of the master into the slave. In some peripherals, the first bit of the slave’s data is available at the
slave’s data out pin as soon as the slave is selected. In this format, the first SCK edge is issued a half cycle
after SS has become low.
A half SCK cycle later, the second edge appears on the SCK line. When this second edge occurs, the value
previously latched from the serial data input pin is shifted into the LSB or MSB of the shift register,
depending on LSBFE bit.
After this second edge, the next bit of the SPI master data is transmitted out of the serial data output pin of
the master to the serial input pin on the slave. This process continues for a total of 16 edges on the SCK
line, with data being latched on odd numbered edges and shifted on even numbered edges.
SHIFT REGISTER
SHIFT REGISTER
BAUD RATE
GENERATOR
MASTER SPI SLAVE SPI
MOSI MOSI
MISO MISO
SCK SCK
SS SS
VDD
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 427
Rev 01.24
Data reception is double buffered. Data is shifted serially into the SPI shift register during the transfer and
is transferred to the parallel SPI Data Register after the last bit is shifted in.
After the 16th (last) SCK edge:
• Data that was previously in the master SPI Data Register should now be in the slave data register
and the data that was in the slave data register should be in the master.
• The SPIF flag in the SPI Status Register is set indicating that the transfer is complete.
Figure 14-9 is a timing diagram of an SPI transfer where CPHA = 0. SCK waveforms are shown for
CPOL = 0 and CPOL = 1. The diagram may be interpreted as a master or slave timing diagram because
the SCK, MISO, and MOSI pins are connected directly between the master and the slave. The MISO signal
is the output from the slave and the MOSI signal is the output from the master. The SS pin of the master
must be either high or reconfigured as a general-purpose output not affecting the SPI.
Figure 14-9. SPI Clock Format 0 (CPHA = 0)
In slave mode, if the SS line is not deasserted between the successive transmissions then the content of the
SPI Data Register is not transmitted, instead the last received byte is transmitted. If the SS line is deasserted
for at least minimum idle time (half SCK cycle) between successive transmissions then the content of the
SPI Data Register is transmitted.
tL
Begin End
SCK (CPOL = 0)
SAMPLE I
CHANGE O
SEL SS (O)
Transfer
SCK (CPOL = 1)
MSB first (LSBFE = 0):
LSB first (LSBFE = 1):
MSB
LSB
LSB
MSB
Bit 5
Bit 2
Bit 6
Bit 1
Bit 4
Bit 3
Bit 3
Bit 4
Bit 2
Bit 5
Bit 1
Bit 6
CHANGE O
SEL SS (I)
MOSI pin
MISO pin
Master only
MOSI/MISO
tT
If next transfer begins here
for tT
, tl, tL
Minimum 1/2 SCK
tI tL
tL = Minimum leading time before the first SCK edge
tT = Minimum trailing time after the last SCK edge
tI = Minimum idling time between transfers (minimum SS high time)
tL, tT
, and tI are guaranteed for the master mode and required for the slave mode.
1 234 56 78910111213141516
SCK Edge Nr.
End of Idle State Begin of Idle State
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
428 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
In master mode, with slave select output enabled the SS line is always deasserted and reasserted between
successive transfers for at least minimum idle time.
14.4.3.3 CPHA = 1 Transfer Format
Some peripherals require the first SCK edge before the first data bit becomes available at the data out pin,
the second edge clocks data into the system. In this format, the first SCK edge is issued by setting the
CPHA bit at the beginning of the 8-cycle transfer operation.
The first edge of SCK occurs immediately after the half SCK clock cycle synchronization delay. This first
edge commands the slave to transfer its first data bit to the serial data input pin of the master.
A half SCK cycle later, the second edge appears on the SCK pin. This is the latching edge for both the
master and slave.
When the third edge occurs, the value previously latched from the serial data input pin is shifted into the
LSB or MSB of the SPI shift register, depending on LSBFE bit. After this edge, the next bit of the master
data is coupled out of the serial data output pin of the master to the serial input pin on the slave.
This process continues for a total of 16 edges on the SCK line with data being latched on even numbered
edges and shifting taking place on odd numbered edges.
Data reception is double buffered, data is serially shifted into the SPI shift register during the transfer and
is transferred to the parallel SPI Data Register after the last bit is shifted in.
After the 16th SCK edge:
• Data that was previously in the SPI Data Register of the master is now in the data register of the
slave, and data that was in the data register of the slave is in the master.
• The SPIF flag bit in SPISR is set indicating that the transfer is complete.
Figure 14-10 shows two clocking variations for CPHA = 1. The diagram may be interpreted as a master or
slave timing diagram because the SCK, MISO, and MOSI pins are connected directly between the master
and the slave. The MISO signal is the output from the slave, and the MOSI signal is the output from the
master. The SS line is the slave select input to the slave. The SS pin of the master must be either high or
reconfigured as a general-purpose output not affecting the SPI.
The SS line can remain active low between successive transfers (can be tied low at all times). This format
is sometimes preferred in systems having a single fixed master and a single slave that drive the MISO data
line.
• Back-to-back transfers in master mode
In master mode, if a transmission has completed and a new data byte is available in the SPI Data Register,
this byte is send out immediately without a trailing and minimum idle time.
The SPI interrupt request flag (SPIF) is common to both the master and slave modes. SPIF gets set one
half SCK cycle after the last SCK edge.
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 429
Rev 01.24
Figure 14-10. SPI Clock Format 1 (CPHA = 1)
14.4.4 SPI Baud Rate Generation
Baud rate generation consists of a series of divider stages. Six bits in the SPI Baud Rate register (SPPR2,
SPPR1, SPPR0, SPR2, SPR1, and SPR0) determine the divisor to the SPI module clock which results in
the SPI baud rate.
The SPI clock rate is determined by the product of the value in the baud rate preselection bits
(SPPR2–SPPR0) and the value in the baud rate selection bits (SPR2–SPR0). The module clock divisor
equation is shown in Figure 14-11
When all bits are clear (the default condition), the SPI module clock is divided by 2. When the selection
bits (SPR2–SPR0) are 001 and the preselection bits (SPPR2–SPPR0) are 000, the module clock divisor
becomes 4. When the selection bits are 010, the module clock divisor becomes 8 etc.
When the preselection bits are 001, the divisor determined by the selection bits is multiplied by 2. When
the preselection bits are 010, the divisor is multiplied by 3, etc. See Table 14-7 for baud rate calculations
for all bit conditions, based on a 25-MHz bus clock. The two sets of selects allows the clock to be divided
by a non-power of two to achieve other baud rates such as divide by 6, divide by 10, etc.
tL tT
for tT
, tl, tL
Minimum 1/2 SCK
tI tL
If next transfer begins here
Begin End
SCK (CPOL = 0)
SAMPLE I
CHANGE O
SEL SS (O)
Transfer
SCK (CPOL = 1)
MSB first (LSBFE = 0):
LSB first (LSBFE = 1):
MSB
LSB
LSB
MSB
Bit 5
Bit 2
Bit 6
Bit 1
Bit 4
Bit 3
Bit 3
Bit 4
Bit 2
Bit 5
Bit 1
Bit 6
CHANGE O
SEL SS (I)
MOSI pin
MISO pin
Master only
MOSI/MISO
tL = Minimum leading time before the first SCK edge, not required for back to back transfers
tT = Minimum trailing time after the last SCK edge
tI = Minimum idling time between transfers (minimum SS high time), not required for back to back transfers
1 234 56 78910111213141516SCK Edge Nr.
End of Idle State Begin of Idle State
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
430 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The baud rate generator is activated only when the SPI is in the master mode and a serial transfer is taking
place. In the other cases, the divider is disabled to decrease IDD current.
Figure 14-11. Baud Rate Divisor Equation
14.4.5 Special Features
14.4.5.1 SS Output
The SS output feature automatically drives the SS pin low during transmission to select external devices
and drives it high during idle to deselect external devices. When SS output is selected, the SS output pin
is connected to the SS input pin of the external device.
The SS output is available only in master mode during normal SPI operation by asserting SSOE and
MODFEN bit as shown in Table 14-3.
The mode fault feature is disabled while SS output is enabled.
NOTE
Care must be taken when using the SS output feature in a multimaster
system because the mode fault feature is not available for detecting system
errors between masters.
14.4.5.2 Bidirectional Mode (MOSI or MISO)
The bidirectional mode is selected when the SPC0 bit is set in SPI Control Register 2 (see Table 14-9). In
this mode, the SPI uses only one serial data pin for the interface with external device(s). The MSTR bit
decides which pin to use. The MOSI pin becomes the serial data I/O (MOMI) pin for the master mode, and
the MISO pin becomes serial data I/O (SISO) pin for the slave mode. The MISO pin in master mode and
MOSI pin in slave mode are not used by the SPI.
Table 14-9. Normal Mode and Bidirectional Mode
When SPE = 1 Master Mode MSTR = 1 Slave Mode MSTR = 0
Normal Mode
SPC0 = 0
Bidirectional Mode
SPC0 = 1
BaudRateDivisor SPPR 1+()2•SPR 1+()
=
SPI
MOSI
MISO
Serial Out
Serial In
SPI
MOSI
MISO
Serial In
Serial Out
SPI
MOMI
Serial Out
Serial In
BIDIROE SPI
SISO
Serial In
Serial Out
BIDIROE
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 431
Rev 01.24
The direction of each serial I/O pin depends on the BIDIROE bit. If the pin is configured as an output,
serial data from the shift register is driven out on the pin. The same pin is also the serial input to the shift
register.
The SCK is output for the master mode and input for the slave mode.
The SS is the input or output for the master mode, and it is always the input for the slave mode.
The bidirectional mode does not affect SCK and SS functions.
NOTE
In bidirectional master mode, with mode fault enabled, both data pins MISO
and MOSI can be occupied by the SPI, though MOSI is normally used for
transmissions in bidirectional mode and MISO is not used by the SPI. If a
mode fault occurs, the SPI is automatically switched to slave mode, in this
case MISO becomes occupied by the SPI and MOSI is not used. This has to
be considered, if the MISO pin is used for other purpose.
14.4.6 Error Conditions
The SPI has one error condition:
• Mode fault error
14.4.6.1 Mode Fault Error
If the SS input becomes low while the SPI is configured as a master, it indicates a system error where more
than one master may be trying to drive the MOSI and SCK lines simultaneously. This condition is not
permitted in normal operation, the MODF bit in the SPI Status Register is set automatically provided the
MODFEN bit is set.
In the special case where the SPI is in master mode and MODFEN bit is cleared, the SS pin is not used by
the SPI. In this special case, the mode fault error function is inhibited and MODF remains cleared. In case
the SPI system is configured as a slave, the SS pin is a dedicated input pin. Mode fault error doesn’t occur
in slave mode.
If a mode fault error occurs the SPI is switched to slave mode, with the exception that the slave output
buffer is disabled. So SCK, MISO and MOSI pins are forced to be high impedance inputs to avoid any
possibility of conflict with another output driver. A transmission in progress is aborted and the SPI is
forced into idle state.
If the mode fault error occurs in the bidirectional mode for a SPI system configured in master mode, output
enable of the MOMI (MOSI in bidirectional mode) is cleared if it was set. No mode fault error occurs in
the bidirectional mode for SPI system configured in slave mode.
The mode fault flag is cleared automatically by a read of the SPI Status Register (with MODF set) followed
by a write to SPI Control Register 1. If the mode fault flag is cleared, the SPI becomes a normal master or
slave again.
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
432 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
14.4.7 Operation in Run Mode
In run mode with the SPI system enable (SPE) bit in the SPI control register clear, the SPI system is in a
low-power, disabled state. SPI registers remain accessible, but clocks to the core of this module are
disabled.
14.4.8 Operation in Wait Mode
SPI operation in wait mode depends upon the state of the SPISWAI bit in SPI Control Register 2.
• If SPISWAI is clear, the SPI operates normally when the CPU is in wait mode
• If SPISWAI is set, SPI clock generation ceases and the SPI module enters a power conservation
state when the CPU is in wait mode.
— If SPISWAI is set and the SPI is configured for master, any transmission and reception in
progress stops at wait mode entry. The transmission and reception resumes when the SPI exits
wait mode.
— If SPISWAI is set and the SPI is configured as a slave, any transmission and reception in
progress continues if the SCK continues to be driven from the master. This keeps the slave
synchronized to the master and the SCK.
If the master transmits several bytes while the slave is in wait mode, the slave will continue to
send out bytes consistent with the operation mode at the start of wait mode (i.e. If the slave is
currently sending its SPIDR to the master, it will continue to send the same byte. Else if the
slave is currently sending the last received byte from the master, it will continue to send each
previous master byte).
NOTE
Care must be taken when expecting data from a master while the slave is in
wait or stop mode. Even though the shift register will continue to operate,
the rest of the SPI is shut down (i.e. a SPIF interrupt will not be generated
until exiting stop or wait mode). Also, the byte from the shift register will
not be copied into the SPIDR register until after the slave SPI has exited wait
or stop mode. A SPIF flag and SPIDR copy is only generated if wait mode
is entered or exited during a tranmission. If the slave enters wait mode in idle
mode and exits wait mode in idle mode, neither a SPIF nor a SPIDR copy
will occur.
14.4.9 Operation in Stop Mode
Stop mode is dependent on the system. The SPI enters stop mode when the module clock is disabled (held
high or low). If the SPI is in master mode and exchanging data when the CPU enters stop mode, the
transmission is frozen until the CPU exits stop mode. After stop, data to and from the external SPI is
exchanged correctly. In slave mode, the SPI will stay synchronized with the master.
The stop mode is not dependent on the SPISWAI bit.
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 433
Rev 01.24
14.5 Reset
The reset values of registers and signals are described in the Memory Map and Registers section (see
Section 14.3, “Memory Map and Register Definition”) which details the registers and their bit-fields.
• If a data transmission occurs in slave mode after reset without a write to SPIDR, it will transmit
garbage, or the byte last received from the master before the reset.
• Reading from the SPIDR after reset will always read a byte of zeros.
14.6 Interrupts
The SPIV3 only originates interrupt requests when SPI is enabled (SPE bit in SPICR1 set). The following
is a description of how the SPIV3 makes a request and how the MCU should acknowledge that request.
The interrupt vector offset and interrupt priority are chip dependent.
The interrupt flags MODF, SPIF and SPTEF are logically ORed to generate an interrupt request.
14.6.1 MODF
MODF occurs when the master detects an error on the SS pin. The master SPI must be configured for the
MODF feature (see Table 14-3). After MODF is set, the current transfer is aborted and the following bit is
changed:
• MSTR = 0, The master bit in SPICR1 resets.
The MODF interrupt is reflected in the status register MODF flag. Clearing the flag will also clear the
interrupt. This interrupt will stay active while the MODF flag is set. MODF has an automatic clearing
process which is described in Section 14.3.2.4, “SPI Status Register (SPISR).”
14.6.2 SPIF
SPIF occurs when new data has been received and copied to the SPI Data Register. After SPIF is set, it
does not clear until it is serviced. SPIF has an automatic clearing process which is described in
Section 14.3.2.4, “SPI Status Register (SPISR).”In the event that the SPIF is not serviced before the end
of the next transfer (i.e. SPIF remains active throughout another transfer), the latter transfers will be
ignored and no new data will be copied into the SPIDR.
14.6.3 SPTEF
SPTEF occurs when the SPI Data Register is ready to accept new data. After SPTEF is set, it does not clear
until it is serviced. SPTEF has an automatic clearing process which is described in Section 14.3.2.4, “SPI
Status Register (SPISR).”
Chapter 14 Serial Peripheral Interface (SPIV3) Block Description
434 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 435
Rev 01.24
Chapter 15
Timer Module (TIM16B8CV1) Block Description
15.1 Introduction
The basic timer consists of a 16-bit, software-programmable counter driven by a seven-stage
programmable prescaler.
This timer can be used for many purposes, including input waveform measurements while simultaneously
generating an output waveform. Pulse widths can vary from microseconds to many seconds.
This timer contains 8 complete input capture/output compare channels and one pulse accumulator. The
input capture function is used to detect a selected transition edge and record the time. The output compare
function is used for generating output signals or for timer software delays. The 16-bit pulse accumulator
is used to operate as a simple event counter or a gated time accumulator. The pulse accumulator shares
timer channel 7 when in event mode.
A full access for the counter registers or the input capture/output compare registers should take place in
one clock cycle. Accessing high byte and low byte separately for all of these registers may not yield the
same result as accessing them in one word.
15.1.1 Features
The TIM16B8CV1 includes these distinctive features:
• Eight input capture/output compare channels.
• Clock prescaling.
• 16-bit counter.
• 16-bit pulse accumulator.
Table 15-1. Revision History
Version
Number Revision Dates Effective
Date Author Description of Changes
01.03 06 Feb 2006 06 Feb 2006 S. Chinnam Corrected the type at 0x006 and later in the document
from TSCR2 and TSCR1
01.04 08 July 2008 08 July 2008 S. Chinnam Revised flag clearing procedure, whereby TEN bit must be
set when clearing flags.
01.05 05 May 2010 05 May 2010 Ame Wang -in 15.3.2.8/15-446,add Table 15-11
-in 15.3.2.11/15-450,TCRE bit description part,add Note
-in 15.4.3/15-459,add Figure 15-29
Chapter 15 Timer Module (TIM16B8CV1) Block Description
436 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
15.1.2 Modes of Operation
Stop: Timer is off because clocks are stopped.
Freeze: Timer counter keep on running, unless TSFRZ in TSCR (0x0006) is set to 1.
Wait: Counters keep on running, unless TSWAI in TSCR (0x0006) is set to 1.
Normal: Timer counter keep on running, unless TEN in TSCR (0x0006) is cleared to 0.
15.1.3 Block Diagrams
Figure 15-1. TIM16B8CV1 Block Diagram
Prescaler
16-bit Counter
Input capture
Output compare
16-bit
Pulse accumulator
IOC0
IOC2
IOC1
IOC5
IOC3
IOC4
IOC6
IOC7
PA input
interrupt
PA overflow
interrupt
Timer overflow
interrupt
Timer channel 0
interrupt
Timer channel 7
interrupt
Registers
Bus clock
Input capture
Output compare
Input capture
Output compare
Input capture
Output compare
Input capture
Output compare
Input capture
Output compare
Input capture
Output compare
Input capture
Output compare
Channel 0
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 437
Rev 01.24
Figure 15-2. 16-Bit Pulse Accumulator Block Diagram
Figure 15-3. Interrupt Flag Setting
Edge detector
Intermodule Bus
PT7
M clock
Divide by 64
Clock select
CLK0
CLK1 4:1 MUX
TIMCLK
PAC LK
PACLK / 256
PACLK / 65536
Prescaled clock
(PCLK)
(Timer clock)
Interrupt
MUX
(PAMOD)
PACNT
PTn
Edge detector
16-bit Main Timer
TCn Input Capture Reg.
Set CnF Interrupt
Chapter 15 Timer Module (TIM16B8CV1) Block Description
438 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 15-4. Channel 7 Output Compare/Pulse Accumulator Logic
NOTE
For more information see the respective functional descriptions in
Section 15.4, “Functional Description,” of this document.
15.2 External Signal Description
The TIM16B8CV1 module has a total of eight external pins.
15.2.1 IOC7 — Input Capture and Output Compare Channel 7 Pin
This pin serves as input capture or output compare for channel 7. This can also be configured as pulse
accumulator input.
15.2.2 IOC6 — Input Capture and Output Compare Channel 6 Pin
This pin serves as input capture or output compare for channel 6.
15.2.3 IOC5 — Input Capture and Output Compare Channel 5 Pin
This pin serves as input capture or output compare for channel 5.
15.2.4 IOC4 — Input Capture and Output Compare Channel 4 Pin
This pin serves as input capture or output compare for channel 4. Pin
15.2.5 IOC3 — Input Capture and Output Compare Channel 3 Pin
This pin serves as input capture or output compare for channel 3.
PULSE
ACCUMULATOR PAD
OM7
OL7
OC7M7
CHANNEL 7 OUTPUT COMPARE
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 439
Rev 01.24
15.2.6 IOC2 — Input Capture and Output Compare Channel 2 Pin
This pin serves as input capture or output compare for channel 2.
15.2.7 IOC1 — Input Capture and Output Compare Channel 1 Pin
This pin serves as input capture or output compare for channel 1.
15.2.8 IOC0 — Input Capture and Output Compare Channel 0 Pin
This pin serves as input capture or output compare for channel 0.
NOTE
For the description of interrupts see Section 15.6, “Interrupts”.
15.3 Memory Map and Register Definition
This section provides a detailed description of all memory and registers.
15.3.1 Module Memory Map
The memory map for the TIM16B8CV1 module is given below in Table 15-2. The address listed for each
register is the address offset. The total address for each register is the sum of the base address for the
TIM16B8CV1 module and the address offset for each register.
Chapter 15 Timer Module (TIM16B8CV1) Block Description
440 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 15-2. TIM16B8CV1 Memory Map
Address Offset Use Access
0x0000 Timer Input Capture/Output Compare Select (TIOS) R/W
0x0001 Timer Compare Force Register (CFORC) R/W(1)
1. Always read 0x0000.
0x0002 Output Compare 7 Mask Register (OC7M) R/W
0x0003 Output Compare 7 Data Register (OC7D) R/W
0x0004 Timer Count Register (TCNT(hi)) R/W(2)
2. Only writable in special modes (test_mode = 1).
0x0005 Timer Count Register (TCNT(lo)) R/W2
0x0006 Timer System Control Register1 (TSCR1) R/W
0x0007 Timer Toggle Overflow Register (TTOV) R/W
0x0008 Timer Control Register1 (TCTL1) R/W
0x0009 Timer Control Register2 (TCTL2) R/W
0x000A Timer Control Register3 (TCTL3) R/W
0x000B Timer Control Register4 (TCTL4) R/W
0x000C Timer Interrupt Enable Register (TIE) R/W
0x000D Timer System Control Register2 (TSCR2) R/W
0x000E Main Timer Interrupt Flag1 (TFLG1) R/W
0x000F Main Timer Interrupt Flag2 (TFLG2) R/W
0x0010 Timer Input Capture/Output Compare Register 0 (TC0(hi)) R/W(3)
3. Write to these registers have no meaning or effect during input capture.
0x0011 Timer Input Capture/Output Compare Register 0 (TC0(lo)) R/W3
0x0012 Timer Input Capture/Output Compare Register 1 (TC1(hi)) R/W3
0x0013 Timer Input Capture/Output Compare Register 1 (TC1(lo)) R/W3
0x0014 Timer Input Capture/Output Compare Register 2 (TC2(hi)) R/W3
0x0015 Timer Input Capture/Output Compare Register 2 (TC2(lo)) R/W3
0x0016 Timer Input Capture/Output Compare Register 3 (TC3(hi)) R/W3
0x0017 Timer Input Capture/Output Compare Register 3 (TC3(lo)) R/W3
0x0018 Timer Input Capture/Output Compare Register4 (TC4(hi)) R/W3
0x0019 Timer Input Capture/Output Compare Register 4 (TC4(lo)) R/W3
0x001A Timer Input Capture/Output Compare Register 5 (TC5(hi)) R/W3
0x001B Timer Input Capture/Output Compare Register 5 (TC5(lo)) R/W3
0x001C Timer Input Capture/Output Compare Register 6 (TC6(hi)) R/W3
0x001D Timer Input Capture/Output Compare Register 6 (TC6(lo)) R/W3
0x001E Timer Input Capture/Output Compare Register 7 (TC7(hi)) R/W3
0x001F Timer Input Capture/Output Compare Register 7 (TC7(lo)) R/W3
0x0020 16-Bit Pulse Accumulator Control Register (PACTL) R/W
0x0021 Pulse Accumulator Flag Register (PAFLG) R/W
0x0022 Pulse Accumulator Count Register (PACNT(hi)) R/W
0x0023 Pulse Accumulator Count Register (PACNT(lo)) R/W
0x0024 – 0x002C Reserved — (4)
4. Write has no effect; return 0 on read
0x002D Timer Test Register (TIMTST) R/W2
0x002E – 0x002F Reserved — 4
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 441
Rev 01.24
15.3.2 Register Descriptions
This section consists of register descriptions in address order. Each description includes a standard
register diagram with an associated figure number. Details of register bit and field function follow the
register diagrams, in bit order.
Register
Name Bit 7 654321Bit 0
0x0000
TIOS
RIOS7 IOS6 IOS5 IOS4 IOS3 IOS2 IOS1 IOS0
W
0x0001
CFORC
R00000000
W FOC7 FOC6 FOC5 FOC4 FOC3 FOC2 FOC1 FOC0
0x0002
OC7M
ROC7M7 OC7M6 OC7M5 OC7M4 OC7M3 OC7M2 OC7M1 OC7M0
W
0x0003
OC7D
ROC7D7 OC7D6 OC7D5 OC7D4 OC7D3 OC7D2 OC7D1 OC7D0
W
0x0004
TCNTH
RTCNT15 TCNT14 TCNT13 TCNT12 TCNT11 TCNT10 TCNT9 TCNT8
W
0x0005
TCNTL
RTCNT7 TCNT6 TCNT5 TCNT4 TCNT3 TCNT2 TCNT1 TCNT0
W
0x0006
TSCR1
RTEN TSWAI TSFRZ TFFCA 0000
W
0x0007
TTOV
RTOV7 TOV6 TOV5 TOV4 TOV3 TOV2 TOV1 TOV0
W
0x0008
TCTL1
ROM7 OL7 OM6 OL6 OM5 OL5 OM4 OL4
W
0x0009
TCTL2
ROM3 OL3 OM2 OL2 OM1 OL1 OM0 OL0
W
0x000A
TCTL3
REDG7B EDG7A EDG6B EDG6A EDG5B EDG5A EDG4B EDG4A
W
0x000B
TCTL4
REDG3B EDG3A EDG2B EDG2A EDG1B EDG1A EDG0B EDG0A
W
0x000C
TIE
RC7I C6I C5I C4I C3I C2I C1I C0I
W
= Unimplemented or Reserved
Figure 15-5. TIM16B8CV1 Register Summary
Chapter 15 Timer Module (TIM16B8CV1) Block Description
442 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
15.3.2.1 Timer Input Capture/Output Compare Select (TIOS)
Read: Anytime
0x000D
TSCR2
RTOI 000
TCRE PR2 PR1 PR0
W
0x000E
TFLG1
RC7F C6F C5F C4F C3F C2F C1F C0F
W
0x000F
TFLG2
RTOF 0000000
W
0x0010–0x001F
TCxH–TCxL
RBit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
W
RBit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
0x0020
PACTL
R0 PAEN PAMOD PEDGE CLK1 CLK0 PAOVI PAI
W
0x0021
PAFLG
R000000
PAOVF PAIF
W
0x0022
PACNTH
RPACNT15 PACNT14 PACNT13 PACNT12 PACNT11 PACNT10 PACNT9 PACNT8
W
0x0023
PACNTL
RPACNT7 PACNT6 PACNT5 PACNT4 PACNT3 PACNT2 PACNT1 PACNT0
W
0x0024–0x002F
Reserved
R
W
Module Base + 0x0000
76543210
R
IOS7 IOS6 IOS5 IOS4 IOS3 IOS2 IOS1 IOS0
W
Reset 0 0 0 00000
Figure 15-6. Timer Input Capture/Output Compare Select (TIOS)
Register
Name Bit 7 654321Bit 0
= Unimplemented or Reserved
Figure 15-5. TIM16B8CV1 Register Summary (continued)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 443
Rev 01.24
Write: Anytime
15.3.2.2 Timer Compare Force Register (CFORC)
Read: Anytime but will always return 0x0000 (1 state is transient)
Write: Anytime
15.3.2.3 Output Compare 7 Mask Register (OC7M)
Read: Anytime
Write: Anytime
Table 15-3. TIOS Field Descriptions
Field Description
7:0
IOS[7:0]
Input Capture or Output Compare Channel Configuration
0 The corresponding channel acts as an input capture.
1 The corresponding channel acts as an output compare.
Module Base + 0x0001
76543210
R00000000
W FOC7 FOC6 FOC5 FOC4 FOC3 FOC2 FOC1 FOC0
Reset 0 0 0 00000
Figure 15-7. Timer Compare Force Register (CFORC)
Table 15-4. CFORC Field Descriptions
Field Description
7:0
FOC[7:0]
Force Output Compare Action for Channel 7:0 — A write to this register with the corresponding data bit(s) set
causes the action which is programmed for output compare “x” to occur immediately. The action taken is the
same as if a successful comparison had just taken place with the TCx register except the interrupt flag does not
get set.
Note: A successful channel 7 output compare overrides any channel 6:0 compares. If forced output compare on
any channel occurs at the same time as the successful output compare then forced output compare action
will take precedence and interrupt flag won’t get set.
Module Base + 0x0002
76543210
R
OC7M7 OC7M6 OC7M5 OC7M4 OC7M3 OC7M2 OC7M1 OC7M0
W
Reset 0 0 0 00000
Figure 15-8. Output Compare 7 Mask Register (OC7M)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
444 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
15.3.2.4 Output Compare 7 Data Register (OC7D)
Read: Anytime
Write: Anytime
15.3.2.5 Timer Count Register (TCNT)
Table 15-5. OC7M Field Descriptions
Field Description
7:0
OC7M[7:0]
Output Compare 7 Mask — Setting the OC7Mx (x ranges from 0 to 6) will set the corresponding port to be an
output port when the corresponding TIOSx (x ranges from 0 to 6) bit is set to be an output compare.
Note: A successful channel 7 output compare overrides any channel 6:0 compares. For each OC7M bit that is
set, the output compare action reflects the corresponding OC7D bit.
Module Base + 0x0003
76543210
R
OC7D7 OC7D6 OC7D5 OC7D4 OC7D3 OC7D2 OC7D1 OC7D0
W
Reset 0 0 0 00000
Figure 15-9. Output Compare 7 Data Register (OC7D)
Table 15-6. OC7D Field Descriptions
Field Description
7:0
OC7D[7:0]
Output Compare 7 Data — A channel 7 output compare can cause bits in the output compare 7 data register
to transfer to the timer port data register depending on the output compare 7 mask register.
Module Base + 0x0004
15 14 13 12 11 10 9 9
R
TCNT15 TCNT14 TCNT13 TCNT12 TCNT11 TCNT10 TCNT9 TCNT8
W
Reset 0 0 0 00000
Figure 15-10. Timer Count Register High (TCNTH)
Module Base + 0x0005
76543210
R
TCNT7 TCNT6 TCNT5 TCNT4 TCNT3 TCNT2 TCNT1 TCNT0
W
Reset 0 0 0 00000
Figure 15-11. Timer Count Register Low (TCNTL)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 445
Rev 01.24
The 16-bit main timer is an up counter.
A full access for the counter register should take place in one clock cycle. A separate read/write for high
byte and low byte will give a different result than accessing them as a word.
Read: Anytime
Write: Has no meaning or effect in the normal mode; only writable in special modes (test_mode = 1).
The period of the first count after a write to the TCNT registers may be a different size because the write
is not synchronized with the prescaler clock.
15.3.2.6 Timer System Control Register 1 (TSCR1)
Read: Anytime
Write: Anytime
Module Base + 0x0006
76543210
R
TEN TSWAI TSFRZ TFFCA
0000
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 15-12. Timer System Control Register 1 (TSCR1)
Table 15-7. TSCR1 Field Descriptions
Field Description
7
TEN
Timer Enable
0 Disables the main timer, including the counter. Can be used for reducing power consumption.
1 Allows the timer to function normally.
If for any reason the timer is not active, there is no ÷64 clock for the pulse accumulator because the ÷64 is
generated by the timer prescaler.
6
TSWAI
Timer Module Stops While in Wait
0 Allows the timer module to continue running during wait.
1 Disables the timer module when the MCU is in the wait mode. Timer interrupts cannot be used to get the MCU
out of wait.
TSWAI also affects pulse accumulator.
Chapter 15 Timer Module (TIM16B8CV1) Block Description
446 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
15.3.2.7 Timer Toggle On Overflow Register 1 (TTOV)
Read: Anytime
Write: Anytime
15.3.2.8 Timer Control Register 1/Timer Control Register 2 (TCTL1/TCTL2)
5
TSFRZ
Timer Stops While in Freeze Mode
0 Allows the timer counter to continue running while in freeze mode.
1 Disables the timer counter whenever the MCU is in freeze mode. This is useful for emulation.
TSFRZ does not stop the pulse accumulator.
4
TFFCA
Timer Fast Flag Clear All
0 Allows the timer flag clearing to function normally.
1 For TFLG1(0x000E), a read from an input capture or a write to the output compare channel (0x0010–0x001F)
causes the corresponding channel flag, CnF, to be cleared. For TFLG2 (0x000F), any access to the TCNT
register (0x0004, 0x0005) clears the TOF flag. Any access to the PACNT registers (0x0022, 0x0023) clears
the PAOVF and PAIF flags in the PAFLG register (0x0021). This has the advantage of eliminating software
overhead in a separate clear sequence. Extra care is required to avoid accidental flag clearing due to
unintended accesses.
Module Base + 0x0007
76543210
R
TOV7 TOV6 TOV5 TOV4 TOV3 TOV2 TOV1 TOV0
W
Reset 0 0 0 00000
Figure 15-13. Timer Toggle On Overflow Register 1 (TTOV)
Table 15-8. TTOV Field Descriptions
Field Description
7:0
TOV[7:0]
Toggle On Overflow Bits — TOVx toggles output compare pin on overflow. This feature only takes effect when
in output compare mode. When set, it takes precedence over forced output compare but not channel 7 override
events.
0 Toggle output compare pin on overflow feature disabled.
1 Toggle output compare pin on overflow feature enabled.
Module Base + 0x0008
76543210
R
OM7 OL7 OM6 OL6 OM5 OL5 OM4 OL4
W
Reset 0 0 0 00000
Figure 15-14. Timer Control Register 1 (TCTL1)
Table 15-7. TSCR1 Field Descriptions (continued)
Field Description
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 447
Rev 01.24
Read: Anytime
Write: Anytime
To operate the 16-bit pulse accumulator independently of input capture or output compare 7 and 0
respectively the user must set the corresponding bits IOSx = 1, OMx = 0 and OLx = 0. OC7M7 in the
OC7M register must also be cleared.
To enable output action using the OM7 and OL7 bits on the timer port,the corresponding bit OC7M7 in
the OC7M register must also be cleared. The settings for these bits can be seen in Table 15-11
Table 15-11. The OC7 and OCx event priority
Module Base + 0x0009
76543210
R
OM3 OL3 OM2 OL2 OM1 OL1 OM0 OL0
W
Reset 0 0 0 00000
Figure 15-15. Timer Control Register 2 (TCTL2)
Table 15-9. TCTL1/TCTL2 Field Descriptions
Field Description
7:0
OMx
Output Mode — These eight pairs of control bits are encoded to specify the output action to be taken as a result
of a successful OCx compare. When either OMx or OLx is 1, the pin associated with OCx becomes an output
tied to OCx.
Note: To enable output action by OMx bits on timer port, the corresponding bit in OC7M should be cleared.
7:0
OLx
Output Level — These eight pairs of control bits are encoded to specify the output action to be taken as a result
of a successful OCx compare. When either OMx or OLx is 1, the pin associated with OCx becomes an output
tied to OCx.
Note: To enable output action by OLx bits on timer port, the corresponding bit in OC7M should be cleared.
Table 15-10. Compare Result Output Action
OMx OLx Action
0 0 Timer disconnected from output pin logic
0 1 Toggle OCx output line
1 0 Clear OCx output line to zero
1 1 Set OCx output line to one
OC7M7=0 OC7M7=1
OC7Mx=1 OC7Mx=0 OC7Mx=1 OC7Mx=0
TC7=TCx TC7>TCx TC7=TCx TC7>TCx TC7=TCx TC7>TCx TC7=TCx TC7>TCx
IOCx=OC7Dx
IOC7=OM7/O
L7
IOCx=OC7Dx
+OMx/OLx
IOC7=OM7/O
L7
IOCx=OMx/OLx
IOC7=OM7/OL7
IOCx=OC7Dx
IOC7=OC7D7
IOCx=OC7Dx
+OMx/OLx
IOC7=OC7D7
IOCx=OMx/OLx
IOC7=OC7D7
Chapter 15 Timer Module (TIM16B8CV1) Block Description
448 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Note: in Table 15-11, the IOS7 and IOSx should be set to 1
IOSx is the register TIOS bit x,
OC7Mx is the register OC7M bit x,
TCx is timer Input Capture/Output Compare register,
IOCx is channel x,
OMx/OLx is the register TCTL1/TCTL2,
OC7Dx is the register OC7D bit x.
IOCx = OC7Dx+ OMx/OLx, means that both OC7 event and OCx event will change channel x value.
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 449
Rev 01.24
15.3.2.9 Timer Control Register 3/Timer Control Register 4 (TCTL3 and TCTL4)
Read: Anytime
Write: Anytime.
Module Base + 0x000A
76543210
R
EDG7B EDG7A EDG6B EDG6A EDG5B EDG5A EDG4B EDG4A
W
Reset 0 0 0 00000
Figure 15-16. Timer Control Register 3 (TCTL3)
Module Base + 0x000B
76543210
R
EDG3B EDG3A EDG2B EDG2A EDG1B EDG1A EDG0B EDG0A
W
Reset 0 0 0 00000
Figure 15-17. Timer Control Register 4 (TCTL4)
Table 15-12. TCTL3/TCTL4 Field Descriptions
Field Description
7:0
EDGnB
EDGnA
Input Capture Edge Control — These eight pairs of control bits configure the input capture edge detector
circuits.
Table 15-13. Edge Detector Circuit Configuration
EDGnB EDGnA Configuration
0 0 Capture disabled
0 1 Capture on rising edges only
1 0 Capture on falling edges only
1 1 Capture on any edge (rising or falling)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
450 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
15.3.2.10 Timer Interrupt Enable Register (TIE)
Read: Anytime
Write: Anytime.
15.3.2.11 Timer System Control Register 2 (TSCR2)
Read: Anytime
Write: Anytime.
Module Base + 0x000C
76543210
R
C7I C6I C5I C4I C3I C2I C1I C0I
W
Reset 0 0 0 00000
Figure 15-18. Timer Interrupt Enable Register (TIE)
Table 15-14. TIE Field Descriptions
Field Description
7:0
C7I:C0I
Input Capture/Output Compare “x” Interrupt Enable — The bits in TIE correspond bit-for-bit with the bits in
the TFLG1 status register. If cleared, the corresponding flag is disabled from causing a hardware interrupt. If set,
the corresponding flag is enabled to cause a interrupt.
Module Base + 0x000D
76543210
R
TOI
000
TCRE PR2 PR1 PR0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 15-19. Timer System Control Register 2 (TSCR2)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 451
Rev 01.24
NOTE
The newly selected prescale factor will not take effect until the next
synchronized edge where all prescale counter stages equal zero.
15.3.2.12 Main Timer Interrupt Flag 1 (TFLG1)
Read: Anytime
Table 15-15. TSCR2 Field Descriptions
Field Description
7
TOI
Timer Overflow Interrupt Enable
0 Interrupt inhibited.
1 Hardware interrupt requested when TOF flag set.
3
TCRE
Timer Counter Reset Enable — This bit allows the timer counter to be reset by a successful output compare 7
event. This mode of operation is similar to an up-counting modulus counter.
0 Counter reset inhibited and counter free runs.
1 Counter reset by a successful output compare 7.
Note: If TC7 = 0x0000 and TCRE = 1, TCNT will stay at 0x0000 continuously. If TC7 = 0xFFFF and TCRE = 1,
TOF will never be set when TCNT is reset from 0xFFFF to 0x0000.
Note: TCRE=1 and TC7!=0, the TCNT cycle period will be TC7 x "prescaler counter width" + "1 Bus Clock", for
a more detail explanation please refer to Section 15.4.3, “Output Compare
2
PR[2:0]
Timer Prescaler Select — These three bits select the frequency of the timer prescaler clock derived from the
Bus Clock as shown in Table 15-16.
Table 15-16. Timer Clock Selection
PR2 PR1 PR0 Timer Clock
0 0 0 Bus Clock / 1
0 0 1 Bus Clock / 2
0 1 0 Bus Clock / 4
0 1 1 Bus Clock / 8
1 0 0 Bus Clock / 16
1 0 1 Bus Clock / 32
1 1 0 Bus Clock / 64
1 1 1 Bus Clock / 128
Module Base + 0x000E
76543210
R
C7F C6F C5F C4F C3F C2F C1F C0F
W
Reset 0 0 0 00000
Figure 15-20. Main Timer Interrupt Flag 1 (TFLG1)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
452 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Write: Used in the clearing mechanism (set bits cause corresponding bits to be cleared). Writing a zero
will not affect current status of the bit.
15.3.2.13 Main Timer Interrupt Flag 2 (TFLG2)
TFLG2 indicates when interrupt conditions have occurred. To clear a bit in the flag register, write the bit
to one while TEN of TSCR1 is set to one.
Read: Anytime
Write: Used in clearing mechanism (set bits cause corresponding bits to be cleared).
Any access to TCNT will clear TFLG2 register if the TFFCA bit in TSCR register is set.
Table 15-17. TRLG1 Field Descriptions
Field Description
7:0
C[7:0]F
Input Capture/Output Compare Channel “x” Flag — These flags are set when an input capture or output
compare event occurs. Clearing requires writing a one to the corresponding flag bit when TEN is set to one.
When TFFCA bit in TSCR register is set, a read from an input capture or a write into an output compare channel
(0x0010–0x001F) will cause the corresponding channel flag CxF to be cleared.
Module Base + 0x000F
76543210
R
TOF
0000000
W
Reset 0 0 0 00000
Unimplemented or Reserved
Figure 15-21. Main Timer Interrupt Flag 2 (TFLG2)
Table 15-18. TRLG2 Field Descriptions
Field Description
7
TOF
Timer Overflow Flag — Set when 16-bit free-running timer overflows from 0xFFFF to 0x0000. Clearing this bit
requires writing a one to bit 7 of TFLG2 register while TEN bit of TSCR1 is set to one. (See also TCRE control
bit explanation.)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 453
Rev 01.24
15.3.2.14 Timer Input Capture/Output Compare Registers High and Low 0–7
(TCxH and TCxL)
Depending on the TIOS bit for the corresponding channel, these registers are used to latch the value of the
free-running counter when a defined transition is sensed by the corresponding input capture edge detector
or to trigger an output action for output compare.
Read: Anytime
Write: Anytime for output compare function.Writes to these registers have no meaning or effect during
input capture. All timer input capture/output compare registers are reset to 0x0000.
NOTE
Read/Write access in byte mode for high byte should takes place before low
byte otherwise it will give a different result.
Module Base + 0x0010 = TC0H
0x0012 = TC1H
0x0014 = TC2H
0x0016 = TC3H
0x0018 = TC4H
0x001A = TC5H
0x001C = TC6H
0x001E = TC7H
15 14 13 12 11 10 9 0
R
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
W
Reset 00000000
Figure 15-22. Timer Input Capture/Output Compare Register x High (TCxH)
Module Base + 0x0011 = TC0L
0x0013 = TC1L
0x0015 = TC2L
0x0017 = TC3L
0x0019 = TC4L
0x001B = TC5L
0x001D = TC6L
0x001F = TC7L
76543210
R
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
Reset 00000000
Figure 15-23. Timer Input Capture/Output Compare Register x Low (TCxL)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
454 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
15.3.2.15 16-Bit Pulse Accumulator Control Register (PACTL)
When PAEN is set, the PACT is enabled.The PACT shares the input pin with IOC7.
Read: Any time
Write: Any time
Module Base + 0x0020
76543210
R0
PAEN PAMOD PEDGE CLK1 CLK0 PAOVI PAI
W
Reset 0 0 0 00000
Unimplemented or Reserved
Figure 15-24. 16-Bit Pulse Accumulator Control Register (PACTL)
Table 15-19. PACTL Field Descriptions
Field Description
6
PAEN
Pulse Accumulator System Enable — PAEN is independent from TEN. With timer disabled, the pulse
accumulator can function unless pulse accumulator is disabled.
0 16-Bit Pulse Accumulator system disabled.
1 Pulse Accumulator system enabled.
5
PAMOD
Pulse Accumulator Mode — This bit is active only when the Pulse Accumulator is enabled (PAEN = 1). See
Table 15-20.
0 Event counter mode.
1 Gated time accumulation mode.
4
PEDGE
Pulse Accumulator Edge Control — This bit is active only when the Pulse Accumulator is enabled (PAEN = 1).
For PAMOD bit = 0 (event counter mode). See Table 15-20.
0 Falling edges on IOC7 pin cause the count to be incremented.
1 Rising edges on IOC7 pin cause the count to be incremented.
For PAMOD bit = 1 (gated time accumulation mode).
0 IOC7 input pin high enables M (bus clock) divided by 64 clock to Pulse Accumulator and the trailing falling
edge on IOC7 sets the PAIF flag.
1 IOC7 input pin low enables M (bus clock) divided by 64 clock to Pulse Accumulator and the trailing rising edge
on IOC7 sets the PAIF flag.
3:2
CLK[1:0]
Clock Select Bits — Refer to Table 15-21.
1
PAOV I
Pulse Accumulator Overflow Interrupt Enable
0 Interrupt inhibited.
1 Interrupt requested if PAOVF is set.
0
PAI
Pulse Accumulator Input Interrupt Enable
0 Interrupt inhibited.
1 Interrupt requested if PAIF is set.
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 455
Rev 01.24
NOTE
If the timer is not active (TEN = 0 in TSCR), there is no divide-by-64
because the ÷64 clock is generated by the timer prescaler.
For the description of PACLK please refer Figure 15-24.
If the pulse accumulator is disabled (PAEN = 0), the prescaler clock from the timer is always used as an
input clock to the timer counter. The change from one selected clock to the other happens immediately
after these bits are written.
15.3.2.16 Pulse Accumulator Flag Register (PAFLG)
Read: Anytime
Write: Anytime
When the TFFCA bit in the TSCR register is set, any access to the PACNT register will clear all the flags
in the PAFLG register. Timer module must stay enabled (TEN =1) while clearing thse bits.
Table 15-20. Pin Action
PAMOD PEDGE Pin Action
0 0 Falling edge
0 1 Rising edge
1 0 Div. by 64 clock enabled with pin high level
1 1 Div. by 64 clock enabled with pin low level
Table 15-21. Timer Clock Selection
CLK1 CLK0 Timer Clock
0 0 Use timer prescaler clock as timer counter clock
0 1 Use PACLK as input to timer counter clock
1 0 Use PACLK/256 as timer counter clock frequency
1 1 Use PACLK/65536 as timer counter clock frequency
Module Base + 0x0021
76543210
R000000
PAOVF PAIF
W
Reset 0 0 0 00000
Unimplemented or Reserved
Figure 15-25. Pulse Accumulator Flag Register (PAFLG)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
456 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 15-22. PAFLG Field Descriptions
Field Description
1
PAOV F
Pulse Accumulator Overflow Flag — Set when the 16-bit pulse accumulator overflows from 0xFFFF to 0x0000.
Clearing this bit requires wirting a one to this bit in the PAFLG register while TEN bit of TSCR1 register is set to
one.
0
PAIF
Pulse Accumulator Input edge Flag — Set when the selected edge is detected at the IOC7 input pin.In event
mode the event edge triggers PAIF and in gated time accumulation mode the trailing edge of the gate signal at
the IOC7 input pin triggers PAIF.
Clearing this bit requires writing a one to this bit in the PAFLG register while TEN bit of TSCR1 register is set to
one. Any access to the PACNT register will clear all the flags in this register when TFFCA bit in register
TSCR(0x0006) is set.
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 457
Rev 01.24
15.3.2.17 Pulse Accumulators Count Registers (PACNT)
Read: Anytime
Write: Anytime
These registers contain the number of active input edges on its input pin since the last reset.
When PACNT overflows from 0xFFFF to 0x0000, the Interrupt flag PAOVF in PAFLG (0x0021) is set.
Full count register access should take place in one clock cycle. A separate read/write for high byte and low
byte will give a different result than accessing them as a word.
NOTE
Reading the pulse accumulator counter registers immediately after an active
edge on the pulse accumulator input pin may miss the last count because the
input has to be synchronized with the bus clock first.
15.4 Functional Description
This section provides a complete functional description of the timer TIM16B8CV1 block. Please refer to
the detailed timer block diagram in Figure 15-28 as necessary.
Module Base + 0x0022
15 14 13 12 11 10 9 0
R
PACNT15 PACNT14 PACNT13 PACNT12 PACNT11 PACNT10 PACNT9 PACNT8
W
Reset 0 0 0 00000
Figure 15-26. Pulse Accumulator Count Register High (PACNTH)
Module Base + 0x0023
76543210
R
PACNT7 PACNT6 PACNT5 PACNT4 PACNT3 PACNT2 PACNT1 PACNT0
W
Reset 0 0 0 00000
Figure 15-27. Pulse Accumulator Count Register Low (PACNTL)
Chapter 15 Timer Module (TIM16B8CV1) Block Description
458 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 15-28. Detailed Timer Block Diagram
15.4.1 Prescaler
The prescaler divides the bus clock by 1,2,4,8,16,32,64 or 128. The prescaler select bits, PR[2:0], select
the prescaler divisor. PR[2:0] are in timer system control register 2 (TSCR2).
PRESCALER
CHANNEL 0
IOC0 PIN
16-BIT COUNTER
LOGIC
PR[2:1:0]
DIVIDE-BY-64
TC0
EDGE
DETECT
PACNT(hi):PACNT(lo)
PAOVF PEDGE
PAOVI
TEN
PAE
16-BIT COMPARATOR
TCNT(hi):TCNT(lo)
CHANNEL 1
TC1
16-BIT COMPARATOR
16-BIT COUNTER
INTERRUPT
LOGIC
TOF
TOI
C0F
C1F
EDGE
DETECT
IOC1 PIN
LOGIC
EDGE
DETECT
CxF
CHANNEL7
TC7
16-BIT COMPARATOR C7F
IOC7 PIN
LOGIC
EDGE
DETECT
OM:OL0
TOV0
OM:OL1
TOV1
OM:O73
TOV7
EDG1A EDG1B
EDG7A
EDG7B
EDG0B
TCRE
PAIF
CLEAR COUNTER
PAIF
PAI
INTERRUPT
LOGIC
CxI
INTERRUPT
REQUEST
PAOVF
CH. 7 COMPARE
CH.7 CAPTURE
CH. 1 CAPTURE
MUX
CLK[1:0]
PACLK
PACLK/256
PACLK/65536
IOC1 PIN
IOC0 PIN
IOC7 PIN
PACLK
PACLK/256
PACLK/65536
TE
CH. 1 COMPARE
CH. 0COMPARE
CH. 0 CAPTURE
PA INPUT
CHANNEL2
EDG0A
channel 7 output
compare
IOC0
IOC1
IOC7
Bus Clock
Bus Clock
PAOVF
PAOVI
TOF
C0F
C1F
C7F
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 459
Rev 01.24
15.4.2 Input Capture
Clearing the I/O (input/output) select bit, IOSx, configures channel x as an input capture channel. The
input capture function captures the time at which an external event occurs. When an active edge occurs on
the pin of an input capture channel, the timer transfers the value in the timer counter into the timer channel
registers, TCx.
The minimum pulse width for the input capture input is greater than two bus clocks.
An input capture on channel x sets the CxF flag. The CxI bit enables the CxF flag to generate interrupt
requests. Timer module must stay enabled (TEN bit of TSCR1 must be set to one) while clearing CxF
(writing one to CxF).
15.4.3 Output Compare
Setting the I/O select bit, IOSx, configures channel x as an output compare channel. The output compare
function can generate a periodic pulse with a programmable polarity, duration, and frequency. When the
timer counter reaches the value in the channel registers of an output compare channel, the timer can set,
clear, or toggle the channel pin. An output compare on channel x sets the CxF flag. The CxI bit enables the
CxF flag to generate interrupt requests. Timer module must stay enabled (TEN bit of TSCR1 register must
be set to one) while clearing CxF (writing one to CxF).
The output mode and level bits, OMx and OLx, select set, clear, toggle on output compare. Clearing both
OMx and OLx disconnects the pin from the output logic.
Setting a force output compare bit, FOCx, causes an output compare on channel x. A forced output
compare does not set the channel flag.
A successful output compare on channel 7 overrides output compares on all other output compare
channels. The output compare 7 mask register masks the bits in the output compare 7 data register. The
timer counter reset enable bit, TCRE, enables channel 7 output compares to reset the timer counter. A
channel 7 output compare can reset the timer counter even if the IOC7 pin is being used as the pulse
accumulator input.
Writing to the timer port bit of an output compare pin does not affect the pin state. The value written is
stored in an internal latch. When the pin becomes available for general-purpose output, the last value
written to the bit appears at the pin.
When TCRE is set and TC7 is not equal to 0, then TCNT will cycle from 0 to TC7. When TCNT reaches
TC7 value, it will last only one bus cycle then reset to 0.
Chapter 15 Timer Module (TIM16B8CV1) Block Description
460 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Note: in Figure 15-29,if PR[2:0] is equal to 0, one prescaler counter equal to one bus clock
Figure 15-29. The TCNT cycle diagram under TCRE=1 condition
15.4.4 Pulse Accumulator
The pulse accumulator (PACNT) is a 16-bit counter that can operate in two modes:
Event counter mode — Counting edges of selected polarity on the pulse accumulator input pin, PAI.
Gated time accumulation mode — Counting pulses from a divide-by-64 clock. The PAMOD bit selects the
mode of operation.
The minimum pulse width for the PAI input is greater than two bus clocks.
15.4.5 Event Counter Mode
Clearing the PAMOD bit configures the PACNT for event counter operation. An active edge on the IOC7
pin increments the pulse accumulator counter. The PEDGE bit selects falling edges or rising edges to
increment the count.
NOTE
The PACNT input and timer channel 7 use the same pin IOC7. To use the
IOC7, disconnect it from the output logic by clearing the channel 7 output
mode and output level bits, OM7 and OL7. Also clear the channel 7 output
compare 7 mask bit, OC7M7.
The Pulse Accumulator counter register reflect the number of active input edges on the PACNT input pin
since the last reset.
The PAOVF bit is set when the accumulator rolls over from 0xFFFF to 0x0000. The pulse accumulator
overflow interrupt enable bit, PAOVI, enables the PAOVF flag to generate interrupt requests.
NOTE
The pulse accumulator counter can operate in event counter mode even
when the timer enable bit, TEN, is clear.
TC7 01----- TC7-1 TC7 0
TC7 event TC7 event
prescaler
counter 1 bus
clock
Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 461
Rev 01.24
15.4.6 Gated Time Accumulation Mode
Setting the PAMOD bit configures the pulse accumulator for gated time accumulation operation. An active
level on the PACNT input pin enables a divided-by-64 clock to drive the pulse accumulator. The PEDGE
bit selects low levels or high levels to enable the divided-by-64 clock.
The trailing edge of the active level at the IOC7 pin sets the PAIF. The PAI bit enables the PAIF flag to
generate interrupt requests.
The pulse accumulator counter register reflect the number of pulses from the divided-by-64 clock since the
last reset.
NOTE
The timer prescaler generates the divided-by-64 clock. If the timer is not
active, there is no divided-by-64 clock.
15.5 Resets
The reset state of each individual bit is listed within Section 15.3, “Memory Map and Register Definition”
which details the registers and their bit fields.
15.6 Interrupts
This section describes interrupts originated by the TIM16B8CV1 block. Table 15-23 lists the interrupts
generated by the TIM16B8CV1 to communicate with the MCU.
The TIM16B8CV1 uses a total of 11 interrupt vectors. The interrupt vector offsets and interrupt numbers
are chip dependent.
15.6.1 Channel [7:0] Interrupt (C[7:0]F)
This active high outputs will be asserted by the module to request a timer channel 7 – 0 interrupt to be
serviced by the system controller.
Table 15-23. TIM16B8CV1 Interrupts
Interrupt Offset
(1)
1. Chip Dependent.
Vector1Priority1Source Description
C[7:0]F — — — Timer Channel 7–0 Active high timer channel interrupts 7–0
PAOVI — — — Pulse Accumulator
Input
Active high pulse accumulator input interrupt
PAOVF — — — Pulse Accumulator
Overflow
Pulse accumulator overflow interrupt
TOF — — — Timer Overflow Timer Overflow interrupt
Chapter 15 Timer Module (TIM16B8CV1) Block Description
462 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
15.6.2 Pulse Accumulator Input Interrupt (PAOVI)
This active high output will be asserted by the module to request a timer pulse accumulator input interrupt
to be serviced by the system controller.
15.6.3 Pulse Accumulator Overflow Interrupt (PAOVF)
This active high output will be asserted by the module to request a timer pulse accumulator overflow
interrupt to be serviced by the system controller.
15.6.4 Timer Overflow Interrupt (TOF)
This active high output will be asserted by the module to request a timer overflow interrupt to be serviced
by the system controller.
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 463
Rev 01.24
Chapter 16
Dual Output Voltage Regulator (VREG3V3V2)
Block Description
16.1 Introduction
The VREG3V3V2 is a dual output voltage regulator providing two separate 2.5 V (typical) supplies
differing in the amount of current that can be sourced. The regulator input voltage range is from 3.3 V up
to 5 V (typical).
16.1.1 Features
The block VREG3V3V2 includes these distinctive features:
• Two parallel, linear voltage regulators
— Bandgap reference
• Low-voltage detect (LVD) with low-voltage interrupt (LVI)
• Power-on reset (POR)
• Low-voltage reset (LVR)
16.1.2 Modes of Operation
There are three modes VREG3V3V2 can operate in:
• Full-performance mode (FPM) (MCU is not in stop mode)
The regulator is active, providing the nominal supply voltage of 2.5 V with full current sourcing
capability at both outputs. Features LVD (low-voltage detect), LVR (low-voltage reset), and POR
(power-on reset) are available.
• Reduced-power mode (RPM) (MCU is in stop mode)
The purpose is to reduce power consumption of the device. The output voltage may degrade to a
lower value than in full-performance mode, additionally the current sourcing capability is
substantially reduced. Only the POR is available in this mode, LVD and LVR are disabled.
• Shutdown mode
Controlled by VREGEN (see device overview chapter for connectivity of VREGEN).
This mode is characterized by minimum power consumption. The regulator outputs are in a high
impedance state, only the POR feature is available, LVD and LVR are disabled.
This mode must be used to disable the chip internal regulator VREG3V3V2, i.e., to bypass the
VREG3V3V2 to use external supplies.
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) Block Description
464 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
16.1.3 Block Diagram
Figure 16-1 shows the function principle of VREG3V3V2 by means of a block diagram. The regulator
core REG consists of two parallel sub-blocks, REG1 and REG2, providing two independent output
voltages.
Figure 16-1. VREG3V3 Block Diagram
LVR
LVD POR
VDDR
VDD
LVI
POR
LVR
CTRL
VSS
VDDPLL
VSSPLL
VREGEN
REG
REG2
REG1
PIN
VDDA
VSSA
REG: Regulator Core
LVD: Low Voltage Detect
CTRL: Regulator Control
LVR: Low Voltage Reset
POR: Power-on Reset
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 465
Rev 01.24
16.2 External Signal Description
Due to the nature of VREG3V3V2 being a voltage regulator providing the chip internal power supply
voltages most signals are power supply signals connected to pads.
Table 16-1 shows all signals of VREG3V3V2 associated with pins.
NOTE
Check device overview chapter for connectivity of the signals.
16.2.1 VDDR — Regulator Power Input
Signal VDDR is the power input of VREG3V3V2. All currents sourced into the regulator loads flow
through this pin. A chip external decoupling capacitor (100 nF...220 nF, X7R ceramic) between VDDR and
VSSR can smoothen ripple on VDDR.
For entering Shutdown Mode, pin VDDR should also be tied to ground on devices without a VREGEN pin.
16.2.2 VDDA, VSSA — Regulator Reference Supply
Signals VDDA/VSSA which are supposed to be relatively quiet are used to supply the analog parts of the
regulator. Internal precision reference circuits are supplied from these signals. A chip external decoupling
capacitor (100 nF...220 nF, X7R ceramic) between VDDA and VSSA can further improve the quality of this
supply.
Table 16-1. VREG3V3V2 — Signal Properties
Name Port Function Reset State Pull Up
VDDR — VREG3V3V2 power input (positive supply) — —
VDDA — VREG3V3V2 quiet input (positive supply) — —
VSSA — VREG3V3V2 quiet input (ground) — —
VDD — VREG3V3V2 primary output (positive supply) — —
VSS — VREG3V3V2 primary output (ground) — —
VDDPLL — VREG3V3V2 secondary output (positive supply) — —
VSSPLL — VREG3V3V2 secondary output (ground) — —
VREGEN (optional) — VREG3V3V2 (Optional) Regulator Enable — —
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) Block Description
466 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
16.2.3 VDD, VSS — Regulator Output1 (Core Logic)
Signals VDD/VSS are the primary outputs of VREG3V3V2 that provide the power supply for the core
logic. These signals are connected to device pins to allow external decoupling capacitors (100 nF...220 nF,
X7R ceramic).
In Shutdown Mode an external supply at VDD/VSS can replace the voltage regulator.
16.2.4 VDDPLL, VSSPLL — Regulator Output2 (PLL)
Signals VDDPLL/VSSPLL are the secondary outputs of VREG3V3V2 that provide the power supply for the
PLL and oscillator. These signals are connected to device pins to allow external decoupling capacitors
(100 nF...220 nF, X7R ceramic).
In Shutdown Mode an external supply at VDDPLL/VSSPLL can replace the voltage regulator.
16.2.5 VREGEN — Optional Regulator Enable
This optional signal is used to shutdown VREG3V3V2. In that case VDD/VSS and VDDPLL/VSSPLL must
be provided externally. Shutdown Mode is entered with VREGEN being low. If VREGEN is high, the
VREG3V3V2 is either in Full Performance Mode or in Reduced Power Mode.
For the connectivity of VREGEN see device overview chapter.
NOTE
Switching from FPM or RPM to shutdown of VREG3V3V2 and vice versa
is not supported while the MCU is powered.
16.3 Memory Map and Register Definition
This subsection provides a detailed description of all registers accessible in VREG3V3V2.
16.3.1 Module Memory Map
Figure 16-2 provides an overview of all used registers.
Table 16-2. VREG3V3V2 Memory Map
Address
Offset Use Access
0x0000 VREG3V3V2 Control Register (VREGCTRL) R/W
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 467
Rev 01.24
16.3.2 Register Descriptions
The following paragraphs describe, in address order, all the VREG3V3V2 registers and their individual
bits.
16.3.2.1 VREG3V3V2 — Control Register (VREGCTRL)
The VREGCTRL register allows to separately enable features of VREG3V3V2.
NOTE
On entering the Reduced Power Mode the LVIF is not cleared by the
VREG3V3V2.
16.4 Functional Description
Block VREG3V3V2 is a voltage regulator as depicted in Figure 16-1. The regulator functional elements
are the regulator core (REG), a low-voltage detect module (LVD), a power-on reset module (POR) and a
low-voltage reset module (LVR). There is also the regulator control block (CTRL) which represents the
interface to the digital core logic but also manages the operating modes of VREG3V3V2.
Module Base + 0x0000
76543210
R00000LVDS
LVIE LVIF
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 16-2. VREG3V3 — Control Register (VREGCTRL)
Table 16-3. MCCTL1 Field Descriptions
Field Description
2
LVDS
Low-Voltage Detect Status Bit — This read-only status bit reflects the input voltage. Writes have no effect.
0 Input voltage VDDA is above level VLVID or RPM or shutdown mode.
1 Input voltage VDDA is below level VLVIA and FPM.
1
LVIE
Low-Voltage Interrupt Enable Bit
0 Interrupt request is disabled.
1 Interrupt will be requested whenever LVIF is set.
0
LVIF
Low-Voltage Interrupt Flag — LVIF is set to 1 when LVDS status bit changes. This flag can only be cleared by
writing a 1. Writing a 0 has no effect. If enabled (LVIE = 1), LVIF causes an interrupt request.
0 No change in LVDS bit.
1 LVDS bit has changed.
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) Block Description
468 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
16.4.1 REG — Regulator Core
VREG3V3V2, respectively its regulator core has two parallel, independent regulation loops (REG1 and
REG2) that differ only in the amount of current that can be sourced to the connected loads. Therefore, only
REG1 providing the supply at VDD/VSS is explained. The principle is also valid for REG2.
The regulator is a linear series regulator with a bandgap reference in its Full Performance Mode and a
voltage clamp in Reduced Power Mode. All load currents flow from input VDDR to VSS or VSSPLL, the
reference circuits are connected to VDDA and VSSA.
16.4.2 Full-Performance Mode
In Full Performance Mode, a fraction of the output voltage (VDD) and the bandgap reference voltage are
fed to an operational amplifier. The amplified input voltage difference controls the gate of an output driver
which basically is a large NMOS transistor connected to the output.
16.4.3 Reduced-Power Mode
In Reduced Power Mode, the driver gate is connected to a buffered fraction of the input voltage (VDDR).
The operational amplifier and the bandgap are disabled to reduce power consumption.
16.4.4 LVD — Low-Voltage Detect
sub-block LVD is responsible for generating the low-voltage interrupt (LVI). LVD monitors the input
voltage (VDDA–VSSA) and continuously updates the status flag LVDS. Interrupt flag LVIF is set whenever
status flag LVDS changes its value. The LVD is available in FPM and is inactive in Reduced Power Mode
and Shutdown Mode.
16.4.5 POR — Power-On Reset
This functional block monitors output VDD. If VDD is below VPORD, signal POR is high, if it exceeds
VPORD, the signal goes low. The transition to low forces the CPU in the power-on sequence.
Due to its role during chip power-up this module must be active in all operating modes of VREG3V3V2.
16.4.6 LVR — Low-Voltage Reset
Block LVR monitors the primary output voltage VDD. If it drops below the assertion level (VLVRA) signal
LVR asserts and when rising above the deassertion level (VLVRD) signal LVR negates again. The LVR
function is available only in Full Performance Mode.
16.4.7 CTRL — Regulator Control
This part contains the register block of VREG3V3V2 and further digital functionality needed to control
the operating modes. CTRL also represents the interface to the digital core logic.
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 469
Rev 01.24
16.5 Resets
This subsection describes how VREG3V3V2 controls the reset of the MCU.The reset values of registers
and signals are provided in Section 16.3, “Memory Map and Register Definition”. Possible reset sources
are listed in Table 16-4.
16.5.1 Power-On Reset
During chip power-up the digital core may not work if its supply voltage VDD is below the POR
deassertion level (VPORD). Therefore, signal POR which forces the other blocks of the device into reset is
kept high until VDD exceeds VPORD. Then POR becomes low and the reset generator of the device
continues the start-up sequence. The power-on reset is active in all operation modes of VREG3V3V2.
16.5.2 Low-Voltage Reset
For details on low-voltage reset see Section 16.4.6, “LVR — Low-Voltage Reset”.
16.6 Interrupts
This subsection describes all interrupts originated by VREG3V3V2.
The interrupt vectors requested by VREG3V3V2 are listed in Table 16-5. Vector addresses and interrupt
priorities are defined at MCU level.
16.6.1 LVI — Low-Voltage Interrupt
In FPM VREG3V3V2 monitors the input voltage VDDA. Whenever VDDA drops below level VLVIA the
status bit LVDS is set to 1. Vice versa, LVDS is reset to 0 when VDDA rises above level VLVID. An
interrupt, indicated by flag LVIF = 1, is triggered by any change of the status bit LVDS if interrupt enable
bit LVIE = 1.
NOTE
On entering the Reduced Power Mode, the LVIF is not cleared by the
VREG3V3V2.
Table 16-4. VREG3V3V2 — Reset Sources
Reset Source Local Enable
Power-on reset Always active
Low-voltage reset Available only in Full Performance Mode
Table 16-5. VREG3V3V2 — Interrupt Vectors
Interrupt Source Local Enable
Low Voltage Interrupt (LVI) LVIE = 1; Available only in Full Performance Mode
Chapter 16 Dual Output Voltage Regulator (VREG3V3V2) Block Description
470 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 471
Rev 01.24
Chapter 17
16 Kbyte Flash Module (S12FTS16KV1)
17.1 Introduction
The FTS16K module implements a 16 Kbyte Flash (nonvolatile) memory. The Flash memory contains one
array of 16 Kbytes organized as 256 rows of 64 bytes with an erase sector size of eight rows (512 bytes).
The Flash array may be read as either bytes, aligned words, or misaligned words. Read access time is one
bus cycle for byte and aligned word, and two bus cycles for misaligned words.
The Flash array is ideal for program and data storage for single-supply applications allowing for field
reprogramming without requiring external voltage sources for program or erase. Program and erase
functions are controlled by a command driven interface. The Flash module supports both mass erase and
sector erase. An erased bit reads 1 and a programmed bit reads 0. The high voltage required to program
and erase is generated internally. It is not possible to read from a Flash array while it is being erased or
programmed.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
17.1.1 Glossary
Command Write Sequence — A three-step MCU instruction sequence to program, erase, or erase verify
the Flash array memory.
17.1.2 Features
•16 Kbytes of Flash memory comprised of one 16 Kbyte array divided into 32 sectors of 512 bytes
• Automated program and erase algorithm
• Interrupts on Flash command completion and command buffer empty
• Fast sector erase and word program operation
• 2-stage command pipeline for faster multi-word program times
• Flexible protection scheme to prevent accidental program or erase
• Single power supply for Flash program and erase operations
• Security feature to prevent unauthorized access to the Flash array memory
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
472 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
17.1.3 Modes of Operation
See Section 17.4.2, “Operating Modes” for a description of the Flash module operating modes. For
program and erase operations, refer to Section 17.4.1, “Flash Command Operations”.
17.1.4 Block Diagram
Figure 17-1 shows a block diagram of the FTS16K module.
Figure 17-1. FTS16K Block Diagram
17.2 External Signal Description
The FTS16K module contains no signals that connect off-chip.
FTS16K
Oscillator
Clock
Command
Complete
Interrupt
Command
Buffer Empty
Interrupt
Flash Array
8K * 16 Bits
sector 0
sector 1
sector 31
Clock
Divider FCLK
Protection
Security
Command Pipeline
cmd2
addr2
data2
cmd1
addr1
data1
Registers
Flash
Interface
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 473
Rev 01.24
17.3 Memory Map and Registers
This section describes the FTS16K memory map and registers.
17.3.1 Module Memory Map
The FTS16K memory map is shown in Figure 17-2. The HCS12 architecture places the Flash array
addresses between 0xC000 and 0xFFFF. The content of the HCS12 Core PPAGE register is used to map
the logical page ranging from address 0x8000 to 0xBFFF to a physical 16K byte page in the Flash array
memory.1 The FPROT register (see Section 17.3.2.5) can be set to globally protect the entire Flash array
or one growing downward from the Flash array end address. The higher address area is mainly targeted to
hold the boot loader code since it covers the vector space. Default protection settings as well as security
information that allows the MCU to restrict access to the Flash module are stored in the Flash configuration
field described in Table 17-1.
1. By placing 0x3F in the HCS12 Core PPAGE register, the 16 Kbyte page can be seen twice in the MCU memory map.
Table 17-1. Flash Configuration Field
Flash Address Size
(bytes) Description
0xFF00–0xFF07 8 Backdoor Key to unlock security
0xFF08–0xFF0C 5 Reserved
0xFF0D 1 Flash Protection byte
Refer to Section 17.3.2.5, “Flash Protection Register (FPROT)”
0xFF0E 1 Reserved
0xFF0F 1 Flash Security/Options byte
Refer to Section 17.3.2.2, “Flash Security Register (FSEC)”
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
474 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 17-2. Flash Memory Map
Table 17-2. Flash Array Memory Map Summary
MCU Address
Range PPAGE Protectable
Address Range
0x8000–0xBFFF 0x3F 0xB800–0xBFFF
0xB000–0xBFFF
0xA000–0xBFFF
0x8000–0xBFFF
0xC000–0xFFFF Unpaged
(0x3F)
0xF800–0xFFFF
0xF000–0xFFFF
0xE000–0xFFFF
0xC000–0xFFFF
Flash Registers
MODULE BASE + 0x0000
0xFF00–0xFF0F (Flash Configuration Field)
MODULE BASE + 0x000F
0x8000
16K PAGED
MEMORY
0x3F
Note: 0x3F corresponds to the PPAGE register content
FLASH_END = 0xFFFF
0xF800
0xF000
FLASH_START = 0xC000
0xE000 Flash Protected High Sectors
2, 4, 8, 16 Kbytes
0x3F
16 bytes
Flash Array
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 475
Rev 01.24
17.3.2 Register Descriptions
The Flash module contains a set of 16 control and status registers located between module base + 0x0000
and 0x000F. A summary of the Flash module registers is given in Figure 17-3. Detailed descriptions of
each register bit are provided.
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000
FCLKDIV
R FDIVLD PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
0x0001
FSEC
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
0x0002
RESERVED1
(1)
1. Intended for factory test purposes only.
R00000000
W
0x0003
FCNFG
RCBEIE CCIE KEYACC 00000
W
0x0004
FPROT
RFPOPEN NV6 FPHDIS FPHS1 FPHS0 NV2 NV1 NV0
W
0x0005
FSTAT
RCBEIF CCIF PVIOL ACCERR 0 BLANK FAIL DONE
W
0x0006
FCMD
R0 CMDB6 CMDB5 00
CMDB2 0CMDB0
W
0x0007
RESERVED21
R00000000
W
0x0008
FADDRHI1
R 0 0 0 FABHI
W
0x0009
FADDRLO1
RFABLO
W
0x000A
FDATAHI1
RFDHI
W
0x000B
FDATALO1
RFDLO
W
0x000C
RESERVED31
R00000000
W
0x000D
RESERVED41
R00000000
W
0x000E
RESERVED51
R00000000
W
0x000F
RESERVED61
R00000000
W
= Unimplemented or Reserved
Figure 17-3. Flash Register Summary
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
476 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
17.3.2.1 Flash Clock Divider Register (FCLKDIV)
The FCLKDIV register is used to control timed events in program and erase algorithms.
All bits in the FCLKDIV register are readable, bits 6–0 are write once and bit 7 is not writable.
17.3.2.2 Flash Security Register (FSEC)
The FSEC register holds all bits associated with the security of the MCU and Flash module.
All bits in the FSEC register are readable but not writable.
The FSEC register is loaded from the Flash configuration field at 0xFF0F during the reset sequence,
indicated by F in Figure 17-5.
Module Base + 0x0000
76543210
R FDIVLD
PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-4. Flash Clock Divider Register (FCLKDIV)
Table 17-3. FCLKDIV Field Descriptions
Field Description
7
FDIVLD
Clock Divider Loaded
0 FCLKDIV register has not been written
1 FCLKDIV register has been written to since the last reset
6
PRDIV8
Enable Prescalar by 8
0 The oscillator clock is directly fed into the Flash clock divider
1 The oscillator clock is divided by 8 before feeding into the Flash clock divider
5–0
FDIV[5:0]
Clock Divider Bits — The combination of PRDIV8 and FDIV[5:0] must divide the oscillator clock down to a
frequency of 150 kHz – 200 kHz. The maximum divide ratio is 512. Refer to Section 17.4.1.1, “Writing the
FCLKDIV Register” for more information.
Module Base + 0x0001
76543210
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
Reset F F FFFFFF
= Unimplemented or Reserved
Figure 17-5. Flash Security Register (FSEC)
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 477
Rev 01.24
The security function in the Flash module is described in Section 17.4.3, “Flash Module Security”.
17.3.2.3 RESERVED1
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
Table 17-4. FSEC Field Descriptions
Field Description
7–6
KEYEN[1:0]
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of the backdoor key access
to the Flash module as shown in Table 17-5.
5–2
NV[5:2]
Nonvolatile Flag Bits — The NV[5:2] bits are available to the user as nonvolatile flags.
1–0
SEC[1:0]
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in Table 17-6. If the
Flash module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
Table 17-5. Flash KEYEN States
KEYEN[1:0] Status of Backdoor Key Access
00 DISABLED
01(1)
1. Preferred KEYEN state to disable Backdoor Key Access.
DISABLED
10 ENABLED
11 DISABLED
Table 17-6. Flash Security States
SEC[1:0] Status of Security
00 Secured
01(1)
1. Preferred SEC state to set MCU to secured state.
Secured
10 Unsecured
11 Secured
Module Base + 0x0002
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-6. RESERVED1
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
478 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
17.3.2.4 Flash Configuration Register (FCNFG)
The FCNFG register enables the Flash interrupts and gates the security backdoor key writes.
CBEIE, CCIE, and KEYACC are readable and writable while remaining bits read 0 and are not writable.
KEYACC is only writable if the KEYEN bit in the FSEC register is set to the enabled state (see Section
17.3.2.2).
17.3.2.5 Flash Protection Register (FPROT)
The FPROT register defines which Flash sectors are protected against program or erase.
The FPROT register is readable in normal and special modes. FPOPEN can only be written from a 1 to a 0.
FPHS[1:0] can be written anytime until FPHDIS is cleared. The FPROT register is loaded from Flash
address 0xFF0D during the reset sequence, indicated by F in Figure 17-8.
Module Base + 0x0003
76543210
R
CBEIE CCIE KEYACC
00000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-7. Flash Configuration Register (FCNFG)
Table 17-7. FCNFG Field Descriptions
Field Description
7
CBEIE
Command Buffer Empty Interrupt Enable — The CBEIE bit enables the interrupts in case of an empty
command buffer in the Flash module.
0 Command Buffer Empty interrupts disabled
1 An interrupt will be requested whenever the CBEIF flag is set (see Section 17.3.2.6)
6
CCIE
Command Complete Interrupt Enable — The CCIE bit enables the interrupts in case of all commands being
completed in the Flash module.
0 Command Complete interrupts disabled
1 An interrupt will be requested whenever the CCIF flag is set (see Section 17.3.2.6)
5
KEYACC
Enable Security Key Writing.
0 Flash writes are interpreted as the start of a command write sequence
1 Writes to the Flash array are interpreted as a backdoor key while reads of the Flash array return invalid data
Module Base + 0x0004
76543210
R
FPOPEN NV6 FPHDIS FPHS1 FPHS0 NV2 NV1 NV0
W
Reset F F FFFFFF
Figure 17-8. Flash Protection Register (FPROT)
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 479
Rev 01.24
To change the Flash protection that will be loaded on reset, the upper sector of the Flash array must be
unprotected, then the Flash protection byte located at Flash address 0xFF0D must be written to.
A protected Flash sector is disabled by FPHDIS while the size of the protected sector is defined by
FPHS[1:0] in the FPROT register.
Trying to alter any of the protected areas will result in a protect violation error and the PVIOL flag will be
set in the FSTAT register (see Section 17.3.2.6). A mass erase of the whole Flash array is only possible
when protection is fully disabled by setting the FPOPEN and FPHDIS bits. An attempt to mass erase a
Flash array while protection is enabled will set the PVIOL flag in the FSTAT register.
Table 17-8. FPROT Field Descriptions
Field Description
7
FPOPEN
Protection Function for Program or Erase — The FPOPEN bit is used to either select an address range to be
protected using the FPHDIS and FPHS[1:0] bits or to select the same address range to be unprotected as shown
in Table 17-9.
0 The FPHDIS bit allows a Flash address range to be unprotected
1 The FPHDIS bit allows a Flash address range to be protected
6
NV6
Nonvolatile Flag Bit — The NV6 bit should remain in the erased state for future enhancements.
5
FPHDIS
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in the higher space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
4–3
FPHS[1:0]
Flash Protection Higher Address Size — The FPHS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 17-10. The FPHS[1:0] bits can only be written to while the FPHDIS bit is set.
2–0
NV[2:0]
Nonvolatile Flag Bits — The NV[2:0] bits should remain in the erased state for future enhancements.
Table 17-9. Flash Protection Function
FPOPEN FPHDIS FPHS1 FPHS0 Function(1)
1. For range sizes refer to Table 17-10.
1 1 x x No protection
1 0 x x Protect high range
0 1 x x Full Flash array protected
0 0 x x Unprotected high range
Table 17-10. Flash Protection Higher Address Range
FPHS[1:0] Address Range Range Size
00 0xF800–0xFFFF 2 Kbytes
01 0xF000–0xFFFF 4 Kbytes
10 0xE000–0xFFFF 8 Kbytes
11 0xC000–0xFFFF 16 Kbytes
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
480 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 17-9 illustrates all possible protection scenarios. Although the protection scheme is loaded from the
Flash array after reset, it is allowed to change in normal modes. This protection scheme can be used by
applications requiring re-programming in single chip mode while providing as much protection as possible
if no re-programming is required.
Figure 17-9. Flash Protection Scenarios
17.3.2.5.1 Flash Protection Restrictions
The general guideline is that protection can only be added, not removed. All valid transitions between
Flash protection scenarios are specified in Table 17-11. Any attempt to write an invalid scenario to the
FPROT register will be ignored and the FPROT register will remain unchanged. The contents of the
FPROT register reflect the active protection scenario.
Table 17-11. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
0123
0XX
1X
2XX
3 2
FPHS[1:0]
FPOPEN = 1
1
FPOPEN = 0
FPHDIS = 1 FPHDIS = 0
Scenario
Scenario
Protected Flash
0
FPHS[1:0]
0xFFFF
0xFFFF
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 481
Rev 01.24
17.3.2.6 Flash Status Register (FSTAT)
The FSTAT register defines the status of the Flash command controller and the results of command
execution.
In normal modes, bits CBEIF, PVIOL, and ACCERR are readable and writable, bits CCIF and BLANK
are readable and not writable, remaining bits, including FAIL and DONE, read 0 and are not writable. In
special modes, FAIL is readable and writable while DONE is readable but not writable. FAIL must be clear
in special modes when starting a command write sequence.
3 XXXX
1. Allowed transitions marked with X.
Module Base + 0x0005
76543210
R
CBEIF
CCIF
PVIOL ACCERR
0 BLANK
FAIL
DONE
W
Reset 11000001
= Unimplemented or Reserved
Figure 17-10. Flash Status Register (FSTAT)
Table 17-12. FSTAT Field Descriptions
Field Description
7
CBEIF
Command Buffer Empty Interrupt Flag — The CBEIF flag indicates that the address, data and command
buffers are empty so that a new command write sequence can be started. The CBEIF flag is cleared by writing
a 1 to CBEIF. Writing a 0 to the CBEIF flag has no effect on CBEIF. Writing a 0 to CBEIF after writing an aligned
word to the Flash address space but before CBEIF is cleared will abort a command write sequence and cause
the ACCERR flag in the FSTAT register to be set. Writing a 0 to CBEIF outside of a command write sequence
will not set the ACCERR flag. The CBEIF flag is used together with the CBEIE bit in the FCNFG register to
generate an interrupt request (see Figure 17-26).
0 Buffers are full
1 Buffers are ready to accept a new command
6
CCIF
Command Complete Interrupt Flag — The CCIF flag indicates that there are no more commands pending. The
CCIF flag is cleared when CBEIF is clear and sets automatically upon completion of all active and pending
commands. The CCIF flag does not set when an active commands completes and a pending command is
fetched from the command buffer. Writing to the CCIF flag has no effect. The CCIF flag is used together with the
CCIE bit in the FCNFG register to generate an interrupt request (see Figure 17-26).
0 Command in progress
1 All commands are completed
Table 17-11. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
0123
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
482 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
17.3.2.7 Flash Command Register (FCMD)
The FCMD register defines the Flash commands.
Bits CMDB6, CMDB5, CMDB2, and CMDB0 are readable and writable during a command write
sequence while bits 7, 4, 3, and 1 read 0 and are not writable.
5
PVIOL
Protection Violation — The PVIOL flag indicates an attempt was made to program or erase an address in a
protected Flash array memory area. The PVIOL flag is cleared by writing a 1 to PVIOL. Writing a 0 to the PVIOL
flag has no effect on PVIOL. While PVIOL is set, it is not possible to launch another command.
0 No protection violation detected
1 Protection violation has occurred
4
ACCERR
Access Error — The ACCERR flag indicates an illegal access to the Flash array caused by either a violation of
the command write sequence, issuing an illegal command (illegal combination of the CMDBx bits in the FCMD
register) or the execution of a CPU STOP instruction while a command is executing (CCIF=0). The ACCERR flag
is cleared by writing a 1 to ACCERR. Writing a 0 to the ACCERR flag has no effect on ACCERR. While ACCERR
is set, it is not possible to launch another command.
0 No access error detected
1 Access error has occurred
2
BLANK
Flash Array Has Been Verified as Erased — The BLANK flag indicates that an erase verify command has
checked the Flash array and found it to be erased. The BLANK flag is cleared by hardware when CBEIF is
cleared as part of a new valid command write sequence. Writing to the BLANK flag has no effect on BLANK.
0 If an erase verify command has been requested, and the CCIF flag is set, then a 0 in BLANK indicates the
array is not erased
1 Flash array verifies as erased
1
FAIL
Flag Indicating a Failed Flash Operation — In special modes, the FAIL flag will set if the erase verify operation
fails (Flash array verified as not erased). Writing a 0 to the FAIL flag has no effect on FAIL. The FAIL flag is cleared
by writing a 1 to FAIL. While FAIL is set, it is not possible to launch another command.
0 Flash operation completed without error
1 Flash operation failed
0
DONE
Flag Indicating a Failed Operation is not Active — In special modes, the DONE flag will clear if a program,
erase, or erase verify operation is active.
0 Flash operation is active
1 Flash operation is not active
Module Base + 0x0006
76543210
R0
CMDB6 CMDB5
00
CMDB2
0
CMDB0
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-11. Flash Command Register (FCMD)
Table 17-12. FSTAT Field Descriptions
Field Description
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 483
Rev 01.24
17.3.2.8 RESERVED2
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
17.3.2.9 Flash Address Register (FADDR)
FADDRHI and FADDRLO are the Flash address registers.
\
Table 17-13. FCMD Field Descriptions
Field Description
6, 5, 2, 0
CMDB[6:5]
CMDB[2]
CMDB[0]
Valid Flash commands are shown in Table 17-14. An attempt to execute any command other than those listed in
Table 17-14 will set the ACCERR bit in the FSTAT register (see Section 17.3.2.6).
Table 17-14. Valid Flash Command List
CMDB NVM Command
0x05 Erase verify
0x20 Word program
0x40 Sector erase
0x41 Mass erase
Module Base + 0x0007
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-12. RESERVED2
Module Base + 0x0008
76543210
R000
FABHI
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-13. Flash Address High Register (FADDRHI)
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
484 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
In normal modes, all FABHI and FABLO bits read 0 and are not writable. In special modes, the FABHI
and FABLO bits are readable and writable. For sector erase, the MCU address bits [8:0] are ignored.For
mass erase, any address within the Flash array is valid to start the command.
17.3.2.10 Flash Data Register (FDATA)
FDATAHI and FDATALO are the Flash data registers.
In normal modes, all FDATAHI and FDATALO bits read 0 and are not writable. In special modes, all
FDATAHI and FDATALO bits are readable and writable when writing to an address within the Flash
address range.
17.3.2.11 RESERVED3
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x0009
76543210
R
FABLO
W
Reset 00000000
Figure 17-14. Flash Address Low Register (FADDRLO)
Module Base + 0x000A
76543210
R
FDHI
W
Reset 00000000
Figure 17-15. Flash Data High Register (FDATAHI)
Module Base + 0x000B
76543210
R
FDLO
W
Reset 00000000
Figure 17-16. Flash Data Low Register (FDATALO)
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 485
Rev 01.24
All bits read 0 and are not writable.
17.3.2.12 RESERVED4
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
17.3.2.13 RESERVED5
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
17.3.2.14 RESERVED6
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x000C
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-17. RESERVED3
Module Base + 0x000D
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-18. RESERVED4
Module Base + 0x000E
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-19. RESERVED5
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
486 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
All bits read 0 and are not writable.
17.4 Functional Description
17.4.1 Flash Command Operations
Write operations are used for the program, erase, and erase verify algorithms described in this section. The
program and erase algorithms are controlled by a state machine whose timebase FCLK is derived from the
oscillator clock via a programmable divider. The FCMD register as well as the associated FADDR and
FDATA registers operate as a buffer and a register (2-stage FIFO) so that a new command along with the
necessary data and address can be stored to the buffer while the previous command is still in progress. This
pipelined operation allows a time optimization when programming more than one word on a specific row,
as the high voltage generation can be kept active in between two programming commands. The pipelined
operation also allows a simplification of command launching. Buffer empty as well as command
completion are signalled by flags in the FSTAT register with corresponding interrupts generated, if
enabled.
The next sections describe:
• How to write the FCLKDIV register
• Command write sequence used to program, erase or erase verify the Flash array
• Valid Flash commands
• Errors resulting from illegal Flash operations
17.4.1.1 Writing the FCLKDIV Register
Prior to issuing any Flash command after a reset, it is first necessary to write the FCLKDIV register to
divide the oscillator clock down to within the 150-kHz to 200-kHz range. Since the program and erase
timings are also a function of the bus clock, the FCLKDIV determination must take this information into
account.
If we define:
• FCLK as the clock of the Flash timing control block
• Tbus as the period of the bus clock
• INT(x) as taking the integer part of x (e.g., INT(4.323) = 4),
Module Base + 0x000F
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-20. RESERVED6
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 487
Rev 01.24
then FCLKDIV register bits PRDIV8 and FDIV[5:0] are to be set as described in Figure 17-21.
For example, if the oscillator clock frequency is 950 kHz and the bus clock is 10 MHz, FCLKDIV bits
FDIV[5:0] should be set to 4 (000100) and bit PRDIV8 set to 0. The resulting FCLK is then 190 kHz. As
a result, the Flash algorithm timings are increased over optimum target by:
Command execution time will increase proportionally with the period of FCLK.
CAUTION
Because of the impact of clock synchronization on the accuracy of the
functional timings, programming or erasing the Flash array cannot be
performed if the bus clock runs at less than 1 MHz. Programming or erasing
the Flash array with an input clock < 150 kHz should be avoided. Setting
FCLKDIV to a value such that FCLK < 150 kHz can destroy the Flash array
due to overstress. Setting FCLKDIV to a value such that (1/FCLK + Tbus)
< 5µs can result in incomplete programming or erasure of the Flash array
cells.
If the FCLKDIV register is written, the bit FDIVLD is set automatically. If the FDIVLD bit is 0, the
FCLKDIV register has not been written since the last reset. If the FCLKDIV register has not been written
to, the Flash command loaded during a command write sequence will not execute and the ACCERR flag
in the FSTAT register will set.
200 190–()200⁄100×5%=
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
488 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 17-21. PRDIV8 and FDIV Bits Determination Procedure
PRDIV8=1
yes
no
PRDIV8=0 (reset)
12.8MHz?
FCLK=(PRDCLK)/(1+FDIV[5:0])
PRDCLK=oscillator_clock
PRDCLK=oscillator_clock/8
PRDCLK[MHz]*(5+Tbus[µs]) no
FDIV[5:0]=PRDCLK[MHz]*(5+Tbus[µs])-1
yes
START
Tbus < 1µs?
an integer?
FDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[µs]))
1/FCLK[MHz] + Tbus[µs] > 5
AND
FCLK > 0.15MHz
?
END
yes
no
FDIV[5:0] > 4?
ALL COMMANDS IMPOSSIBLE
yes
no
ALL COMMANDS IMPOSSIBLE
no
TRY TO DECREASE Tbus
yes
oscillator_clock
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 489
Rev 01.24
17.4.1.2 Command Write Sequence
The Flash command controller is used to supervise the command write sequence to execute program,
erase, and erase verify algorithms.
Before starting a command write sequence, the ACCERR and PVIOL flags in the FSTAT register must be
clear and the CBEIF flag should be tested to determine the state of the address, data, and command buffers.
If the CBEIF flag is set, indicating the buffers are empty, a new command write sequence can be started.
If the CBEIF flag is clear, indicating the buffers are not available, a new command write sequence will
overwrite the contents of the address, data, and command buffers.
A command write sequence consists of three steps which must be strictly adhered to with writes to the
Flash module not permitted between the steps. However, Flash register and array reads are allowed during
a command write sequence. The basic command write sequence is as follows:
1. Write to a valid address in the Flash array memory.
2. Write a valid command to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the command.
The address written in step 1 will be stored in the FADDR registers and the data will be stored in the
FDATA registers. When the CBEIF flag is cleared in step 3, the CCIF flag is cleared by the Flash command
controller indicating that the command was successfully launched. For all command write sequences, the
CBEIF flag will set after the CCIF flag is cleared indicating that the address, data, and command buffers
are ready for a new command write sequence to begin. A buffered command will wait for the active
operation to be completed before being launched. Once a command is launched, the completion of the
command operation is indicated by the setting of the CCIF flag in the FSTAT register. The CCIF flag will
set upon completion of all active and buffered commands.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
490 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
17.4.1.3 Valid Flash Commands
Table 17-15 summarizes the valid Flash commands along with the effects of the commands on the Flash
array.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
Table 17-15. Valid Flash Commands
FCMD Meaning Function on Flash Array
0x05 Erase
Verify
Verify all bytes in the Flash array are erased.
If the Flash array is erased, the BLANK bit will set in the FSTAT register upon command completion.
0x20 Program Program a word (2 bytes) in the Flash array.
0x40 Sector
Erase
Erase all 512 bytes in a sector of the Flash array.
0x41 Mass
Erase
Erase all bytes in the Flash array.
A mass erase of the full Flash array is only possible when FPHDIS and FPOPEN bits in the FPROT
register are set prior to launching the command.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 491
Rev 01.24
17.4.1.3.1 Erase Verify Command
The erase verify operation will verify that a Flash array is erased.
An example flow to execute the erase verify operation is shown in Figure 17-22. The erase verify command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the erase verify command.
The address and data written will be ignored.
2. Write the erase verify command, 0x05, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the erase verify
command.
After launching the erase verify command, the CCIF flag in the FSTAT register will set after the operation
has completed unless a new command write sequence has been buffered. Upon completion of the erase
verify operation, the BLANK flag in the FSTAT register will be set if all addresses in the Flash array are
verified to be erased. If any address in the Flash array is not erased, the erase verify operation will terminate
and the BLANK flag in the FSTAT register will remain clear.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
492 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 17-22. Example Erase Verify Command Flow
Write: Flash Array Address
Write: FCMD register
Erase Verify Command 0x05
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and Dummy Data
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CCIF
Set?
ACCERR/
PVIOL
Set?
no
Erase Verify
Status
yes
EXIT
Flash Array
Not Erased
EXIT
Flash Array
Erased
BLANK
Set?
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 493
Rev 01.24
17.4.1.3.2 Program Command
The program operation will program a previously erased word in the Flash array using an embedded
algorithm.
An example flow to execute the program operation is shown in Figure 17-23. The program command write
sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the program command. The
data written will be programmed to the Flash array address written.
2. Write the program command, 0x20, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the program
command.
If a word to be programmed is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the program command will not launch. Once the program command has successfully launched,
the CCIF flag in the FSTAT register will set after the program operation has completed unless a new
command write sequence has been buffered. By executing a new program command write sequence on
sequential words after the CBEIF flag in the FSTAT register has been set, up to 55% faster programming
time per word can be effectively achieved than by waiting for the CCIF flag to set after each program
operation.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
494 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 17-23. Example Program Command Flow
Write: Flash Address
Write: FCMD register
Program Command 0x20
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and program Data
Bit Polling for
Buffer Empty
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
yes
Sequential
Programming
Decision
Next
Word?
no
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
CCIF
Set?
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 495
Rev 01.24
17.4.1.3.3 Sector Erase Command
The sector erase operation will erase all addresses in a 512 byte sector of the Flash array using an
embedded algorithm.
An example flow to execute the sector erase operation is shown in Figure 17-24. The sector erase
command write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the sector erase command.
The Flash address written determines the sector to be erased while MCU address bits [8:0] and the
data written are ignored.
2. Write the sector erase command, 0x40, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the sector erase
command.
If a Flash sector to be erased is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the sector erase command will not launch. Once the sector erase command has successfully
launched, the CCIF flag in the FSTAT register will set after the sector erase operation has completed unless
a new command write sequence has been buffered.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
496 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 17-24. Example Sector Erase Command Flow
Write: Flash Sector Address
Write: FCMD register
Sector Erase Command 0x40
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 497
Rev 01.24
17.4.1.3.4 Mass Erase Command
The mass erase operation will erase all addresses in a Flash array using an embedded algorithm.
An example flow to execute the mass erase operation is shown in Figure 17-25. The mass erase command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the mass erase command.
The address and data written will be ignored.
2. Write the mass erase command, 0x41, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the mass erase
command.
If a Flash array to be erased contains any protected area, the PVIOL flag in the FSTAT register will set and
the mass erase command will not launch. Once the mass erase command has successfully launched, the
CCIF flag in the FSTAT register will set after the mass erase operation has completed unless a new
command write sequence has been buffered.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
498 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 17-25. Example Mass Erase Command Flow
Write: Flash Block Address
Write: FCMD register
Mass Erase Command 0x41
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 499
Rev 01.24
17.4.1.4 Illegal Flash Operations
17.4.1.4.1 Access Error
The ACCERR flag in the FSTAT register will be set during the command write sequence if any of the
following illegal Flash operations are performed causing the command write sequence to immediately
abort:
1. Writing to the Flash address space before initializing the FCLKDIV register
2. Writing a misaligned word or a byte to the valid Flash address space
3. Writing to the Flash address space while CBEIF is not set
4. Writing a second word to the Flash address space before executing a program or erase command
on the previously written word
5. Writing to any Flash register other than FCMD after writing a word to the Flash address space
6. Writing a second command to the FCMD register before executing the previously written
command
7. Writing an invalid command to the FCMD register
8. Writing to any Flash register other than FSTAT (to clear CBEIF) after writing to the FCMD register
9. The part enters stop mode and a program or erase command is in progress. The command is aborted
and any pending command is killed
10. When security is enabled, a command other than mass erase originating from a non-secure memory
or from the background debug mode is written to the FCMD register
11. A 0 is written to the CBEIF bit in the FSTAT register to abort a command write sequence.
The ACCERR flag will not be set if any Flash register is read during the command write sequence. If the
Flash array is read during execution of an algorithm (CCIF=0), the Flash module will return invalid data
and the ACCERR flag will not be set. If an ACCERR flag is set in the FSTAT register, the Flash command
controller is locked. It is not possible to launch another command until the ACCERR flag is cleared.
17.4.1.4.2 Protection Violation
The PVIOL flag in the FSTAT register will be set during the command write sequence after the word write
to the Flash address space if any of the following illegal Flash operations are performed, causing the
command write sequence to immediately abort:
1. Writing a Flash address to program in a protected area of the Flash array (see Section 17.3.2.5).
2. Writing a Flash address to erase in a protected area of the Flash array.
3. Writing the mass erase command to the FCMD register while any protection is enabled.
If the PVIOL flag is set, the Flash command controller is locked. It is not possible to launch another
command until the PVIOL flag is cleared.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
500 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
17.4.2 Operating Modes
17.4.2.1 Wait Mode
If the MCU enters wait mode while a Flash command is active (CCIF = 0), that command and any buffered
command will be completed.
The Flash module can recover the MCU from wait mode if the interrupts are enabled (see Section 17.4.5).
17.4.2.2 Stop Mode
If the MCU enters stop mode while a Flash command is active (CCIF = 0), that command will be aborted
and the data being programmed or erased is lost. The high voltage circuitry to the Flash array will be
switched off when entering stop mode. CCIF and ACCERR flags will be set. Upon exit from stop mode,
the CBEIF flag will be set and any buffered command will not be executed. The ACCERR flag must be
cleared before returning to normal operation.
NOTE
As active Flash commands are immediately aborted when the MCU enters
stop mode, it is strongly recommended that the user does not use the STOP
instruction during program and erase execution.
17.4.2.3 Background Debug Mode
In background debug mode (BDM), the FPROT register is writable. If the MCU is unsecured, then all
Flash commands listed in Table 17-15 can be executed. If the MCU is secured and is in special single chip
mode, the only possible command to execute is mass erase.
17.4.3 Flash Module Security
The Flash module provides the necessary security information to the MCU. After each reset, the Flash
module determines the security state of the MCU as defined in Section 17.3.2.2, “Flash Security Register
(FSEC)”.
The contents of the Flash security/options byte at address 0xFF0F in the Flash configuration field must be
changed directly by programming address 0xFF0F when the device is unsecured and the higher address
sector is unprotected. If the Flash security/options byte is left in the secure state, any reset will cause the
MCU to return to the secure operating mode.
17.4.3.1 Unsecuring the MCU using Backdoor Key Access
The MCU may only be unsecured by using the backdoor key access feature which requires knowledge of
the contents of the backdoor key (four 16-bit words programmed at addresses 0xFF00–0xFF07). If
KEYEN[1:0] = 1:0 and the KEYACC bit is set, a write to a backdoor key address in the Flash array triggers
a comparison between the written data and the backdoor key data stored in the Flash array. If all four words
of data are written to the correct addresses in the correct order and the data matches the backdoor key
stored in the Flash array, the MCU will be unsecured. The data must be written to the backdoor key
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 501
Rev 01.24
addresses sequentially staring with 0xFF00-0xFF01 and ending with 0xFF06–0xFF07. The values 0x0000
and 0xFFFF are not permitted as keys. When the KEYACC bit is set, reads of the Flash array will return
invalid data.
The user code stored in the Flash array must have a method of receiving the backdoor key from an external
stimulus. This external stimulus would typically be through one of the on-chip serial ports.
If KEYEN[1:0] = 1:0 in the FSEC register, the MCU can be unsecured by the backdoor key access
sequence described below:
1. Set the KEYACC bit in the FCNFG register
2. Write the correct four 16-bit words to Flash addresses 0xFF00–0xFF07 sequentially starting with
0xFF00
3. Clear the KEYACC bit in the FCNFG register
4. If all four 16-bit words match the backdoor key stored in Flash addresses 0xFF00–0xFF07, the
MCU is unsecured and bits SEC[1:0] in the FSEC register are forced to the unsecure state of 1:0
The backdoor key access sequence is monitored by the internal security state machine. An illegal operation
during the backdoor key access sequence will cause the security state machine to lock, leaving the MCU
in the secured state. A reset of the MCU will cause the security state machine to exit the lock state and
allow a new backdoor key access sequence to be attempted. The following illegal operations will lock the
security state machine:
1. If any of the four 16-bit words does not match the backdoor key programmed in the Flash array
2. If the four 16-bit words are written in the wrong sequence
3. If more than four 16-bit words are written
4. If any of the four 16-bit words written are 0x0000 or 0xFFFF
5. If the KEYACC bit does not remain set while the four 16-bit words are written
After the backdoor key access sequence has been correctly matched, the MCU will be unsecured. The
Flash security byte can be programmed to the unsecure state, if desired.
In the unsecure state, the user has full control of the contents of the four word backdoor key by
programming bytes 0xFF00–0xFF07 of the Flash configuration field.
The security as defined in the Flash security/options byte at address 0xFF0F is not changed by using the
backdoor key access sequence to unsecure. The backdoor key stored in addresses 0xFF00–0xFF07 is
unaffected by the backdoor key access sequence. After the next reset sequence, the security state of the
Flash module is determined by the Flash security/options byte at address 0xFF0F. The backdoor key access
sequence has no effect on the program and erase protection defined in the FPROT register.
It is not possible to unsecure the MCU in special single chip mode by executing the backdoor key access
sequence in background debug mode.
Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
502 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
17.4.4 Flash Reset Sequence
On each reset, the Flash module executes a reset sequence to hold CPU activity while loading the following
registers from the Flash array memory according to Table 17-1:
• FPROT — Flash Protection Register (see Section 17.3.2.5)
• FSEC — Flash Security Register (see Section 17.3.2.2)
17.4.4.1 Reset While Flash Command Active
If a reset occurs while any Flash command is in progress, that command will be immediately aborted. The
state of the word being programmed or the sector/array being erased is not guaranteed.
17.4.5 Interrupts
The Flash module can generate an interrupt when all Flash commands have completed execution or the
Flash address, data, and command buffers are empty.
NOTE
Vector addresses and their relative interrupt priority are determined at the
MCU level.
17.4.5.1 Description of Interrupt Operation
Figure 17-26 shows the logic used for generating interrupts.
The Flash module uses the CBEIF and CCIF flags in combination with the enable bits CBIE and CCIE to
discriminate for the generation of interrupts.
Figure 17-26. Flash Interrupt Implementation
For a detailed description of these register bits, refer to Section 17.3.2.4, “Flash Configuration Register
(FCNFG)” and Section 17.3.2.6, “Flash Status Register (FSTAT)”.
Table 17-16. Flash Interrupt Sources
Interrupt Source Interrupt Flag Local Enable Global (CCR) Mask
Flash Address, Data, and Command
Buffers are empty
CBEIF
(FSTAT register)
CBEIE I Bit
All Flash commands have completed
execution
CCIF
(FSTAT register)
CCIE I Bit
CBEIF
CBEIE
CCIF
CCIE
FLASH INTERRUPT REQUEST
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 503
Rev 01.24
Chapter 18
32 Kbyte Flash Module (S12FTS32KV1)
18.1 Introduction
The FTS32K module implements a 32 Kbyte Flash (nonvolatile) memory. The Flash memory contains one
array of 32 Kbytes organized as 512 rows of 64 bytes with an erase sector size of eight rows (512 bytes).
The Flash array may be read as either bytes, aligned words, or misaligned words. Read access time is one
bus cycle for byte and aligned word, and two bus cycles for misaligned words.
The Flash array is ideal for program and data storage for single-supply applications allowing for field
reprogramming without requiring external voltage sources for program or erase. Program and erase
functions are controlled by a command driven interface. The Flash module supports both mass erase and
sector erase. An erased bit reads 1 and a programmed bit reads 0. The high voltage required to program
and erase is generated internally. It is not possible to read from a Flash array while it is being erased or
programmed.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
18.1.1 Glossary
Command Write Sequence — A three-step MCU instruction sequence to program, erase, or erase verify
the Flash array memory.
18.1.2 Features
•32 Kbytes of Flash memory comprised of one 32 Kbyte array divided into 64 sectors of 512 bytes
• Automated program and erase algorithm
• Interrupts on Flash command completion and command buffer empty
• Fast sector erase and word program operation
• 2-stage command pipeline for faster multi-word program times
• Flexible protection scheme to prevent accidental program or erase
• Single power supply for Flash program and erase operations
• Security feature to prevent unauthorized access to the Flash array memory
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
504 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
18.1.3 Modes of Operation
See Section 18.4.2, “Operating Modes” for a description of the Flash module operating modes. For
program and erase operations, refer to Section 18.4.1, “Flash Command Operations”.
18.1.4 Block Diagram
Figure 18-1 shows a block diagram of the FTS32K module.
Figure 18-1. FTS32K Block Diagram
18.2 External Signal Description
The FTS32K module contains no signals that connect off-chip.
FTS32K
Oscillator
Clock
Command
Complete
Interrupt
Command
Buffer Empty
Interrupt
Flash Array
16K * 16 Bits
sector 0
sector 1
sector 63
Clock
Divider FCLK
Protection
Security
Command Pipeline
cmd2
addr2
data2
cmd1
addr1
data1
Registers
Flash
Interface
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 505
Rev 01.24
18.3 Memory Map and Registers
This section describes the FTS32K memory map and registers.
18.3.1 Module Memory Map
The FTS32K memory map is shown in Figure 18-2. The HCS12 architecture places the Flash array
addresses between 0x4000 and 0xFFFF, which corresponds to three 16 Kbyte pages. The content of the
HCS12 Core PPAGE register is used to map the logical middle page ranging from address 0x8000 to
0xBFFF to any physical 16K byte page in the Flash array memory.1 The FPROT register (see Section
18.3.2.5) can be set to globally protect the entire Flash array. Three separate areas, one starting from the
Flash array starting address (called lower) towards higher addresses, one growing downward from the
Flash array end address (called higher), and the remaining addresses, can be activated for protection.The
Flash array addresses covered by these protectable regions are shown in Figure 18-2. The higher address
area is mainly targeted to hold the boot loader code since it covers the vector space. The lower address area
can be used for EEPROM emulation in an MCU without an EEPROM module since it can be left
unprotected while the remaining addresses are protected from program or erase. Default protection
settings as well as security information that allows the MCU to restrict access to the Flash module are
stored in the Flash configuration field described in Table 18-1.
1. By placing 0x3E/0x3F in the HCS12 Core PPAGE register, the bottom/top fixed 16 Kbyte pagescan be seen twice in the MCU
memory map.
Table 18-1. Flash Configuration Field
Flash Address Size
(bytes) Description
0xFF00–0xFF07 8 Backdoor Key to unlock security
0xFF08–0xFF0C 5 Reserved
0xFF0D 1 Flash Protection byte
Refer to Section 18.3.2.5, “Flash Protection Register (FPROT)”
0xFF0E 1 Reserved
0xFF0F 1 Flash Security/Options byte
Refer to Section 18.3.2.2, “Flash Security Register (FSEC)”
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
506 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 18-2. Flash Memory Map
Flash Registers
MODULE BASE + 0x0000
0xFF00–0xFF0F (Flash Configuration Field)
MODULE BASE + 0x000F
0x8000
Flash Protected Low Sectors
512 bytes, 1, 2, 4 Kbytes
FLASH_START = 0x4000
0x4800
0x4200
0x5000
16K PAGED
MEMORY
0x3E
003E 0x3F
Note: 0x3E–0x3F correspond to the PPAGE register content
FLASH_END = 0xFFFF
0xF800
0xF000
0xC000
0xE000 Flash Protected High Sectors
2, 4, 8, 16 Kbytes
0x3F
0x4400
Flash Array
16 bytes
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 507
Rev 01.24
Table 18-2. Flash Array Memory Map Summary
MCU Address
Range PPAGE Protectable
Low Range
Protectable
High Range
Array Relative
Address(1)
1. Inside Flash block.
0x4000–0x7FFF Unpaged
(0x3E)
0x4000–0x43FF N.A. 0x18000–0x1BFFF
0x4000–0x47FF
0x4000–0x4FFF
0x4000–0x5FFF
0x8000–0xBFFF 0x3E 0x8000–0x83FF N.A. 0x18000–0x1BFFF
0x8000–0x87FF
0x8000–0x8FFF
0x8000–0x9FFF
0x3F N.A. 0xB800–0xBFFF 0x1C000–0x1FFFF
0xB000–0xBFFF
0xA000–0xBFFF
0x8000–0xBFFF
0xC000–0xFFFF Unpaged
(0x3F)
N.A. 0xF800–0xFFFF 0x1C000–0x1FFFF
0xF000–0xFFFF
0xE000–0xFFFF
0xC000–0xFFFF
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
508 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
18.3.2 Register Descriptions
The Flash module contains a set of 16 control and status registers located between module base + 0x0000
and 0x000F. A summary of the Flash module registers is given in Figure 18-3. Detailed descriptions of
each register bit are provided.
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000
FCLKDIV
R FDIVLD PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
0x0001
FSEC
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
0x0002
RESERVED1
(1)
1. Intended for factory test purposes only.
R00000000
W
0x0003
FCNFG
RCBEIE CCIE KEYACC 00000
W
0x0004
FPROT
RFPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
0x0005
FSTAT
RCBEIF CCIF PVIOL ACCERR 0 BLANK FAIL DONE
W
0x0006
FCMD
R0 CMDB6 CMDB5 00
CMDB2 0CMDB0
W
0x0007
RESERVED21
R00000000
W
0x0008
FADDRHI1
R 0 0 FABHI
W
0x0009
FADDRLO1
RFABLO
W
0x000A
FDATAHI1
RFDHI
W
0x000B
FDATALO1
RFDLO
W
0x000C
RESERVED31
R00000000
W
0x000D
RESERVED41
R00000000
W
0x000E
RESERVED51
R00000000
W
0x000F
RESERVED61
R00000000
W
= Unimplemented or Reserved
Figure 18-3. Flash Register Summary
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 509
Rev 01.24
18.3.2.1 Flash Clock Divider Register (FCLKDIV)
The FCLKDIV register is used to control timed events in program and erase algorithms.
All bits in the FCLKDIV register are readable, bits 6–0 are write once and bit 7 is not writable.
18.3.2.2 Flash Security Register (FSEC)
The FSEC register holds all bits associated with the security of the MCU and Flash module.
All bits in the FSEC register are readable but not writable.
The FSEC register is loaded from the Flash configuration field at 0xFF0F during the reset sequence,
indicated by F in Figure 18-5.
Module Base + 0x0000
76543210
R FDIVLD
PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-4. Flash Clock Divider Register (FCLKDIV)
Table 18-3. FCLKDIV Field Descriptions
Field Description
7
FDIVLD
Clock Divider Loaded
0 FCLKDIV register has not been written
1 FCLKDIV register has been written to since the last reset
6
PRDIV8
Enable Prescalar by 8
0 The oscillator clock is directly fed into the Flash clock divider
1 The oscillator clock is divided by 8 before feeding into the Flash clock divider
5–0
FDIV[5:0]
Clock Divider Bits — The combination of PRDIV8 and FDIV[5:0] must divide the oscillator clock down to a
frequency of 150 kHz – 200 kHz. The maximum divide ratio is 512. Refer to Section 18.4.1.1, “Writing the
FCLKDIV Register” for more information.
Module Base + 0x0001
76543210
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
Reset F F FFFFFF
= Unimplemented or Reserved
Figure 18-5. Flash Security Register (FSEC)
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
510 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The security function in the Flash module is described in Section 18.4.3, “Flash Module Security”.
18.3.2.3 RESERVED1
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
Table 18-4. FSEC Field Descriptions
Field Description
7–6
KEYEN[1:0]
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of the backdoor key access
to the Flash module as shown in Table 18-5.
5–2
NV[5:2]
Nonvolatile Flag Bits — The NV[5:2] bits are available to the user as nonvolatile flags.
1–0
SEC[1:0]
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in Table 18-6. If the
Flash module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
Table 18-5. Flash KEYEN States
KEYEN[1:0] Status of Backdoor Key Access
00 DISABLED
01(1)
1. Preferred KEYEN state to disable Backdoor Key Access.
DISABLED
10 ENABLED
11 DISABLED
Table 18-6. Flash Security States
SEC[1:0] Status of Security
00 Secured
01(1)
1. Preferred SEC state to set MCU to secured state.
Secured
10 Unsecured
11 Secured
Module Base + 0x0002
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-6. RESERVED1
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 511
Rev 01.24
18.3.2.4 Flash Configuration Register (FCNFG)
The FCNFG register enables the Flash interrupts and gates the security backdoor key writes.
CBEIE, CCIE, and KEYACC are readable and writable while remaining bits read 0 and are not writable.
KEYACC is only writable if the KEYEN bit in the FSEC register is set to the enabled state (see Section
18.3.2.2).
18.3.2.5 Flash Protection Register (FPROT)
The FPROT register defines which Flash sectors are protected against program or erase.
The FPROT register is readable in normal and special modes. FPOPEN can only be written from a 1 to a 0.
FPLS[1:0] can be written anytime until FPLDIS is cleared. FPHS[1:0] can be written anytime until
Module Base + 0x0003
76543210
R
CBEIE CCIE KEYACC
00000
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-7. Flash Configuration Register (FCNFG)
Table 18-7. FCNFG Field Descriptions
Field Description
7
CBEIE
Command Buffer Empty Interrupt Enable — The CBEIE bit enables the interrupts in case of an empty
command buffer in the Flash module.
0 Command Buffer Empty interrupts disabled
1 An interrupt will be requested whenever the CBEIF flag is set (see Section 18.3.2.6)
6
CCIE
Command Complete Interrupt Enable — The CCIE bit enables the interrupts in case of all commands being
completed in the Flash module.
0 Command Complete interrupts disabled
1 An interrupt will be requested whenever the CCIF flag is set (see Section 18.3.2.6)
5
KEYACC
Enable Security Key Writing.
0 Flash writes are interpreted as the start of a command write sequence
1 Writes to the Flash array are interpreted as a backdoor key while reads of the Flash array return invalid data
Module Base + 0x0004
76543210
R
FPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
Reset F F FFFFFF
Figure 18-8. Flash Protection Register (FPROT)
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
512 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
FPHDIS is cleared. The FPROT register is loaded from Flash address 0xFF0D during the reset sequence,
indicated by F in Figure 18-8.
To change the Flash protection that will be loaded on reset, the upper sector of the Flash array must be
unprotected, then the Flash protection byte located at Flash address 0xFF0D must be written to.
A protected Flash sector is disabled by FPHDIS and FPLDIS while the size of the protected sector is
defined by FPHS[1:0] and FPLS[1:0] in the FPROT register.
Trying to alter any of the protected areas will result in a protect violation error and the PVIOL flag will be
set in the FSTAT register (see Section 18.3.2.6). A mass erase of the whole Flash array is only possible
when protection is fully disabled by setting the FPOPEN, FPLDIS, and FPHDIS bits. An attempt to mass
erase a Flash array while protection is enabled will set the PVIOL flag in the FSTAT register.
Table 18-8. FPROT Field Descriptions
Field Description
7
FPOPEN
Protection Function for Program or Erase — It is possible using the FPOPEN bit to either select address
ranges to be protected using FPHDIS, FPLDIS, FPHS[1:0] and FPLS[1:0] or to select the same ranges to be
unprotected. When FPOPEN is set, FPxDIS enables the ranges to be protected, whereby clearing FPxDIS
enables protection for the range specified by the corresponding FPxS[1:0] bits. When FPOPEN is cleared,
FPxDIS defines unprotected ranges as specified by the corresponding FPxS[1:0] bits. In this case, setting
FPxDIS enables protection. Thus the effective polarity of the FPxDIS bits is swapped by the FPOPEN bit as
shown in Table 18-9. This function allows the main part of the Flash array to be protected while a small range
can remain unprotected for EEPROM emulation.
0 The FPHDIS and FPLDIS bits define Flash address ranges to be unprotected
1 The FPHDIS and FPLDIS bits define Flash address ranges to be protected
6
NV6
Nonvolatile Flag Bit — The NV6 bit should remain in the erased state for future enhancements.
5
FPHDIS
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in the higher space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
4–3
FPHS[1:0]
Flash Protection Higher Address Size — The FPHS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 18-10. The FPHS[1:0] bits can only be written to while the FPHDIS bit is set.
2
FPLDIS
Flash Protection Lower Address Range Disable — The FPLDIS bit determines whether there is a
protected/unprotected sector in the lower space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
1–0
FPLS[1:0]
Flash Protection Lower Address Size — The FPLS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 18-11. The FPLS[1:0] bits can only be written to while the FPLDIS bit is set.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 513
Rev 01.24
Figure 18-9 illustrates all possible protection scenarios. Although the protection scheme is loaded from the
Flash array after reset, it is allowed to change in normal modes. This protection scheme can be used by
applications requiring re-programming in single chip mode while providing as much protection as possible
if no re-programming is required.
Table 18-9. Flash Protection Function
FPOPEN FPHDIS FPHS[1] FPHS[0] FPLDIS FPLS[1] FPLS[0] Function(1)
1. For range sizes refer to Table 18-10 and or Table 18-11.
1 1 x x 1 x x No protection
1 1 x x 0 x x Protect low range
1 0 x x 1 x x Protect high range
1 0 x x 0 x x Protect high and low ranges
0 1 x x 1 x x Full Flash array protected
0 0 x x 1 x x Unprotected high range
0 1 x x 0 x x Unprotected low range
0 0 x x 0 x x Unprotected high and low ranges
Table 18-10. Flash Protection Higher Address Range
FPHS[1:0] Address Range Range Size
00 0xF800–0xFFFF 2 Kbytes
01 0xF000–0xFFFF 4 Kbytes
10 0xE000–0xFFFF 8 Kbytes
11 0xC000–0xFFFF 16 Kbytes
Table 18-11. Flash Protection Lower Address Range
FPLS[1:0] Address Range Range Size
00 0x4000–0x41FF 512 bytes
01 0x4000–0x43FF 1 Kbyte
10 0x4000–0x47FF 2 Kbytes
11 0x4000–0x4FFF 4 Kbytes
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
514 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 18-9. Flash Protection Scenarios
18.3.2.5.1 Flash Protection Restrictions
The general guideline is that protection can only be added, not removed. All valid transitions between
Flash protection scenarios are specified in Table 18-12. Any attempt to write an invalid scenario to the
FPROT register will be ignored and the FPROT register will remain unchanged. The contents of the
FPROT register reflect the active protection scenario.
Table 18-12. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
0 XXXX
1XX
2XX
3X
4XX
5 XXXX
7654
FPOPEN = 1
3210
FPHS[1:0] FPLS[1:0]
FPOPEN = 0
FPHDIS = 1
FPLDIS = 1
FPHDIS = 1
FPLDIS = 0
FPHDIS = 0
FPLDIS = 1
FPHDIS = 0
FPLDIS = 0
Scenario
Scenario
Protected Flash
FPHS[1:0] FPLS[1:0]
0xFFFF
0xFFFF
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 515
Rev 01.24
18.3.2.6 Flash Status Register (FSTAT)
The FSTAT register defines the status of the Flash command controller and the results of command
execution.
In normal modes, bits CBEIF, PVIOL, and ACCERR are readable and writable, bits CCIF and BLANK
are readable and not writable, remaining bits, including FAIL and DONE, read 0 and are not writable. In
special modes, FAIL is readable and writable while DONE is readable but not writable. FAIL must be clear
in special modes when starting a command write sequence.
6XXXX
7 XXXXXXXX
1. Allowed transitions marked with X.
Module Base + 0x0005
76543210
R
CBEIF
CCIF
PVIOL ACCERR
0 BLANK
FAIL
DONE
W
Reset 11000001
= Unimplemented or Reserved
Figure 18-10. Flash Status Register (FSTAT)
Table 18-13. FSTAT Field Descriptions
Field Description
7
CBEIF
Command Buffer Empty Interrupt Flag — The CBEIF flag indicates that the address, data and command
buffers are empty so that a new command write sequence can be started. The CBEIF flag is cleared by writing
a 1 to CBEIF. Writing a 0 to the CBEIF flag has no effect on CBEIF. Writing a 0 to CBEIF after writing an aligned
word to the Flash address space but before CBEIF is cleared will abort a command write sequence and cause
the ACCERR flag in the FSTAT register to be set. Writing a 0 to CBEIF outside of a command write sequence
will not set the ACCERR flag. The CBEIF flag is used together with the CBEIE bit in the FCNFG register to
generate an interrupt request (see Figure 18-26).
0 Buffers are full
1 Buffers are ready to accept a new command
6
CCIF
Command Complete Interrupt Flag — The CCIF flag indicates that there are no more commands pending. The
CCIF flag is cleared when CBEIF is clear and sets automatically upon completion of all active and pending
commands. The CCIF flag does not set when an active commands completes and a pending command is
fetched from the command buffer. Writing to the CCIF flag has no effect. The CCIF flag is used together with the
CCIE bit in the FCNFG register to generate an interrupt request (see Figure 18-26).
0 Command in progress
1 All commands are completed
Table 18-12. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
516 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
18.3.2.7 Flash Command Register (FCMD)
The FCMD register defines the Flash commands.
Bits CMDB6, CMDB5, CMDB2, and CMDB0 are readable and writable during a command write
sequence while bits 7, 4, 3, and 1 read 0 and are not writable.
5
PVIOL
Protection Violation — The PVIOL flag indicates an attempt was made to program or erase an address in a
protected Flash array memory area. The PVIOL flag is cleared by writing a 1 to PVIOL. Writing a 0 to the PVIOL
flag has no effect on PVIOL. While PVIOL is set, it is not possible to launch another command.
0 No protection violation detected
1 Protection violation has occurred
4
ACCERR
Access Error — The ACCERR flag indicates an illegal access to the Flash array caused by either a violation of
the command write sequence, issuing an illegal command (illegal combination of the CMDBx bits in the FCMD
register) or the execution of a CPU STOP instruction while a command is executing (CCIF=0). The ACCERR flag
is cleared by writing a 1 to ACCERR. Writing a 0 to the ACCERR flag has no effect on ACCERR. While ACCERR
is set, it is not possible to launch another command.
0 No access error detected
1 Access error has occurred
2
BLANK
Flash Array Has Been Verified as Erased — The BLANK flag indicates that an erase verify command has
checked the Flash array and found it to be erased. The BLANK flag is cleared by hardware when CBEIF is
cleared as part of a new valid command write sequence. Writing to the BLANK flag has no effect on BLANK.
0 If an erase verify command has been requested, and the CCIF flag is set, then a 0 in BLANK indicates the
array is not erased
1 Flash array verifies as erased
1
FAIL
Flag Indicating a Failed Flash Operation — In special modes, the FAIL flag will set if the erase verify operation
fails (Flash array verified as not erased). Writing a 0 to the FAIL flag has no effect on FAIL. The FAIL flag is cleared
by writing a 1 to FAIL. While FAIL is set, it is not possible to launch another command.
0 Flash operation completed without error
1 Flash operation failed
0
DONE
Flag Indicating a Failed Operation is not Active — In special modes, the DONE flag will clear if a program,
erase, or erase verify operation is active.
0 Flash operation is active
1 Flash operation is not active
Module Base + 0x0006
76543210
R0
CMDB6 CMDB5
00
CMDB2
0
CMDB0
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-11. Flash Command Register (FCMD)
Table 18-13. FSTAT Field Descriptions
Field Description
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 517
Rev 01.24
18.3.2.8 RESERVED2
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
18.3.2.9 Flash Address Register (FADDR)
FADDRHI and FADDRLO are the Flash address registers.
\
Table 18-14. FCMD Field Descriptions
Field Description
6, 5, 2, 0
CMDB[6:5]
CMDB[2]
CMDB[0]
Valid Flash commands are shown in Table 18-15. An attempt to execute any command other than those listed in
Table 18-15 will set the ACCERR bit in the FSTAT register (see Section 18.3.2.6).
Table 18-15. Valid Flash Command List
CMDB NVM Command
0x05 Erase verify
0x20 Word program
0x40 Sector erase
0x41 Mass erase
Module Base + 0x0007
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-12. RESERVED2
Module Base + 0x0008
76543210
R0 0
FABHI
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-13. Flash Address High Register (FADDRHI)
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
518 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
In normal modes, all FABHI and FABLO bits read 0 and are not writable. In special modes, the FABHI
and FABLO bits are readable and writable. For sector erase, the MCU address bits [8:0] are ignored.For
mass erase, any address within the Flash array is valid to start the command.
18.3.2.10 Flash Data Register (FDATA)
FDATAHI and FDATALO are the Flash data registers.
In normal modes, all FDATAHI and FDATALO bits read 0 and are not writable. In special modes, all
FDATAHI and FDATALO bits are readable and writable when writing to an address within the Flash
address range.
18.3.2.11 RESERVED3
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x0009
76543210
R
FABLO
W
Reset 00000000
Figure 18-14. Flash Address Low Register (FADDRLO)
Module Base + 0x000A
76543210
R
FDHI
W
Reset 00000000
Figure 18-15. Flash Data High Register (FDATAHI)
Module Base + 0x000B
76543210
R
FDLO
W
Reset 00000000
Figure 18-16. Flash Data Low Register (FDATALO)
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 519
Rev 01.24
All bits read 0 and are not writable.
18.3.2.12 RESERVED4
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
18.3.2.13 RESERVED5
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
18.3.2.14 RESERVED6
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x000C
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-17. RESERVED3
Module Base + 0x000D
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-18. RESERVED4
Module Base + 0x000E
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-19. RESERVED5
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
520 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
All bits read 0 and are not writable.
18.4 Functional Description
18.4.1 Flash Command Operations
Write operations are used for the program, erase, and erase verify algorithms described in this section. The
program and erase algorithms are controlled by a state machine whose timebase FCLK is derived from the
oscillator clock via a programmable divider. The FCMD register as well as the associated FADDR and
FDATA registers operate as a buffer and a register (2-stage FIFO) so that a new command along with the
necessary data and address can be stored to the buffer while the previous command is still in progress. This
pipelined operation allows a time optimization when programming more than one word on a specific row,
as the high voltage generation can be kept active in between two programming commands. The pipelined
operation also allows a simplification of command launching. Buffer empty as well as command
completion are signalled by flags in the FSTAT register with corresponding interrupts generated, if
enabled.
The next sections describe:
• How to write the FCLKDIV register
• Command write sequence used to program, erase or erase verify the Flash array
• Valid Flash commands
• Errors resulting from illegal Flash operations
18.4.1.1 Writing the FCLKDIV Register
Prior to issuing any Flash command after a reset, it is first necessary to write the FCLKDIV register to
divide the oscillator clock down to within the 150-kHz to 200-kHz range. Since the program and erase
timings are also a function of the bus clock, the FCLKDIV determination must take this information into
account.
If we define:
• FCLK as the clock of the Flash timing control block
• Tbus as the period of the bus clock
• INT(x) as taking the integer part of x (e.g., INT(4.323) = 4),
Module Base + 0x000F
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 18-20. RESERVED6
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 521
Rev 01.24
then FCLKDIV register bits PRDIV8 and FDIV[5:0] are to be set as described in Figure 18-21.
For example, if the oscillator clock frequency is 950 kHz and the bus clock is 10 MHz, FCLKDIV bits
FDIV[5:0] should be set to 4 (000100) and bit PRDIV8 set to 0. The resulting FCLK is then 190 kHz. As
a result, the Flash algorithm timings are increased over optimum target by:
Command execution time will increase proportionally with the period of FCLK.
CAUTION
Because of the impact of clock synchronization on the accuracy of the
functional timings, programming or erasing the Flash array cannot be
performed if the bus clock runs at less than 1 MHz. Programming or erasing
the Flash array with an input clock < 150 kHz should be avoided. Setting
FCLKDIV to a value such that FCLK < 150 kHz can destroy the Flash array
due to overstress. Setting FCLKDIV to a value such that (1/FCLK + Tbus)
< 5µs can result in incomplete programming or erasure of the Flash array
cells.
If the FCLKDIV register is written, the bit FDIVLD is set automatically. If the FDIVLD bit is 0, the
FCLKDIV register has not been written since the last reset. If the FCLKDIV register has not been written
to, the Flash command loaded during a command write sequence will not execute and the ACCERR flag
in the FSTAT register will set.
200 190–()200⁄100×5%=
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
522 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 18-21. PRDIV8 and FDIV Bits Determination Procedure
PRDIV8=1
yes
no
PRDIV8=0 (reset)
12.8MHz?
FCLK=(PRDCLK)/(1+FDIV[5:0])
PRDCLK=oscillator_clock
PRDCLK=oscillator_clock/8
PRDCLK[MHz]*(5+Tbus[ms]) no
FDIV[5:0]=PRDCLK[MHz]*(5+Tbus[ms])-1
yes
START
Tbus < 1ms?
an integer?
FDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[ms]))
1/FCLK[MHz] + Tbus[ms] > 5
AND
FCLK > 0.15MHz
?
END
yes
no
FDIV[5:0] > 4?
ALL COMMANDS IMPOSSIBLE
yes
no
ALL COMMANDS IMPOSSIBLE
no
TRY TO DECREASE Tbus
yes
oscillator_clock
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 523
Rev 01.24
18.4.1.2 Command Write Sequence
The Flash command controller is used to supervise the command write sequence to execute program,
erase, and erase verify algorithms.
Before starting a command write sequence, the ACCERR and PVIOL flags in the FSTAT register must be
clear and the CBEIF flag should be tested to determine the state of the address, data, and command buffers.
If the CBEIF flag is set, indicating the buffers are empty, a new command write sequence can be started.
If the CBEIF flag is clear, indicating the buffers are not available, a new command write sequence will
overwrite the contents of the address, data, and command buffers.
A command write sequence consists of three steps which must be strictly adhered to with writes to the
Flash module not permitted between the steps. However, Flash register and array reads are allowed during
a command write sequence. The basic command write sequence is as follows:
1. Write to a valid address in the Flash array memory.
2. Write a valid command to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the command.
The address written in step 1 will be stored in the FADDR registers and the data will be stored in the
FDATA registers. When the CBEIF flag is cleared in step 3, the CCIF flag is cleared by the Flash command
controller indicating that the command was successfully launched. For all command write sequences, the
CBEIF flag will set after the CCIF flag is cleared indicating that the address, data, and command buffers
are ready for a new command write sequence to begin. A buffered command will wait for the active
operation to be completed before being launched. Once a command is launched, the completion of the
command operation is indicated by the setting of the CCIF flag in the FSTAT register. The CCIF flag will
set upon completion of all active and buffered commands.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
524 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
18.4.1.3 Valid Flash Commands
Table 18-16 summarizes the valid Flash commands along with the effects of the commands on the Flash
array.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
Table 18-16. Valid Flash Commands
FCMD Meaning Function on Flash Array
0x05 Erase
Verify
Verify all bytes in the Flash array are erased.
If the Flash array is erased, the BLANK bit will set in the FSTAT register upon command completion.
0x20 Program Program a word (2 bytes) in the Flash array.
0x40 Sector
Erase
Erase all 512 bytes in a sector of the Flash array.
0x41 Mass
Erase
Erase all bytes in the Flash array.
A mass erase of the full Flash array is only possible when FPLDIS, FPHDIS, and FPOPEN bits in
the FPROT register are set prior to launching the command.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 525
Rev 01.24
18.4.1.3.1 Erase Verify Command
The erase verify operation will verify that a Flash array is erased.
An example flow to execute the erase verify operation is shown in Figure 18-22. The erase verify command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the erase verify command.
The address and data written will be ignored.
2. Write the erase verify command, 0x05, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the erase verify
command.
After launching the erase verify command, the CCIF flag in the FSTAT register will set after the operation
has completed unless a new command write sequence has been buffered. Upon completion of the erase
verify operation, the BLANK flag in the FSTAT register will be set if all addresses in the Flash array are
verified to be erased. If any address in the Flash array is not erased, the erase verify operation will terminate
and the BLANK flag in the FSTAT register will remain clear.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
526 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 18-22. Example Erase Verify Command Flow
Write: Flash Array Address
Write: FCMD register
Erase Verify Command 0x05
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and Dummy Data
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CCIF
Set?
ACCERR/
PVIOL
Set?
no
Erase Verify
Status
yes
EXIT
Flash Array
Not Erased
EXIT
Flash Array
Erased
BLANK
Set?
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 527
Rev 01.24
18.4.1.3.2 Program Command
The program operation will program a previously erased word in the Flash array using an embedded
algorithm.
An example flow to execute the program operation is shown in Figure 18-23. The program command write
sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the program command. The
data written will be programmed to the Flash array address written.
2. Write the program command, 0x20, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the program
command.
If a word to be programmed is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the program command will not launch. Once the program command has successfully launched,
the CCIF flag in the FSTAT register will set after the program operation has completed unless a new
command write sequence has been buffered. By executing a new program command write sequence on
sequential words after the CBEIF flag in the FSTAT register has been set, up to 55% faster programming
time per word can be effectively achieved than by waiting for the CCIF flag to set after each program
operation.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
528 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 18-23. Example Program Command Flow
Write: Flash Address
Write: FCMD register
Program Command 0x20
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and program Data
Bit Polling for
Buffer Empty
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
yes
Sequential
Programming
Decision
Next
Word?
no
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
CCIF
Set?
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 529
Rev 01.24
18.4.1.3.3 Sector Erase Command
The sector erase operation will erase all addresses in a 512 byte sector of the Flash array using an
embedded algorithm.
An example flow to execute the sector erase operation is shown in Figure 18-24. The sector erase
command write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the sector erase command.
The Flash address written determines the sector to be erased while MCU address bits [8:0] and the
data written are ignored.
2. Write the sector erase command, 0x40, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the sector erase
command.
If a Flash sector to be erased is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the sector erase command will not launch. Once the sector erase command has successfully
launched, the CCIF flag in the FSTAT register will set after the sector erase operation has completed unless
a new command write sequence has been buffered.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
530 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 18-24. Example Sector Erase Command Flow
Write: Flash Sector Address
Write: FCMD register
Sector Erase Command 0x40
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 531
Rev 01.24
18.4.1.3.4 Mass Erase Command
The mass erase operation will erase all addresses in a Flash array using an embedded algorithm.
An example flow to execute the mass erase operation is shown in Figure 18-25. The mass erase command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the mass erase command.
The address and data written will be ignored.
2. Write the mass erase command, 0x41, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the mass erase
command.
If a Flash array to be erased contains any protected area, the PVIOL flag in the FSTAT register will set and
the mass erase command will not launch. Once the mass erase command has successfully launched, the
CCIF flag in the FSTAT register will set after the mass erase operation has completed unless a new
command write sequence has been buffered.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
532 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 18-25. Example Mass Erase Command Flow
Write: Flash Block Address
Write: FCMD register
Mass Erase Command 0x41
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 533
Rev 01.24
18.4.1.4 Illegal Flash Operations
18.4.1.4.1 Access Error
The ACCERR flag in the FSTAT register will be set during the command write sequence if any of the
following illegal Flash operations are performed causing the command write sequence to immediately
abort:
1. Writing to the Flash address space before initializing the FCLKDIV register
2. Writing a misaligned word or a byte to the valid Flash address space
3. Writing to the Flash address space while CBEIF is not set
4. Writing a second word to the Flash address space before executing a program or erase command
on the previously written word
5. Writing to any Flash register other than FCMD after writing a word to the Flash address space
6. Writing a second command to the FCMD register before executing the previously written
command
7. Writing an invalid command to the FCMD register
8. Writing to any Flash register other than FSTAT (to clear CBEIF) after writing to the FCMD register
9. The part enters stop mode and a program or erase command is in progress. The command is aborted
and any pending command is killed
10. When security is enabled, a command other than mass erase originating from a non-secure memory
or from the background debug mode is written to the FCMD register
11. A 0 is written to the CBEIF bit in the FSTAT register to abort a command write sequence.
The ACCERR flag will not be set if any Flash register is read during the command write sequence. If the
Flash array is read during execution of an algorithm (CCIF=0), the Flash module will return invalid data
and the ACCERR flag will not be set. If an ACCERR flag is set in the FSTAT register, the Flash command
controller is locked. It is not possible to launch another command until the ACCERR flag is cleared.
18.4.1.4.2 Protection Violation
The PVIOL flag in the FSTAT register will be set during the command write sequence after the word write
to the Flash address space if any of the following illegal Flash operations are performed, causing the
command write sequence to immediately abort:
1. Writing a Flash address to program in a protected area of the Flash array (see Section 18.3.2.5).
2. Writing a Flash address to erase in a protected area of the Flash array.
3. Writing the mass erase command to the FCMD register while any protection is enabled.
If the PVIOL flag is set, the Flash command controller is locked. It is not possible to launch another
command until the PVIOL flag is cleared.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
534 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
18.4.2 Operating Modes
18.4.2.1 Wait Mode
If the MCU enters wait mode while a Flash command is active (CCIF = 0), that command and any buffered
command will be completed.
The Flash module can recover the MCU from wait mode if the interrupts are enabled (see Section 18.4.5).
18.4.2.2 Stop Mode
If the MCU enters stop mode while a Flash command is active (CCIF = 0), that command will be aborted
and the data being programmed or erased is lost. The high voltage circuitry to the Flash array will be
switched off when entering stop mode. CCIF and ACCERR flags will be set. Upon exit from stop mode,
the CBEIF flag will be set and any buffered command will not be executed. The ACCERR flag must be
cleared before returning to normal operation.
NOTE
As active Flash commands are immediately aborted when the MCU enters
stop mode, it is strongly recommended that the user does not use the STOP
instruction during program and erase execution.
18.4.2.3 Background Debug Mode
In background debug mode (BDM), the FPROT register is writable. If the MCU is unsecured, then all
Flash commands listed in Table 18-16 can be executed. If the MCU is secured and is in special single chip
mode, the only possible command to execute is mass erase.
18.4.3 Flash Module Security
The Flash module provides the necessary security information to the MCU. After each reset, the Flash
module determines the security state of the MCU as defined in Section 18.3.2.2, “Flash Security Register
(FSEC)”.
The contents of the Flash security/options byte at address 0xFF0F in the Flash configuration field must be
changed directly by programming address 0xFF0F when the device is unsecured and the higher address
sector is unprotected. If the Flash security/options byte is left in the secure state, any reset will cause the
MCU to return to the secure operating mode.
18.4.3.1 Unsecuring the MCU using Backdoor Key Access
The MCU may only be unsecured by using the backdoor key access feature which requires knowledge of
the contents of the backdoor key (four 16-bit words programmed at addresses 0xFF00–0xFF07). If
KEYEN[1:0] = 1:0 and the KEYACC bit is set, a write to a backdoor key address in the Flash array triggers
a comparison between the written data and the backdoor key data stored in the Flash array. If all four words
of data are written to the correct addresses in the correct order and the data matches the backdoor key
stored in the Flash array, the MCU will be unsecured. The data must be written to the backdoor key
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 535
Rev 01.24
addresses sequentially staring with 0xFF00-0xFF01 and ending with 0xFF06–0xFF07. The values 0x0000
and 0xFFFF are not permitted as keys. When the KEYACC bit is set, reads of the Flash array will return
invalid data.
The user code stored in the Flash array must have a method of receiving the backdoor key from an external
stimulus. This external stimulus would typically be through one of the on-chip serial ports.
If KEYEN[1:0] = 1:0 in the FSEC register, the MCU can be unsecured by the backdoor key access
sequence described below:
1. Set the KEYACC bit in the FCNFG register
2. Write the correct four 16-bit words to Flash addresses 0xFF00–0xFF07 sequentially starting with
0xFF00
3. Clear the KEYACC bit in the FCNFG register
4. If all four 16-bit words match the backdoor key stored in Flash addresses 0xFF00–0xFF07, the
MCU is unsecured and bits SEC[1:0] in the FSEC register are forced to the unsecure state of 1:0
The backdoor key access sequence is monitored by the internal security state machine. An illegal operation
during the backdoor key access sequence will cause the security state machine to lock, leaving the MCU
in the secured state. A reset of the MCU will cause the security state machine to exit the lock state and
allow a new backdoor key access sequence to be attempted. The following illegal operations will lock the
security state machine:
1. If any of the four 16-bit words does not match the backdoor key programmed in the Flash array
2. If the four 16-bit words are written in the wrong sequence
3. If more than four 16-bit words are written
4. If any of the four 16-bit words written are 0x0000 or 0xFFFF
5. If the KEYACC bit does not remain set while the four 16-bit words are written
After the backdoor key access sequence has been correctly matched, the MCU will be unsecured. The
Flash security byte can be programmed to the unsecure state, if desired.
In the unsecure state, the user has full control of the contents of the four word backdoor key by
programming bytes 0xFF00–0xFF07 of the Flash configuration field.
The security as defined in the Flash security/options byte at address 0xFF0F is not changed by using the
backdoor key access sequence to unsecure. The backdoor key stored in addresses 0xFF00–0xFF07 is
unaffected by the backdoor key access sequence. After the next reset sequence, the security state of the
Flash module is determined by the Flash security/options byte at address 0xFF0F. The backdoor key access
sequence has no effect on the program and erase protection defined in the FPROT register.
It is not possible to unsecure the MCU in special single chip mode by executing the backdoor key access
sequence in background debug mode.
Chapter 18 32 Kbyte Flash Module (S12FTS32KV1)
536 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
18.4.4 Flash Reset Sequence
On each reset, the Flash module executes a reset sequence to hold CPU activity while loading the following
registers from the Flash array memory according to Table 18-1:
• FPROT — Flash Protection Register (see Section 18.3.2.5)
• FSEC — Flash Security Register (see Section 18.3.2.2)
18.4.4.1 Reset While Flash Command Active
If a reset occurs while any Flash command is in progress, that command will be immediately aborted. The
state of the word being programmed or the sector/array being erased is not guaranteed.
18.4.5 Interrupts
The Flash module can generate an interrupt when all Flash commands have completed execution or the
Flash address, data, and command buffers are empty.
NOTE
Vector addresses and their relative interrupt priority are determined at the
MCU level.
18.4.5.1 Description of Interrupt Operation
Figure 18-26 shows the logic used for generating interrupts.
The Flash module uses the CBEIF and CCIF flags in combination with the enable bits CBIE and CCIE to
discriminate for the generation of interrupts.
Figure 18-26. Flash Interrupt Implementation
For a detailed description of these register bits, refer to Section 18.3.2.4, “Flash Configuration Register
(FCNFG)” and Section 18.3.2.6, “Flash Status Register (FSTAT)”.
Table 18-17. Flash Interrupt Sources
Interrupt Source Interrupt Flag Local Enable Global (CCR) Mask
Flash Address, Data, and Command
Buffers are empty
CBEIF
(FSTAT register)
CBEIE I Bit
All Flash commands have completed
execution
CCIF
(FSTAT register)
CCIE I Bit
CBEIF
CBEIE
CCIF
CCIE
FLASH INTERRUPT REQUEST
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 537
Rev 01.24
Chapter 19
64 Kbyte Flash Module (S12FTS64KV4)
19.1 Introduction
The FTS128K1FTS64K module implements a 12864 Kbyte Flash (nonvolatile) memory. The Flash
memory contains one array of 12864 Kbytes organized as 1024512 rows of 128128 bytes with an erase
sector size of eight rows (10241024 bytes). The Flash array may be read as either bytes, aligned words, or
misaligned words. Read access time is one bus cycle for byte and aligned word, and two bus cycles for
misaligned words.
The Flash array is ideal for program and data storage for single-supply applications allowing for field
reprogramming without requiring external voltage sources for program or erase. Program and erase
functions are controlled by a command driven interface. The Flash module supports both mass erase and
sector erase. An erased bit reads 1 and a programmed bit reads 0. The high voltage required to program
and erase is generated internally. It is not possible to read from a Flash array while it is being erased or
programmed.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
19.1.1 Glossary
Command Write Sequence — A three-step MCU instruction sequence to program, erase, or erase verify
the Flash array memory.
19.1.2 Features
•12864 Kbytes of Flash memory comprised of one 12864 Kbyte array divided into 12864 sectors of
10241024 bytes
• Automated program and erase algorithm
• Interrupts on Flash command completion and command buffer empty
• Fast sector erase and word program operation
• 2-stage command pipeline for faster multi-word program times
• Flexible protection scheme to prevent accidental program or erase
• Single power supply for Flash program and erase operations
• Security feature to prevent unauthorized access to the Flash array memory
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
538 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.1.3 Modes of Operation
See Section 19.4.2, “Operating Modes” for a description of the Flash module operating modes. For
program and erase operations, refer to Section 19.4.1, “Flash Command Operations”.
19.1.4 Block Diagram
Figure 19-1Figure 19-2 shows a block diagram of the FTS128K1FTS64K module.
Figure 19-1. FTS128K1 Block Diagram
FTS128K1
Oscillator
Clock
Command
Complete
Interrupt
Command
Buffer Empty
Interrupt
Flash Array
64K * 16 Bits
sector 0
sector 1
sector 127
Clock
Divider FCLK
Protection
Security
Command Pipeline
cmd2
addr2
data2
cmd1
addr1
data1
Registers
Flash
Interface
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 539
Rev 01.24
Figure 19-2. FTS64K Block Diagram
19.2 External Signal Description
The FTS128K1FTS64K module contains no signals that connect off-chip.
19.3 Memory Map and Registers
This section describes the FTS128K1FTS64K memory map and registers.
19.3.1 Module Memory Map
The FTS128K1FTS64K memory map is shown in Figure 19-3Figure 19-4. The HCS12 architecture places
the Flash array addresses between 0x40000x4000 and 0xFFFF, which corresponds to three 16 Kbyte
pages. The content of the HCS12 Core PPAGE register is used to map the logical middle page ranging from
FTS64K
Oscillator
Clock
Command
Complete
Interrupt
Command
Buffer Empty
Interrupt
Flash Array
32K * 16 Bits
sector 0
sector 1
sector 63
Clock
Divider FCLK
Protection
Security
Command Pipeline
cmd2
addr2
data2
cmd1
addr1
data1
Registers
Flash
Interface
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
540 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
address 0x8000 to 0xBFFF to any physical 16K byte page in the Flash array memory.1The FPROT register
(see Section 19.3.2.5) can be set to globally protect the entire Flash array. Three separate areas, one starting
from the Flash array starting address (called lower) towards higher addresses, one growing downward from
the Flash array end address (called higher), and the remaining addresses, can be activated for protection.
The Flash array addresses covered by these protectable regions are shown in Figure 19-3Figure 19-4. The
higher address area is mainly targeted to hold the boot loader code since it covers the vector space. The
lower address area can be used for EEPROM emulation in an MCU without an EEPROM module since it
can be left unprotected while the remaining addresses are protected from program or erase. Default
protection settings as well as security information that allows the MCU to restrict access to the Flash
module are stored in the Flash configuration field described in Table 19-1.
1. By placing 0x3E/0x3F in the HCS12 Core PPAGE register, the bottom/top fixed 16 Kbyte pagescan be seen twice in the MCU
memory map.
Table 19-1. Flash Configuration Field
Flash Address Size
(bytes) Description
0xFF00–0xFF07 8 Backdoor Key to unlock security
0xFF08–0xFF0C 5 Reserved
0xFF0D 1 Flash Protection byte
Refer to Section 19.3.2.5, “Flash Protection Register (FPROT)”
0xFF0E 1 Reserved
0xFF0F 1 Flash Security/Options byte
Refer to Section 19.3.2.2, “Flash Security Register (FSEC)”
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 541
Rev 01.24
Figure 19-3. Flash Memory Map
Flash Registers
MODULE BASE + 0x0000
0xFF00–0xFF0F (Flash Configuration Field)
MODULE BASE + 0x000F
0x8000
Flash Protected Low Sectors
1, 2, 4, 8 Kbytes
FLASH_START = 0x4000
0x5000
0x4400
0x6000
16K PAGED
MEMORY
0x38 0x39 0x3A 0x3B
0x3E
0x3C 0x3D 003E 0x3F
Note: 0x38–0x3F correspond to the PPAGE register content
FLASH_END = 0xFFFF
0xF800
0xF000
0xC000
0xE000 Flash Protected High Sectors
2, 4, 8, 16 Kbytes
0x3F
0x4800
Flash Array
16 bytes
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
542 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 19-4. Flash Memory Map
Flash Registers
MODULE BASE + 0x0000
0xFF00–0xFF0F (Flash Configuration Field)
MODULE BASE + 0x000F
0x8000
Flash Protected Low Sectors
1, 2, 4, 8 Kbytes
FLASH_START = 0x4000
0x5000
0x4400
0x6000
16K PAGED
MEMORY
0x3E
0x3C 0x3D 003E 0x3F
Note: 0x3C–0x3F correspond to the PPAGE register content
FLASH_END = 0xFFFF
0xF800
0xF000
0xC000
0xE000 Flash Protected High Sectors
2, 4, 8, 16 Kbytes
0x3F
0x4800
Flash Array
16 bytes
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 543
Rev 01.24
Table 19-2. Flash Array Memory Map Summary
MCU Address
Range PPAGE Protectable
Low Range
Protectable
High Range
Array Relative
Address(1)
1. Inside Flash block.
0x0000–0x3FFF(2)
2. If allowed by MCU.
Unpaged
(0x3D)
N.A. N.A. 0x14000–0x17FFF
0x4000–0x7FFF Unpaged
(0x3E)
0x4000–0x43FF N.A. 0x18000–0x1BFFF
0x4000–0x47FF
0x4000–0x4FFF
0x4000–0x5FFF
0x8000–0xBFFF 0x38 N.A. N.A. 0x00000–0x03FFF
0x39 N.A. N.A. 0x04000–0x07FFF
0x3A N.A. N.A. 0x08000–0x0BFFF
0x3B N.A. N.A. 0x0C000–0x0FFFF
0x3C N.A. N.A. 0x10000–0x13FFF
0x3D N.A. N.A. 0x14000–0x17FFF
0x3E 0x8000–0x83FF N.A. 0x18000–0x1BFFF
0x8000–0x87FF
0x8000–0x8FFF
0x8000–0x9FFF
0x3F N.A. 0xB800–0xBFFF 0x1C000–0x1FFFF
0xB000–0xBFFF
0xA000–0xBFFF
0x8000–0xBFFF
0xC000–0xFFFF Unpaged
(0x3F)
N.A. 0xF800–0xFFFF 0x1C000–0x1FFFF
0xF000–0xFFFF
0xE000–0xFFFF
0xC000–0xFFFF
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
544 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 19-3. Flash Array Memory Map Summary
MCU Address
Range PPAGE Protectable
Low Range
Protectable
High Range
Array Relative
Address(1)
1. Inside Flash block.
0x0000–0x3FFF(2)
2. If allowed by MCU.
Unpaged
(0x3D)
N.A. N.A. 0x14000–0x17FFF
0x4000–0x7FFF Unpaged
(0x3E)
0x4000–0x43FF N.A. 0x18000–0x1BFFF
0x4000–0x47FF
0x4000–0x4FFF
0x4000–0x5FFF
0x8000–0xBFFF 0x3C N.A. N.A. 0x10000–0x13FFF
0x3D N.A. N.A. 0x14000–0x17FFF
0x3E 0x8000–0x83FF N.A. 0x18000–0x1BFFF
0x8000–0x87FF
0x8000–0x8FFF
0x8000–0x9FFF
0x3F N.A. 0xB800–0xBFFF 0x1C000–0x1FFFF
0xB000–0xBFFF
0xA000–0xBFFF
0x8000–0xBFFF
0xC000–0xFFFF Unpaged
(0x3F)
N.A. 0xF800–0xFFFF 0x1C000–0x1FFFF
0xF000–0xFFFF
0xE000–0xFFFF
0xC000–0xFFFF
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 545
Rev 01.24
19.3.2 Register Descriptions
The Flash module contains a set of 16 control and status registers located between module base + 0x0000
and 0x000F. A summary of the Flash module registers is given in Figure 19-5. Detailed descriptions of
each register bit are provided.
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000
FCLKDIV
R FDIVLD PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
0x0001
FSEC
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
0x0002
RESERVED1
(1)
1. Intended for factory test purposes only.
R00000000
W
0x0003
FCNFG
RCBEIE CCIE KEYACC 00000
W
0x0004
FPROT
RFPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
0x0005
FSTAT
RCBEIF CCIF PVIOL ACCERR 0 BLANK FAIL DONE
W
0x0006
FCMD
R0 CMDB6 CMDB5 00
CMDB2 0CMDB0
W
0x0007
RESERVED21
R00000000
W
0x0008
FADDRHI1
RFABHI
W
0x0008
FADDRHI1
R 0 FABHI
W
0x0009
FADDRLO1
RFABLO
W
0x000A
FDATAHI1
RFDHI
W
0x000B
FDATALO1
RFDLO
W
0x000C
RESERVED31
R00000000
W
0x000D
RESERVED41
R00000000
W
0x000E
RESERVED51
R00000000
W
0x000F
RESERVED61
R00000000
W
= Unimplemented or Reserved
Figure 19-5. Flash Register Summary
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
546 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.3.2.1 Flash Clock Divider Register (FCLKDIV)
The FCLKDIV register is used to control timed events in program and erase algorithms.
All bits in the FCLKDIV register are readable, bits 6–0 are write once and bit 7 is not writable.
19.3.2.2 Flash Security Register (FSEC)
The FSEC register holds all bits associated with the security of the MCU and Flash module.
All bits in the FSEC register are readable but not writable.
The FSEC register is loaded from the Flash configuration field at 0xFF0F during the reset sequence,
indicated by F in Figure 19-7.
Module Base + 0x0000
76543210
R FDIVLD
PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-6. Flash Clock Divider Register (FCLKDIV)
Table 19-4. FCLKDIV Field Descriptions
Field Description
7
FDIVLD
Clock Divider Loaded
0 FCLKDIV register has not been written
1 FCLKDIV register has been written to since the last reset
6
PRDIV8
Enable Prescalar by 8
0 The oscillator clock is directly fed into the Flash clock divider
1 The oscillator clock is divided by 8 before feeding into the Flash clock divider
5–0
FDIV[5:0]
Clock Divider Bits — The combination of PRDIV8 and FDIV[5:0] must divide the oscillator clock down to a
frequency of 150 kHz – 200 kHz. The maximum divide ratio is 512. Refer to Section 19.4.1.1, “Writing the
FCLKDIV Register” for more information.
Module Base + 0x0001
76543210
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
Reset F F FFFFFF
= Unimplemented or Reserved
Figure 19-7. Flash Security Register (FSEC)
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 547
Rev 01.24
The security function in the Flash module is described in Section 19.4.3, “Flash Module Security”.
19.3.2.3 RESERVED1
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
Table 19-5. FSEC Field Descriptions
Field Description
7–6
KEYEN[1:0]
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of the backdoor key access
to the Flash module as shown in Table 19-6.
5–2
NV[5:2]
Nonvolatile Flag Bits — The NV[5:2] bits are available to the user as nonvolatile flags.
1–0
SEC[1:0]
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in Table 19-7. If the
Flash module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
Table 19-6. Flash KEYEN States
KEYEN[1:0] Status of Backdoor Key Access
00 DISABLED
01(1)
1. Preferred KEYEN state to disable Backdoor Key Access.
DISABLED
10 ENABLED
11 DISABLED
Table 19-7. Flash Security States
SEC[1:0] Status of Security
00 Secured
01(1)
1. Preferred SEC state to set MCU to secured state.
Secured
10 Unsecured
11 Secured
Module Base + 0x0002
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-8. RESERVED1
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
548 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.3.2.4 Flash Configuration Register (FCNFG)
The FCNFG register enables the Flash interrupts and gates the security backdoor key writes.
CBEIE, CCIE, and KEYACC are readable and writable while remaining bits read 0 and are not writable.
KEYACC is only writable if the KEYEN bit in the FSEC register is set to the enabled state (see Section
19.3.2.2).
19.3.2.5 Flash Protection Register (FPROT)
The FPROT register defines which Flash sectors are protected against program or erase.
The FPROT register is readable in normal and special modes. FPOPEN can only be written from a 1 to a 0.
FPLS[1:0] can be written anytime until FPLDIS is cleared. FPHS[1:0] can be written anytime until
Module Base + 0x0003
76543210
R
CBEIE CCIE KEYACC
00000
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-9. Flash Configuration Register (FCNFG)
Table 19-8. FCNFG Field Descriptions
Field Description
7
CBEIE
Command Buffer Empty Interrupt Enable — The CBEIE bit enables the interrupts in case of an empty
command buffer in the Flash module.
0 Command Buffer Empty interrupts disabled
1 An interrupt will be requested whenever the CBEIF flag is set (see Section 19.3.2.6)
6
CCIE
Command Complete Interrupt Enable — The CCIE bit enables the interrupts in case of all commands being
completed in the Flash module.
0 Command Complete interrupts disabled
1 An interrupt will be requested whenever the CCIF flag is set (see Section 19.3.2.6)
5
KEYACC
Enable Security Key Writing.
0 Flash writes are interpreted as the start of a command write sequence
1 Writes to the Flash array are interpreted as a backdoor key while reads of the Flash array return invalid data
Module Base + 0x0004
76543210
R
FPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
Reset F F FFFFFF
Figure 19-10. Flash Protection Register (FPROT)
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 549
Rev 01.24
FPHDIS is cleared. The FPROT register is loaded from Flash address 0xFF0D during the reset sequence,
indicated by F in Figure 19-10.
To change the Flash protection that will be loaded on reset, the upper sector of the Flash array must be
unprotected, then the Flash protection byte located at Flash address 0xFF0D must be written to.
A protected Flash sector is disabled by FPHDIS and FPLDIS while the size of the protected sector is
defined by FPHS[1:0] and FPLS[1:0] in the FPROT register.
Trying to alter any of the protected areas will result in a protect violation error and the PVIOL flag will be
set in the FSTAT register (see Section 19.3.2.6). A mass erase of the whole Flash array is only possible
when protection is fully disabled by setting the FPOPEN, FPLDIS, and FPHDIS bits. An attempt to mass
erase a Flash array while protection is enabled will set the PVIOL flag in the FSTAT register.
Table 19-9. FPROT Field Descriptions
Field Description
7
FPOPEN
Protection Function for Program or Erase — It is possible using the FPOPEN bit to either select address
ranges to be protected using FPHDIS, FPLDIS, FPHS[1:0] and FPLS[1:0] or to select the same ranges to be
unprotected. When FPOPEN is set, FPxDIS enables the ranges to be protected, whereby clearing FPxDIS
enables protection for the range specified by the corresponding FPxS[1:0] bits. When FPOPEN is cleared,
FPxDIS defines unprotected ranges as specified by the corresponding FPxS[1:0] bits. In this case, setting
FPxDIS enables protection. Thus the effective polarity of the FPxDIS bits is swapped by the FPOPEN bit as
shown in Table 19-10. This function allows the main part of the Flash array to be protected while a small range
can remain unprotected for EEPROM emulation.
0 The FPHDIS and FPLDIS bits define Flash address ranges to be unprotected
1 The FPHDIS and FPLDIS bits define Flash address ranges to be protected
6
NV6
Nonvolatile Flag Bit — The NV6 bit should remain in the erased state for future enhancements.
5
FPHDIS
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in the higher space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
4–3
FPHS[1:0]
Flash Protection Higher Address Size — The FPHS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 19-11. The FPHS[1:0] bits can only be written to while the FPHDIS bit is set.
2
FPLDIS
Flash Protection Lower Address Range Disable — The FPLDIS bit determines whether there is a
protected/unprotected sector in the lower space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
1–0
FPLS[1:0]
Flash Protection Lower Address Size — The FPLS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 19-12. The FPLS[1:0] bits can only be written to while the FPLDIS bit is set.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
550 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 19-11 illustrates all possible protection scenarios. Although the protection scheme is loaded from
the Flash array after reset, it is allowed to change in normal modes. This protection scheme can be used by
applications requiring re-programming in single chip mode while providing as much protection as possible
if no re-programming is required.
Table 19-10. Flash Protection Function
FPOPEN FPHDIS FPHS[1] FPHS[0] FPLDIS FPLS[1] FPLS[0] Function(1)
1. For range sizes refer to Table 19-11 and Table 19-12 or .
1 1 x x 1 x x No protection
1 1 x x 0 x x Protect low range
1 0 x x 1 x x Protect high range
1 0 x x 0 x x Protect high and low ranges
0 1 x x 1 x x Full Flash array protected
0 0 x x 1 x x Unprotected high range
0 1 x x 0 x x Unprotected low range
0 0 x x 0 x x Unprotected high and low ranges
Table 19-11. Flash Protection Higher Address Range
FPHS[1:0] Address Range Range Size
00 0xF800–0xFFFF 2 Kbytes
01 0xF000–0xFFFF 4 Kbytes
10 0xE000–0xFFFF 8 Kbytes
11 0xC000–0xFFFF 16 Kbytes
Table 19-12. Flash Protection Lower Address Range
FPLS[1:0] Address Range Range Size
00 0x4000–0x43FF 1 Kbyte
01 0x4000–0x47FF 2 Kbytes
10 0x4000–0x4FFF 4 Kbytes
11 0x4000–0x5FFF 8 Kbytes
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 551
Rev 01.24
Figure 19-11. Flash Protection Scenarios
19.3.2.5.1 Flash Protection Restrictions
The general guideline is that protection can only be added, not removed. All valid transitions between
Flash protection scenarios are specified in Table 19-13. Any attempt to write an invalid scenario to the
FPROT register will be ignored and the FPROT register will remain unchanged. The contents of the
FPROT register reflect the active protection scenario.
Table 19-13. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
0 XXXX
1XX
2XX
3X
4XX
5 XXXX
7654
FPOPEN = 1
3210
FPHS[1:0] FPLS[1:0]
FPOPEN = 0
FPHDIS = 1
FPLDIS = 1
FPHDIS = 1
FPLDIS = 0
FPHDIS = 0
FPLDIS = 1
FPHDIS = 0
FPLDIS = 0
Scenario
Scenario
Protected Flash
FPHS[1:0] FPLS[1:0]
0xFFFF
0xFFFF
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
552 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.3.2.6 Flash Status Register (FSTAT)
The FSTAT register defines the status of the Flash command controller and the results of command
execution.
In normal modes, bits CBEIF, PVIOL, and ACCERR are readable and writable, bits CCIF and BLANK
are readable and not writable, remaining bits, including FAIL and DONE, read 0 and are not writable. In
special modes, FAIL is readable and writable while DONE is readable but not writable. FAIL must be clear
in special modes when starting a command write sequence.
6XXXX
7 XXXXXXXX
1. Allowed transitions marked with X.
Module Base + 0x0005
76543210
R
CBEIF
CCIF
PVIOL ACCERR
0 BLANK
FAIL
DONE
W
Reset 11000001
= Unimplemented or Reserved
Figure 19-12. Flash Status Register (FSTAT)
Table 19-14. FSTAT Field Descriptions
Field Description
7
CBEIF
Command Buffer Empty Interrupt Flag — The CBEIF flag indicates that the address, data and command
buffers are empty so that a new command write sequence can be started. The CBEIF flag is cleared by writing
a 1 to CBEIF. Writing a 0 to the CBEIF flag has no effect on CBEIF. Writing a 0 to CBEIF after writing an aligned
word to the Flash address space but before CBEIF is cleared will abort a command write sequence and cause
the ACCERR flag in the FSTAT register to be set. Writing a 0 to CBEIF outside of a command write sequence
will not set the ACCERR flag. The CBEIF flag is used together with the CBEIE bit in the FCNFG register to
generate an interrupt request (see Figure 19-29).
0 Buffers are full
1 Buffers are ready to accept a new command
6
CCIF
Command Complete Interrupt Flag — The CCIF flag indicates that there are no more commands pending. The
CCIF flag is cleared when CBEIF is clear and sets automatically upon completion of all active and pending
commands. The CCIF flag does not set when an active commands completes and a pending command is
fetched from the command buffer. Writing to the CCIF flag has no effect. The CCIF flag is used together with the
CCIE bit in the FCNFG register to generate an interrupt request (see Figure 19-29).
0 Command in progress
1 All commands are completed
Table 19-13. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 553
Rev 01.24
19.3.2.7 Flash Command Register (FCMD)
The FCMD register defines the Flash commands.
Bits CMDB6, CMDB5, CMDB2, and CMDB0 are readable and writable during a command write
sequence while bits 7, 4, 3, and 1 read 0 and are not writable.
5
PVIOL
Protection Violation — The PVIOL flag indicates an attempt was made to program or erase an address in a
protected Flash array memory area. The PVIOL flag is cleared by writing a 1 to PVIOL. Writing a 0 to the PVIOL
flag has no effect on PVIOL. While PVIOL is set, it is not possible to launch another command.
0 No protection violation detected
1 Protection violation has occurred
4
ACCERR
Access Error — The ACCERR flag indicates an illegal access to the Flash array caused by either a violation of
the command write sequence, issuing an illegal command (illegal combination of the CMDBx bits in the FCMD
register) or the execution of a CPU STOP instruction while a command is executing (CCIF=0). The ACCERR flag
is cleared by writing a 1 to ACCERR. Writing a 0 to the ACCERR flag has no effect on ACCERR. While ACCERR
is set, it is not possible to launch another command.
0 No access error detected
1 Access error has occurred
2
BLANK
Flash Array Has Been Verified as Erased — The BLANK flag indicates that an erase verify command has
checked the Flash array and found it to be erased. The BLANK flag is cleared by hardware when CBEIF is
cleared as part of a new valid command write sequence. Writing to the BLANK flag has no effect on BLANK.
0 If an erase verify command has been requested, and the CCIF flag is set, then a 0 in BLANK indicates the
array is not erased
1 Flash array verifies as erased
1
FAIL
Flag Indicating a Failed Flash Operation — In special modes, the FAIL flag will set if the erase verify operation
fails (Flash array verified as not erased). Writing a 0 to the FAIL flag has no effect on FAIL. The FAIL flag is cleared
by writing a 1 to FAIL. While FAIL is set, it is not possible to launch another command.
0 Flash operation completed without error
1 Flash operation failed
0
DONE
Flag Indicating a Failed Operation is not Active — In special modes, the DONE flag will clear if a program,
erase, or erase verify operation is active.
0 Flash operation is active
1 Flash operation is not active
Module Base + 0x0006
76543210
R0
CMDB6 CMDB5
00
CMDB2
0
CMDB0
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-13. Flash Command Register (FCMD)
Table 19-14. FSTAT Field Descriptions
Field Description
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
554 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.3.2.8 RESERVED2
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
19.3.2.9 Flash Address Register (FADDR)
FADDRHI and FADDRLO are the Flash address registers.
\
Table 19-15. FCMD Field Descriptions
Field Description
6, 5, 2, 0
CMDB[6:5]
CMDB[2]
CMDB[0]
Valid Flash commands are shown in Table 19-16. An attempt to execute any command other than those listed in
Table 19-16 will set the ACCERR bit in the FSTAT register (see Section 19.3.2.6).
Table 19-16. Valid Flash Command List
CMDB NVM Command
0x05 Erase verify
0x20 Word program
0x40 Sector erase
0x41 Mass erase
Module Base + 0x0007
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-14. RESERVED2
Module Base + 0x0008
76543210
R
FABHI
W
Reset 00000000
Figure 19-15. Flash Address High Register (FADDRHI)
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 555
Rev 01.24
\
\
\
In normal modes, all FABHI and FABLO bits read 0 and are not writable. In special modes, the FABHI
and FABLO bits are readable and writable. For sector erase, the MCU address bits [9:0] are ignored.For
mass erase, any address within the Flash array is valid to start the command.
19.3.2.10 Flash Data Register (FDATA)
FDATAHI and FDATALO are the Flash data registers.
In normal modes, all FDATAHI and FDATALO bits read 0 and are not writable. In special modes, all
FDATAHI and FDATALO bits are readable and writable when writing to an address within the Flash
address range.
Module Base + 0x0008
76543210
R0
FABHI
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-16. Flash Address High Register (FADDRHI)
Module Base + 0x0009
76543210
R
FABLO
W
Reset 00000000
Figure 19-17. Flash Address Low Register (FADDRLO)
Module Base + 0x000A
76543210
R
FDHI
W
Reset 00000000
Figure 19-18. Flash Data High Register (FDATAHI)
Module Base + 0x000B
76543210
R
FDLO
W
Reset 00000000
Figure 19-19. Flash Data Low Register (FDATALO)
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
556 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.3.2.11 RESERVED3
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
19.3.2.12 RESERVED4
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
19.3.2.13 RESERVED5
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
Module Base + 0x000C
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-20. RESERVED3
Module Base + 0x000D
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-21. RESERVED4
Module Base + 0x000E
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-22. RESERVED5
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 557
Rev 01.24
19.3.2.14 RESERVED6
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
19.4 Functional Description
19.4.1 Flash Command Operations
Write operations are used for the program, erase, and erase verify algorithms described in this section. The
program and erase algorithms are controlled by a state machine whose timebase FCLK is derived from the
oscillator clock via a programmable divider. The FCMD register as well as the associated FADDR and
FDATA registers operate as a buffer and a register (2-stage FIFO) so that a new command along with the
necessary data and address can be stored to the buffer while the previous command is still in progress. This
pipelined operation allows a time optimization when programming more than one word on a specific row,
as the high voltage generation can be kept active in between two programming commands. The pipelined
operation also allows a simplification of command launching. Buffer empty as well as command
completion are signalled by flags in the FSTAT register with corresponding interrupts generated, if
enabled.
The next sections describe:
• How to write the FCLKDIV register
• Command write sequence used to program, erase or erase verify the Flash array
• Valid Flash commands
• Errors resulting from illegal Flash operations
19.4.1.1 Writing the FCLKDIV Register
Prior to issuing any Flash command after a reset, it is first necessary to write the FCLKDIV register to
divide the oscillator clock down to within the 150-kHz to 200-kHz range. Since the program and erase
timings are also a function of the bus clock, the FCLKDIV determination must take this information into
account.
If we define:
• FCLK as the clock of the Flash timing control block
Module Base + 0x000F
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 19-23. RESERVED6
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
558 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
• Tbus as the period of the bus clock
• INT(x) as taking the integer part of x (e.g., INT(4.323) = 4),
then FCLKDIV register bits PRDIV8 and FDIV[5:0] are to be set as described in Figure 19-24.
For example, if the oscillator clock frequency is 950 kHz and the bus clock is 10 MHz, FCLKDIV bits
FDIV[5:0] should be set to 4 (000100) and bit PRDIV8 set to 0. The resulting FCLK is then 190 kHz. As
a result, the Flash algorithm timings are increased over optimum target by:
Command execution time will increase proportionally with the period of FCLK.
CAUTION
Because of the impact of clock synchronization on the accuracy of the
functional timings, programming or erasing the Flash array cannot be
performed if the bus clock runs at less than 1 MHz. Programming or erasing
the Flash array with an input clock < 150 kHz should be avoided. Setting
FCLKDIV to a value such that FCLK < 150 kHz can destroy the Flash array
due to overstress. Setting FCLKDIV to a value such that (1/FCLK + Tbus)
< 5µs can result in incomplete programming or erasure of the Flash array
cells.
If the FCLKDIV register is written, the bit FDIVLD is set automatically. If the FDIVLD bit is 0, the
FCLKDIV register has not been written since the last reset. If the FCLKDIV register has not been written
to, the Flash command loaded during a command write sequence will not execute and the ACCERR flag
in the FSTAT register will set.
200 190–()200⁄100×5%=
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 559
Rev 01.24
Figure 19-24. PRDIV8 and FDIV Bits Determination Procedure
PRDIV8=1
yes
no
PRDIV8=0 (reset)
12.8MHz?
FCLK=(PRDCLK)/(1+FDIV[5:0])
PRDCLK=oscillator_clock
PRDCLK=oscillator_clock/8
PRDCLK[MHz]*(5+Tbus[µs]) no
FDIV[5:0]=PRDCLK[MHz]*(5+Tbus[µs])-1
yes
START
Tbus < 1µs?
an integer?
FDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[µs]))
1/FCLK[MHz] + Tbus[µs] > 5
AND
FCLK > 0.15MHz
?
END
yes
no
FDIV[5:0] > 4?
ALL COMMANDS IMPOSSIBLE
yes
no
ALL COMMANDS IMPOSSIBLE
no
TRY TO DECREASE Tbus
yes
oscillator_clock
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
560 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.4.1.2 Command Write Sequence
The Flash command controller is used to supervise the command write sequence to execute program,
erase, and erase verify algorithms.
Before starting a command write sequence, the ACCERR and PVIOL flags in the FSTAT register must be
clear and the CBEIF flag should be tested to determine the state of the address, data, and command buffers.
If the CBEIF flag is set, indicating the buffers are empty, a new command write sequence can be started.
If the CBEIF flag is clear, indicating the buffers are not available, a new command write sequence will
overwrite the contents of the address, data, and command buffers.
A command write sequence consists of three steps which must be strictly adhered to with writes to the
Flash module not permitted between the steps. However, Flash register and array reads are allowed during
a command write sequence. The basic command write sequence is as follows:
1. Write to a valid address in the Flash array memory.
2. Write a valid command to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the command.
The address written in step 1 will be stored in the FADDR registers and the data will be stored in the
FDATA registers. When the CBEIF flag is cleared in step 3, the CCIF flag is cleared by the Flash command
controller indicating that the command was successfully launched. For all command write sequences, the
CBEIF flag will set after the CCIF flag is cleared indicating that the address, data, and command buffers
are ready for a new command write sequence to begin. A buffered command will wait for the active
operation to be completed before being launched. Once a command is launched, the completion of the
command operation is indicated by the setting of the CCIF flag in the FSTAT register. The CCIF flag will
set upon completion of all active and buffered commands.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 561
Rev 01.24
19.4.1.3 Valid Flash Commands
Table 19-17 summarizes the valid Flash commands along with the effects of the commands on the Flash
array.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
Table 19-17. Valid Flash Commands
FCMD Meaning Function on Flash Array
0x05 Erase
Verify
Verify all bytes in the Flash array are erased.
If the Flash array is erased, the BLANK bit will set in the FSTAT register upon command completion.
0x20 Program Program a word (2 bytes) in the Flash array.
0x40 Sector
Erase
Erase all 1024 bytes in a sector of the Flash array.
0x41 Mass
Erase
Erase all bytes in the Flash array.
A mass erase of the full Flash array is only possible when FPLDIS, FPHDIS, and FPOPEN bits in
the FPROT register are set prior to launching the command.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
562 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.4.1.3.1 Erase Verify Command
The erase verify operation will verify that a Flash array is erased.
An example flow to execute the erase verify operation is shown in Figure 19-25. The erase verify command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the erase verify command.
The address and data written will be ignored.
2. Write the erase verify command, 0x05, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the erase verify
command.
After launching the erase verify command, the CCIF flag in the FSTAT register will set after the operation
has completed unless a new command write sequence has been buffered. Upon completion of the erase
verify operation, the BLANK flag in the FSTAT register will be set if all addresses in the Flash array are
verified to be erased. If any address in the Flash array is not erased, the erase verify operation will terminate
and the BLANK flag in the FSTAT register will remain clear.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 563
Rev 01.24
Figure 19-25. Example Erase Verify Command Flow
Write: Flash Array Address
Write: FCMD register
Erase Verify Command 0x05
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and Dummy Data
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CCIF
Set?
ACCERR/
PVIOL
Set?
no
Erase Verify
Status
yes
EXIT
Flash Array
Not Erased
EXIT
Flash Array
Erased
BLANK
Set?
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
564 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.4.1.3.2 Program Command
The program operation will program a previously erased word in the Flash array using an embedded
algorithm.
An example flow to execute the program operation is shown in Figure 19-26. The program command write
sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the program command. The
data written will be programmed to the Flash array address written.
2. Write the program command, 0x20, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the program
command.
If a word to be programmed is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the program command will not launch. Once the program command has successfully launched,
the CCIF flag in the FSTAT register will set after the program operation has completed unless a new
command write sequence has been buffered. By executing a new program command write sequence on
sequential words after the CBEIF flag in the FSTAT register has been set, up to 55% faster programming
time per word can be effectively achieved than by waiting for the CCIF flag to set after each program
operation.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 565
Rev 01.24
Figure 19-26. Example Program Command Flow
Write: Flash Address
Write: FCMD register
Program Command 0x20
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and program Data
Bit Polling for
Buffer Empty
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
yes
Sequential
Programming
Decision
Next
Word?
no
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
CCIF
Set?
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
566 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.4.1.3.3 Sector Erase Command
The sector erase operation will erase all addresses in a 1024 byte sector of the Flash array using an
embedded algorithm.
An example flow to execute the sector erase operation is shown in Figure 19-27. The sector erase
command write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the sector erase command.
The Flash address written determines the sector to be erased while MCU address bits [9:0] and the
data written are ignored.
2. Write the sector erase command, 0x40, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the sector erase
command.
If a Flash sector to be erased is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the sector erase command will not launch. Once the sector erase command has successfully
launched, the CCIF flag in the FSTAT register will set after the sector erase operation has completed unless
a new command write sequence has been buffered.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 567
Rev 01.24
Figure 19-27. Example Sector Erase Command Flow
Write: Flash Sector Address
Write: FCMD register
Sector Erase Command 0x40
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
568 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.4.1.3.4 Mass Erase Command
The mass erase operation will erase all addresses in a Flash array using an embedded algorithm.
An example flow to execute the mass erase operation is shown in Figure 19-28. The mass erase command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the mass erase command.
The address and data written will be ignored.
2. Write the mass erase command, 0x41, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the mass erase
command.
If a Flash array to be erased contains any protected area, the PVIOL flag in the FSTAT register will set and
the mass erase command will not launch. Once the mass erase command has successfully launched, the
CCIF flag in the FSTAT register will set after the mass erase operation has completed unless a new
command write sequence has been buffered.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 569
Rev 01.24
Figure 19-28. Example Mass Erase Command Flow
Write: Flash Block Address
Write: FCMD register
Mass Erase Command 0x41
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
570 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
19.4.1.4 Illegal Flash Operations
19.4.1.4.1 Access Error
The ACCERR flag in the FSTAT register will be set during the command write sequence if any of the
following illegal Flash operations are performed causing the command write sequence to immediately
abort:
1. Writing to the Flash address space before initializing the FCLKDIV register
2. Writing a misaligned word or a byte to the valid Flash address space
3. Writing to the Flash address space while CBEIF is not set
4. Writing a second word to the Flash address space before executing a program or erase command
on the previously written word
5. Writing to any Flash register other than FCMD after writing a word to the Flash address space
6. Writing a second command to the FCMD register before executing the previously written
command
7. Writing an invalid command to the FCMD register
8. Writing to any Flash register other than FSTAT (to clear CBEIF) after writing to the FCMD register
9. The part enters stop mode and a program or erase command is in progress. The command is aborted
and any pending command is killed
10. When security is enabled, a command other than mass erase originating from a non-secure memory
or from the background debug mode is written to the FCMD register
11. A 0 is written to the CBEIF bit in the FSTAT register to abort a command write sequence.
The ACCERR flag will not be set if any Flash register is read during the command write sequence. If the
Flash array is read during execution of an algorithm (CCIF=0), the Flash module will return invalid data
and the ACCERR flag will not be set. If an ACCERR flag is set in the FSTAT register, the Flash command
controller is locked. It is not possible to launch another command until the ACCERR flag is cleared.
19.4.1.4.2 Protection Violation
The PVIOL flag in the FSTAT register will be set during the command write sequence after the word write
to the Flash address space if any of the following illegal Flash operations are performed, causing the
command write sequence to immediately abort:
1. Writing a Flash address to program in a protected area of the Flash array (see Section 19.3.2.5).
2. Writing a Flash address to erase in a protected area of the Flash array.
3. Writing the mass erase command to the FCMD register while any protection is enabled.
If the PVIOL flag is set, the Flash command controller is locked. It is not possible to launch another
command until the PVIOL flag is cleared.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 571
Rev 01.24
19.4.2 Operating Modes
19.4.2.1 Wait Mode
If the MCU enters wait mode while a Flash command is active (CCIF = 0), that command and any buffered
command will be completed.
The Flash module can recover the MCU from wait mode if the interrupts are enabled (see Section 19.4.5).
19.4.2.2 Stop Mode
If the MCU enters stop mode while a Flash command is active (CCIF = 0), that command will be aborted
and the data being programmed or erased is lost. The high voltage circuitry to the Flash array will be
switched off when entering stop mode. CCIF and ACCERR flags will be set. Upon exit from stop mode,
the CBEIF flag will be set and any buffered command will not be executed. The ACCERR flag must be
cleared before returning to normal operation.
NOTE
As active Flash commands are immediately aborted when the MCU enters
stop mode, it is strongly recommended that the user does not use the STOP
instruction during program and erase execution.
19.4.2.3 Background Debug Mode
In background debug mode (BDM), the FPROT register is writable. If the MCU is unsecured, then all
Flash commands listed in Table 19-17 can be executed. If the MCU is secured and is in special single chip
mode, the only possible command to execute is mass erase.
19.4.3 Flash Module Security
The Flash module provides the necessary security information to the MCU. After each reset, the Flash
module determines the security state of the MCU as defined in Section 19.3.2.2, “Flash Security Register
(FSEC)”.
The contents of the Flash security/options byte at address 0xFF0F in the Flash configuration field must be
changed directly by programming address 0xFF0F when the device is unsecured and the higher address
sector is unprotected. If the Flash security/options byte is left in the secure state, any reset will cause the
MCU to return to the secure operating mode.
19.4.3.1 Unsecuring the MCU using Backdoor Key Access
The MCU may only be unsecured by using the backdoor key access feature which requires knowledge of
the contents of the backdoor key (four 16-bit words programmed at addresses 0xFF00–0xFF07). If
KEYEN[1:0] = 1:0 and the KEYACC bit is set, a write to a backdoor key address in the Flash array triggers
a comparison between the written data and the backdoor key data stored in the Flash array. If all four words
of data are written to the correct addresses in the correct order and the data matches the backdoor key
stored in the Flash array, the MCU will be unsecured. The data must be written to the backdoor key
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
572 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
addresses sequentially staring with 0xFF00-0xFF01 and ending with 0xFF06–0xFF07. The values 0x0000
and 0xFFFF are not permitted as keys. When the KEYACC bit is set, reads of the Flash array will return
invalid data.
The user code stored in the Flash array must have a method of receiving the backdoor key from an external
stimulus. This external stimulus would typically be through one of the on-chip serial ports.
If KEYEN[1:0] = 1:0 in the FSEC register, the MCU can be unsecured by the backdoor key access
sequence described below:
1. Set the KEYACC bit in the FCNFG register
2. Write the correct four 16-bit words to Flash addresses 0xFF00–0xFF07 sequentially starting with
0xFF00
3. Clear the KEYACC bit in the FCNFG register
4. If all four 16-bit words match the backdoor key stored in Flash addresses 0xFF00–0xFF07, the
MCU is unsecured and bits SEC[1:0] in the FSEC register are forced to the unsecure state of 1:0
The backdoor key access sequence is monitored by the internal security state machine. An illegal operation
during the backdoor key access sequence will cause the security state machine to lock, leaving the MCU
in the secured state. A reset of the MCU will cause the security state machine to exit the lock state and
allow a new backdoor key access sequence to be attempted. The following illegal operations will lock the
security state machine:
1. If any of the four 16-bit words does not match the backdoor key programmed in the Flash array
2. If the four 16-bit words are written in the wrong sequence
3. If more than four 16-bit words are written
4. If any of the four 16-bit words written are 0x0000 or 0xFFFF
5. If the KEYACC bit does not remain set while the four 16-bit words are written
After the backdoor key access sequence has been correctly matched, the MCU will be unsecured. The
Flash security byte can be programmed to the unsecure state, if desired.
In the unsecure state, the user has full control of the contents of the four word backdoor key by
programming bytes 0xFF00–0xFF07 of the Flash configuration field.
The security as defined in the Flash security/options byte at address 0xFF0F is not changed by using the
backdoor key access sequence to unsecure. The backdoor key stored in addresses 0xFF00–0xFF07 is
unaffected by the backdoor key access sequence. After the next reset sequence, the security state of the
Flash module is determined by the Flash security/options byte at address 0xFF0F. The backdoor key access
sequence has no effect on the program and erase protection defined in the FPROT register.
It is not possible to unsecure the MCU in special single chip mode by executing the backdoor key access
sequence in background debug mode.
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 573
Rev 01.24
19.4.4 Flash Reset Sequence
On each reset, the Flash module executes a reset sequence to hold CPU activity while loading the following
registers from the Flash array memory according to Table 19-1:
• FPROT — Flash Protection Register (see Section 19.3.2.5)
• FSEC — Flash Security Register (see Section 19.3.2.2)
19.4.4.1 Reset While Flash Command Active
If a reset occurs while any Flash command is in progress, that command will be immediately aborted. The
state of the word being programmed or the sector/array being erased is not guaranteed.
19.4.5 Interrupts
The Flash module can generate an interrupt when all Flash commands have completed execution or the
Flash address, data, and command buffers are empty.
NOTE
Vector addresses and their relative interrupt priority are determined at the
MCU level.
19.4.5.1 Description of Interrupt Operation
Figure 19-29 shows the logic used for generating interrupts.
The Flash module uses the CBEIF and CCIF flags in combination with the enable bits CBIE and CCIE to
discriminate for the generation of interrupts.
Figure 19-29. Flash Interrupt Implementation
For a detailed description of these register bits, refer to Section 19.3.2.4, “Flash Configuration Register
(FCNFG)” and Section 19.3.2.6, “Flash Status Register (FSTAT)”.
Table 19-18. Flash Interrupt Sources
Interrupt Source Interrupt Flag Local Enable Global (CCR) Mask
Flash Address, Data, and Command
Buffers are empty
CBEIF
(FSTAT register)
CBEIE I Bit
All Flash commands have completed
execution
CCIF
(FSTAT register)
CCIE I Bit
CBEIF
CBEIE
CCIF
CCIE
FLASH INTERRUPT REQUEST
Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
574 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 575
Rev 01.24
Chapter 20
96 Kbyte Flash Module (S12FTS96KV1)
20.1 Introduction
The FTS128K1FTS96K module implements a 12896 Kbyte Flash (nonvolatile) memory. The Flash
memory contains one array of 12896 Kbytes organized as 1024768 rows of 128128 bytes with an erase
sector size of eight rows (10241024 bytes). The Flash array may be read as either bytes, aligned words, or
misaligned words. Read access time is one bus cycle for byte and aligned word, and two bus cycles for
misaligned words.
The Flash array is ideal for program and data storage for single-supply applications allowing for field
reprogramming without requiring external voltage sources for program or erase. Program and erase
functions are controlled by a command driven interface. The Flash module supports both mass erase and
sector erase. An erased bit reads 1 and a programmed bit reads 0. The high voltage required to program
and erase is generated internally. It is not possible to read from a Flash array while it is being erased or
programmed.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
20.1.1 Glossary
Command Write Sequence — A three-step MCU instruction sequence to program, erase, or erase verify
the Flash array memory.
20.1.2 Features
•12896 Kbytes of Flash memory comprised of one 12896 Kbyte array divided into 12896 sectors of
10241024 bytes
• Automated program and erase algorithm
• Interrupts on Flash command completion and command buffer empty
• Fast sector erase and word program operation
• 2-stage command pipeline for faster multi-word program times
• Flexible protection scheme to prevent accidental program or erase
• Single power supply for Flash program and erase operations
• Security feature to prevent unauthorized access to the Flash array memory
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
576 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.1.3 Modes of Operation
See Section 20.4.2, “Operating Modes” for a description of the Flash module operating modes. For
program and erase operations, refer to Section 20.4.1, “Flash Command Operations”.
20.1.4 Block Diagram
Figure 20-1Figure 20-2 shows a block diagram of the FTS128K1FTS96K module.
Figure 20-1. FTS128K1 Block Diagram
FTS128K1
Oscillator
Clock
Command
Complete
Interrupt
Command
Buffer Empty
Interrupt
Flash Array
64K * 16 Bits
sector 0
sector 1
sector 127
Clock
Divider FCLK
Protection
Security
Command Pipeline
cmd2
addr2
data2
cmd1
addr1
data1
Registers
Flash
Interface
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 577
Rev 01.24
Figure 20-2. FTS96K Block Diagram
20.2 External Signal Description
The FTS128K1FTS96K module contains no signals that connect off-chip.
20.3 Memory Map and Registers
This section describes the FTS128K1FTS96K memory map and registers.
20.3.1 Module Memory Map
The FTS128K1FTS96K memory map is shown in Figure 20-3Figure 20-4. The HCS12 architecture places
the Flash array addresses between 0x40000x4000 and 0xFFFF, which corresponds to three 16 Kbyte
pages. The content of the HCS12 Core PPAGE register is used to map the logical middle page ranging from
FTS96K
Oscillator
Clock
Command
Complete
Interrupt
Command
Buffer Empty
Interrupt
Flash Array
48K * 16 Bits
sector 0
sector 1
sector 95
Clock
Divider FCLK
Protection
Security
Command Pipeline
cmd2
addr2
data2
cmd1
addr1
data1
Registers
Flash
Interface
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
578 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
address 0x8000 to 0xBFFF to any physical 16K byte page in the Flash array memory.1The FPROT register
(see Section 20.3.2.5) can be set to globally protect the entire Flash array. Three separate areas, one starting
from the Flash array starting address (called lower) towards higher addresses, one growing downward from
the Flash array end address (called higher), and the remaining addresses, can be activated for protection.
The Flash array addresses covered by these protectable regions are shown in Figure 20-3Figure 20-4. The
higher address area is mainly targeted to hold the boot loader code since it covers the vector space. The
lower address area can be used for EEPROM emulation in an MCU without an EEPROM module since it
can be left unprotected while the remaining addresses are protected from program or erase. Default
protection settings as well as security information that allows the MCU to restrict access to the Flash
module are stored in the Flash configuration field described in Table 20-1.
1. By placing 0x3E/0x3F in the HCS12 Core PPAGE register, the bottom/top fixed 16 Kbyte pagescan be seen twice in the MCU
memory map.
Table 20-1. Flash Configuration Field
Flash Address Size
(bytes) Description
0xFF00–0xFF07 8 Backdoor Key to unlock security
0xFF08–0xFF0C 5 Reserved
0xFF0D 1 Flash Protection byte
Refer to Section 20.3.2.5, “Flash Protection Register (FPROT)”
0xFF0E 1 Reserved
0xFF0F 1 Flash Security/Options byte
Refer to Section 20.3.2.2, “Flash Security Register (FSEC)”
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 579
Rev 01.24
Figure 20-3. Flash Memory Map
Flash Registers
MODULE BASE + 0x0000
0xFF00–0xFF0F (Flash Configuration Field)
MODULE BASE + 0x000F
0x8000
Flash Protected Low Sectors
1, 2, 4, 8 Kbytes
FLASH_START = 0x4000
0x5000
0x4400
0x6000
16K PAGED
MEMORY
0x38 0x39 0x3A 0x3B
0x3E
0x3C 0x3D 003E 0x3F
Note: 0x38–0x3F correspond to the PPAGE register content
FLASH_END = 0xFFFF
0xF800
0xF000
0xC000
0xE000 Flash Protected High Sectors
2, 4, 8, 16 Kbytes
0x3F
0x4800
Flash Array
16 bytes
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
580 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 20-4. Flash Memory Map
Flash Registers
MODULE BASE + 0x0000
0xFF00–0xFF0F (Flash Configuration Field)
MODULE BASE + 0x000F
0x8000
Flash Protected Low Sectors
1, 2, 4, 8 Kbytes
FLASH_START = 0x4000
0x5000
0x4400
0x6000
16K PAGED
MEMORY
0x3A 0x3B
0x3E
0x3C 0x3D 003E 0x3F
Note: 0x3A–0x3F correspond to the PPAGE register content
FLASH_END = 0xFFFF
0xF800
0xF000
0xC000
0xE000 Flash Protected High Sectors
2, 4, 8, 16 Kbytes
0x3F
0x4800
Flash Array
16 bytes
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 581
Rev 01.24
Table 20-2. Flash Array Memory Map Summary
MCU Address
Range PPAGE Protectable
Low Range
Protectable
High Range
Array Relative
Address(1)
1. Inside Flash block.
0x0000–0x3FFF(2)
2. If allowed by MCU.
Unpaged
(0x3D)
N.A. N.A. 0x14000–0x17FFF
0x4000–0x7FFF Unpaged
(0x3E)
0x4000–0x43FF N.A. 0x18000–0x1BFFF
0x4000–0x47FF
0x4000–0x4FFF
0x4000–0x5FFF
0x8000–0xBFFF 0x38 N.A. N.A. 0x00000–0x03FFF
0x39 N.A. N.A. 0x04000–0x07FFF
0x3A N.A. N.A. 0x08000–0x0BFFF
0x3B N.A. N.A. 0x0C000–0x0FFFF
0x3C N.A. N.A. 0x10000–0x13FFF
0x3D N.A. N.A. 0x14000–0x17FFF
0x3E 0x8000–0x83FF N.A. 0x18000–0x1BFFF
0x8000–0x87FF
0x8000–0x8FFF
0x8000–0x9FFF
0x3F N.A. 0xB800–0xBFFF 0x1C000–0x1FFFF
0xB000–0xBFFF
0xA000–0xBFFF
0x8000–0xBFFF
0xC000–0xFFFF Unpaged
(0x3F)
N.A. 0xF800–0xFFFF 0x1C000–0x1FFFF
0xF000–0xFFFF
0xE000–0xFFFF
0xC000–0xFFFF
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
582 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Table 20-3. Flash Array Memory Map Summary
MCU Address
Range PPAGE Protectable
Low Range
Protectable
High Range
Array Relative
Address(1)
1. Inside Flash block.
0x0000–0x3FFF(2)
2. If allowed by MCU.
Unpaged
(0x3D)
N.A. N.A. 0x14000–0x17FFF
0x4000–0x7FFF Unpaged
(0x3E)
0x4000–0x43FF N.A. 0x18000–0x1BFFF
0x4000–0x47FF
0x4000–0x4FFF
0x4000–0x5FFF
0x8000–0xBFFF 0x3A N.A. N.A. 0x08000–0x0BFFF
0x3B N.A. N.A. 0x0C000–0x0FFFF
0x3C N.A. N.A. 0x10000–0x13FFF
0x3D N.A. N.A. 0x14000–0x17FFF
0x3E 0x8000–0x83FF N.A. 0x18000–0x1BFFF
0x8000–0x87FF
0x8000–0x8FFF
0x8000–0x9FFF
0x3F N.A. 0xB800–0xBFFF 0x1C000–0x1FFFF
0xB000–0xBFFF
0xA000–0xBFFF
0x8000–0xBFFF
0xC000–0xFFFF Unpaged
(0x3F)
N.A. 0xF800–0xFFFF 0x1C000–0x1FFFF
0xF000–0xFFFF
0xE000–0xFFFF
0xC000–0xFFFF
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 583
Rev 01.24
20.3.2 Register Descriptions
The Flash module contains a set of 16 control and status registers located between module base + 0x0000
and 0x000F. A summary of the Flash module registers is given in Figure 20-5. Detailed descriptions of
each register bit are provided.
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000
FCLKDIV
R FDIVLD PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
0x0001
FSEC
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
0x0002
RESERVED1
(1)
1. Intended for factory test purposes only.
R00000000
W
0x0003
FCNFG
RCBEIE CCIE KEYACC 00000
W
0x0004
FPROT
RFPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
0x0005
FSTAT
RCBEIF CCIF PVIOL ACCERR 0 BLANK FAIL DONE
W
0x0006
FCMD
R0 CMDB6 CMDB5 00
CMDB2 0CMDB0
W
0x0007
RESERVED21
R00000000
W
0x0008
FADDRHI1
RFABHI
W
0x0009
FADDRLO1
RFABLO
W
0x000A
FDATAHI1
RFDHI
W
0x000B
FDATALO1
RFDLO
W
0x000C
RESERVED31
R00000000
W
0x000D
RESERVED41
R00000000
W
0x000E
RESERVED51
R00000000
W
0x000F
RESERVED61
R00000000
W
= Unimplemented or Reserved
Figure 20-5. Flash Register Summary
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
584 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.3.2.1 Flash Clock Divider Register (FCLKDIV)
The FCLKDIV register is used to control timed events in program and erase algorithms.
All bits in the FCLKDIV register are readable, bits 6–0 are write once and bit 7 is not writable.
20.3.2.2 Flash Security Register (FSEC)
The FSEC register holds all bits associated with the security of the MCU and Flash module.
All bits in the FSEC register are readable but not writable.
The FSEC register is loaded from the Flash configuration field at 0xFF0F during the reset sequence,
indicated by F in Figure 20-7.
Module Base + 0x0000
76543210
R FDIVLD
PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-6. Flash Clock Divider Register (FCLKDIV)
Table 20-4. FCLKDIV Field Descriptions
Field Description
7
FDIVLD
Clock Divider Loaded
0 FCLKDIV register has not been written
1 FCLKDIV register has been written to since the last reset
6
PRDIV8
Enable Prescalar by 8
0 The oscillator clock is directly fed into the Flash clock divider
1 The oscillator clock is divided by 8 before feeding into the Flash clock divider
5–0
FDIV[5:0]
Clock Divider Bits — The combination of PRDIV8 and FDIV[5:0] must divide the oscillator clock down to a
frequency of 150 kHz – 200 kHz. The maximum divide ratio is 512. Refer to Section 20.4.1.1, “Writing the
FCLKDIV Register” for more information.
Module Base + 0x0001
76543210
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
Reset F F FFFFFF
= Unimplemented or Reserved
Figure 20-7. Flash Security Register (FSEC)
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 585
Rev 01.24
The security function in the Flash module is described in Section 20.4.3, “Flash Module Security”.
20.3.2.3 RESERVED1
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
Table 20-5. FSEC Field Descriptions
Field Description
7–6
KEYEN[1:0]
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of the backdoor key access
to the Flash module as shown in Table 20-6.
5–2
NV[5:2]
Nonvolatile Flag Bits — The NV[5:2] bits are available to the user as nonvolatile flags.
1–0
SEC[1:0]
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in Table 20-7. If the
Flash module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
Table 20-6. Flash KEYEN States
KEYEN[1:0] Status of Backdoor Key Access
00 DISABLED
01(1)
1. Preferred KEYEN state to disable Backdoor Key Access.
DISABLED
10 ENABLED
11 DISABLED
Table 20-7. Flash Security States
SEC[1:0] Status of Security
00 Secured
01(1)
1. Preferred SEC state to set MCU to secured state.
Secured
10 Unsecured
11 Secured
Module Base + 0x0002
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-8. RESERVED1
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
586 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.3.2.4 Flash Configuration Register (FCNFG)
The FCNFG register enables the Flash interrupts and gates the security backdoor key writes.
CBEIE, CCIE, and KEYACC are readable and writable while remaining bits read 0 and are not writable.
KEYACC is only writable if the KEYEN bit in the FSEC register is set to the enabled state (see Section
20.3.2.2).
20.3.2.5 Flash Protection Register (FPROT)
The FPROT register defines which Flash sectors are protected against program or erase.
The FPROT register is readable in normal and special modes. FPOPEN can only be written from a 1 to a 0.
FPLS[1:0] can be written anytime until FPLDIS is cleared. FPHS[1:0] can be written anytime until
Module Base + 0x0003
76543210
R
CBEIE CCIE KEYACC
00000
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-9. Flash Configuration Register (FCNFG)
Table 20-8. FCNFG Field Descriptions
Field Description
7
CBEIE
Command Buffer Empty Interrupt Enable — The CBEIE bit enables the interrupts in case of an empty
command buffer in the Flash module.
0 Command Buffer Empty interrupts disabled
1 An interrupt will be requested whenever the CBEIF flag is set (see Section 20.3.2.6)
6
CCIE
Command Complete Interrupt Enable — The CCIE bit enables the interrupts in case of all commands being
completed in the Flash module.
0 Command Complete interrupts disabled
1 An interrupt will be requested whenever the CCIF flag is set (see Section 20.3.2.6)
5
KEYACC
Enable Security Key Writing.
0 Flash writes are interpreted as the start of a command write sequence
1 Writes to the Flash array are interpreted as a backdoor key while reads of the Flash array return invalid data
Module Base + 0x0004
76543210
R
FPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
Reset F F FFFFFF
Figure 20-10. Flash Protection Register (FPROT)
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 587
Rev 01.24
FPHDIS is cleared. The FPROT register is loaded from Flash address 0xFF0D during the reset sequence,
indicated by F in Figure 20-10.
To change the Flash protection that will be loaded on reset, the upper sector of the Flash array must be
unprotected, then the Flash protection byte located at Flash address 0xFF0D must be written to.
A protected Flash sector is disabled by FPHDIS and FPLDIS while the size of the protected sector is
defined by FPHS[1:0] and FPLS[1:0] in the FPROT register.
Trying to alter any of the protected areas will result in a protect violation error and the PVIOL flag will be
set in the FSTAT register (see Section 20.3.2.6). A mass erase of the whole Flash array is only possible
when protection is fully disabled by setting the FPOPEN, FPLDIS, and FPHDIS bits. An attempt to mass
erase a Flash array while protection is enabled will set the PVIOL flag in the FSTAT register.
Table 20-9. FPROT Field Descriptions
Field Description
7
FPOPEN
Protection Function for Program or Erase — It is possible using the FPOPEN bit to either select address
ranges to be protected using FPHDIS, FPLDIS, FPHS[1:0] and FPLS[1:0] or to select the same ranges to be
unprotected. When FPOPEN is set, FPxDIS enables the ranges to be protected, whereby clearing FPxDIS
enables protection for the range specified by the corresponding FPxS[1:0] bits. When FPOPEN is cleared,
FPxDIS defines unprotected ranges as specified by the corresponding FPxS[1:0] bits. In this case, setting
FPxDIS enables protection. Thus the effective polarity of the FPxDIS bits is swapped by the FPOPEN bit as
shown in Table 20-10. This function allows the main part of the Flash array to be protected while a small range
can remain unprotected for EEPROM emulation.
0 The FPHDIS and FPLDIS bits define Flash address ranges to be unprotected
1 The FPHDIS and FPLDIS bits define Flash address ranges to be protected
6
NV6
Nonvolatile Flag Bit — The NV6 bit should remain in the erased state for future enhancements.
5
FPHDIS
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in the higher space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
4–3
FPHS[1:0]
Flash Protection Higher Address Size — The FPHS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 20-11. The FPHS[1:0] bits can only be written to while the FPHDIS bit is set.
2
FPLDIS
Flash Protection Lower Address Range Disable — The FPLDIS bit determines whether there is a
protected/unprotected sector in the lower space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
1–0
FPLS[1:0]
Flash Protection Lower Address Size — The FPLS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 20-12. The FPLS[1:0] bits can only be written to while the FPLDIS bit is set.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
588 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 20-11 illustrates all possible protection scenarios. Although the protection scheme is loaded from
the Flash array after reset, it is allowed to change in normal modes. This protection scheme can be used by
applications requiring re-programming in single chip mode while providing as much protection as possible
if no re-programming is required.
Table 20-10. Flash Protection Function
FPOPEN FPHDIS FPHS[1] FPHS[0] FPLDIS FPLS[1] FPLS[0] Function(1)
1. For range sizes refer to Table 20-11 and Table 20-12 or .
1 1 x x 1 x x No protection
1 1 x x 0 x x Protect low range
1 0 x x 1 x x Protect high range
1 0 x x 0 x x Protect high and low ranges
0 1 x x 1 x x Full Flash array protected
0 0 x x 1 x x Unprotected high range
0 1 x x 0 x x Unprotected low range
0 0 x x 0 x x Unprotected high and low ranges
Table 20-11. Flash Protection Higher Address Range
FPHS[1:0] Address Range Range Size
00 0xF800–0xFFFF 2 Kbytes
01 0xF000–0xFFFF 4 Kbytes
10 0xE000–0xFFFF 8 Kbytes
11 0xC000–0xFFFF 16 Kbytes
Table 20-12. Flash Protection Lower Address Range
FPLS[1:0] Address Range Range Size
00 0x4000–0x43FF 1 Kbyte
01 0x4000–0x47FF 2 Kbytes
10 0x4000–0x4FFF 4 Kbytes
11 0x4000–0x5FFF 8 Kbytes
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 589
Rev 01.24
Figure 20-11. Flash Protection Scenarios
20.3.2.5.1 Flash Protection Restrictions
The general guideline is that protection can only be added, not removed. All valid transitions between
Flash protection scenarios are specified in Table 20-13. Any attempt to write an invalid scenario to the
FPROT register will be ignored and the FPROT register will remain unchanged. The contents of the
FPROT register reflect the active protection scenario.
Table 20-13. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
0 XXXX
1XX
2XX
3X
4XX
5 XXXX
7654
FPOPEN = 1
3210
FPHS[1:0] FPLS[1:0]
FPOPEN = 0
FPHDIS = 1
FPLDIS = 1
FPHDIS = 1
FPLDIS = 0
FPHDIS = 0
FPLDIS = 1
FPHDIS = 0
FPLDIS = 0
Scenario
Scenario
Protected Flash
FPHS[1:0] FPLS[1:0]
0xFFFF
0xFFFF
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
590 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.3.2.6 Flash Status Register (FSTAT)
The FSTAT register defines the status of the Flash command controller and the results of command
execution.
In normal modes, bits CBEIF, PVIOL, and ACCERR are readable and writable, bits CCIF and BLANK
are readable and not writable, remaining bits, including FAIL and DONE, read 0 and are not writable. In
special modes, FAIL is readable and writable while DONE is readable but not writable. FAIL must be clear
in special modes when starting a command write sequence.
6XXXX
7 XXXXXXXX
1. Allowed transitions marked with X.
Module Base + 0x0005
76543210
R
CBEIF
CCIF
PVIOL ACCERR
0 BLANK
FAIL
DONE
W
Reset 11000001
= Unimplemented or Reserved
Figure 20-12. Flash Status Register (FSTAT)
Table 20-14. FSTAT Field Descriptions
Field Description
7
CBEIF
Command Buffer Empty Interrupt Flag — The CBEIF flag indicates that the address, data and command
buffers are empty so that a new command write sequence can be started. The CBEIF flag is cleared by writing
a 1 to CBEIF. Writing a 0 to the CBEIF flag has no effect on CBEIF. Writing a 0 to CBEIF after writing an aligned
word to the Flash address space but before CBEIF is cleared will abort a command write sequence and cause
the ACCERR flag in the FSTAT register to be set. Writing a 0 to CBEIF outside of a command write sequence
will not set the ACCERR flag. The CBEIF flag is used together with the CBEIE bit in the FCNFG register to
generate an interrupt request (see Figure 20-28).
0 Buffers are full
1 Buffers are ready to accept a new command
6
CCIF
Command Complete Interrupt Flag — The CCIF flag indicates that there are no more commands pending. The
CCIF flag is cleared when CBEIF is clear and sets automatically upon completion of all active and pending
commands. The CCIF flag does not set when an active commands completes and a pending command is
fetched from the command buffer. Writing to the CCIF flag has no effect. The CCIF flag is used together with the
CCIE bit in the FCNFG register to generate an interrupt request (see Figure 20-28).
0 Command in progress
1 All commands are completed
Table 20-13. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 591
Rev 01.24
20.3.2.7 Flash Command Register (FCMD)
The FCMD register defines the Flash commands.
Bits CMDB6, CMDB5, CMDB2, and CMDB0 are readable and writable during a command write
sequence while bits 7, 4, 3, and 1 read 0 and are not writable.
5
PVIOL
Protection Violation — The PVIOL flag indicates an attempt was made to program or erase an address in a
protected Flash array memory area. The PVIOL flag is cleared by writing a 1 to PVIOL. Writing a 0 to the PVIOL
flag has no effect on PVIOL. While PVIOL is set, it is not possible to launch another command.
0 No protection violation detected
1 Protection violation has occurred
4
ACCERR
Access Error — The ACCERR flag indicates an illegal access to the Flash array caused by either a violation of
the command write sequence, issuing an illegal command (illegal combination of the CMDBx bits in the FCMD
register) or the execution of a CPU STOP instruction while a command is executing (CCIF=0). The ACCERR flag
is cleared by writing a 1 to ACCERR. Writing a 0 to the ACCERR flag has no effect on ACCERR. While ACCERR
is set, it is not possible to launch another command.
0 No access error detected
1 Access error has occurred
2
BLANK
Flash Array Has Been Verified as Erased — The BLANK flag indicates that an erase verify command has
checked the Flash array and found it to be erased. The BLANK flag is cleared by hardware when CBEIF is
cleared as part of a new valid command write sequence. Writing to the BLANK flag has no effect on BLANK.
0 If an erase verify command has been requested, and the CCIF flag is set, then a 0 in BLANK indicates the
array is not erased
1 Flash array verifies as erased
1
FAIL
Flag Indicating a Failed Flash Operation — In special modes, the FAIL flag will set if the erase verify operation
fails (Flash array verified as not erased). Writing a 0 to the FAIL flag has no effect on FAIL. The FAIL flag is cleared
by writing a 1 to FAIL. While FAIL is set, it is not possible to launch another command.
0 Flash operation completed without error
1 Flash operation failed
0
DONE
Flag Indicating a Failed Operation is not Active — In special modes, the DONE flag will clear if a program,
erase, or erase verify operation is active.
0 Flash operation is active
1 Flash operation is not active
Module Base + 0x0006
76543210
R0
CMDB6 CMDB5
00
CMDB2
0
CMDB0
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-13. Flash Command Register (FCMD)
Table 20-14. FSTAT Field Descriptions
Field Description
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
592 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.3.2.8 RESERVED2
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
20.3.2.9 Flash Address Register (FADDR)
FADDRHI and FADDRLO are the Flash address registers.
\
\
\
Table 20-15. FCMD Field Descriptions
Field Description
6, 5, 2, 0
CMDB[6:5]
CMDB[2]
CMDB[0]
Valid Flash commands are shown in Table 20-16. An attempt to execute any command other than those listed in
Table 20-16 will set the ACCERR bit in the FSTAT register (see Section 20.3.2.6).
Table 20-16. Valid Flash Command List
CMDB NVM Command
0x05 Erase verify
0x20 Word program
0x40 Sector erase
0x41 Mass erase
Module Base + 0x0007
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-14. RESERVED2
Module Base + 0x0008
76543210
R
FABHI
W
Reset 00000000
Figure 20-15. Flash Address High Register (FADDRHI)
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 593
Rev 01.24
In normal modes, all FABHI and FABLO bits read 0 and are not writable. In special modes, the FABHI
and FABLO bits are readable and writable. For sector erase, the MCU address bits [9:0] are ignored.For
mass erase, any address within the Flash array is valid to start the command.
20.3.2.10 Flash Data Register (FDATA)
FDATAHI and FDATALO are the Flash data registers.
In normal modes, all FDATAHI and FDATALO bits read 0 and are not writable. In special modes, all
FDATAHI and FDATALO bits are readable and writable when writing to an address within the Flash
address range.
20.3.2.11 RESERVED3
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x0009
76543210
R
FABLO
W
Reset 00000000
Figure 20-16. Flash Address Low Register (FADDRLO)
Module Base + 0x000A
76543210
R
FDHI
W
Reset 00000000
Figure 20-17. Flash Data High Register (FDATAHI)
Module Base + 0x000B
76543210
R
FDLO
W
Reset 00000000
Figure 20-18. Flash Data Low Register (FDATALO)
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
594 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
All bits read 0 and are not writable.
20.3.2.12 RESERVED4
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
20.3.2.13 RESERVED5
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
20.3.2.14 RESERVED6
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x000C
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-19. RESERVED3
Module Base + 0x000D
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-20. RESERVED4
Module Base + 0x000E
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-21. RESERVED5
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 595
Rev 01.24
All bits read 0 and are not writable.
20.4 Functional Description
20.4.1 Flash Command Operations
Write operations are used for the program, erase, and erase verify algorithms described in this section. The
program and erase algorithms are controlled by a state machine whose timebase FCLK is derived from the
oscillator clock via a programmable divider. The FCMD register as well as the associated FADDR and
FDATA registers operate as a buffer and a register (2-stage FIFO) so that a new command along with the
necessary data and address can be stored to the buffer while the previous command is still in progress. This
pipelined operation allows a time optimization when programming more than one word on a specific row,
as the high voltage generation can be kept active in between two programming commands. The pipelined
operation also allows a simplification of command launching. Buffer empty as well as command
completion are signalled by flags in the FSTAT register with corresponding interrupts generated, if
enabled.
The next sections describe:
• How to write the FCLKDIV register
• Command write sequence used to program, erase or erase verify the Flash array
• Valid Flash commands
• Errors resulting from illegal Flash operations
20.4.1.1 Writing the FCLKDIV Register
Prior to issuing any Flash command after a reset, it is first necessary to write the FCLKDIV register to
divide the oscillator clock down to within the 150-kHz to 200-kHz range. Since the program and erase
timings are also a function of the bus clock, the FCLKDIV determination must take this information into
account.
If we define:
• FCLK as the clock of the Flash timing control block
• Tbus as the period of the bus clock
• INT(x) as taking the integer part of x (e.g., INT(4.323) = 4),
Module Base + 0x000F
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 20-22. RESERVED6
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
596 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
then FCLKDIV register bits PRDIV8 and FDIV[5:0] are to be set as described in Figure 20-23.
For example, if the oscillator clock frequency is 950 kHz and the bus clock is 10 MHz, FCLKDIV bits
FDIV[5:0] should be set to 4 (000100) and bit PRDIV8 set to 0. The resulting FCLK is then 190 kHz. As
a result, the Flash algorithm timings are increased over optimum target by:
Command execution time will increase proportionally with the period of FCLK.
CAUTION
Because of the impact of clock synchronization on the accuracy of the
functional timings, programming or erasing the Flash array cannot be
performed if the bus clock runs at less than 1 MHz. Programming or erasing
the Flash array with an input clock < 150 kHz should be avoided. Setting
FCLKDIV to a value such that FCLK < 150 kHz can destroy the Flash array
due to overstress. Setting FCLKDIV to a value such that (1/FCLK + Tbus)
< 5µs can result in incomplete programming or erasure of the Flash array
cells.
If the FCLKDIV register is written, the bit FDIVLD is set automatically. If the FDIVLD bit is 0, the
FCLKDIV register has not been written since the last reset. If the FCLKDIV register has not been written
to, the Flash command loaded during a command write sequence will not execute and the ACCERR flag
in the FSTAT register will set.
200 190–()200⁄100×5%=
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 597
Rev 01.24
Figure 20-23. PRDIV8 and FDIV Bits Determination Procedure
PRDIV8=1
yes
no
PRDIV8=0 (reset)
12.8MHz?
FCLK=(PRDCLK)/(1+FDIV[5:0])
PRDCLK=oscillator_clock
PRDCLK=oscillator_clock/8
PRDCLK[MHz]*(5+Tbus[µs]) no
FDIV[5:0]=PRDCLK[MHz]*(5+Tbus[µs])-1
yes
START
Tbus < 1µs?
an integer?
FDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[µs]))
1/FCLK[MHz] + Tbus[µs] > 5
AND
FCLK > 0.15MHz
?
END
yes
no
FDIV[5:0] > 4?
ALL COMMANDS IMPOSSIBLE
yes
no
ALL COMMANDS IMPOSSIBLE
no
TRY TO DECREASE Tbus
yes
oscillator_clock
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
598 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.4.1.2 Command Write Sequence
The Flash command controller is used to supervise the command write sequence to execute program,
erase, and erase verify algorithms.
Before starting a command write sequence, the ACCERR and PVIOL flags in the FSTAT register must be
clear and the CBEIF flag should be tested to determine the state of the address, data, and command buffers.
If the CBEIF flag is set, indicating the buffers are empty, a new command write sequence can be started.
If the CBEIF flag is clear, indicating the buffers are not available, a new command write sequence will
overwrite the contents of the address, data, and command buffers.
A command write sequence consists of three steps which must be strictly adhered to with writes to the
Flash module not permitted between the steps. However, Flash register and array reads are allowed during
a command write sequence. The basic command write sequence is as follows:
1. Write to a valid address in the Flash array memory.
2. Write a valid command to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the command.
The address written in step 1 will be stored in the FADDR registers and the data will be stored in the
FDATA registers. When the CBEIF flag is cleared in step 3, the CCIF flag is cleared by the Flash command
controller indicating that the command was successfully launched. For all command write sequences, the
CBEIF flag will set after the CCIF flag is cleared indicating that the address, data, and command buffers
are ready for a new command write sequence to begin. A buffered command will wait for the active
operation to be completed before being launched. Once a command is launched, the completion of the
command operation is indicated by the setting of the CCIF flag in the FSTAT register. The CCIF flag will
set upon completion of all active and buffered commands.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 599
Rev 01.24
20.4.1.3 Valid Flash Commands
Table 20-17 summarizes the valid Flash commands along with the effects of the commands on the Flash
array.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
Table 20-17. Valid Flash Commands
FCMD Meaning Function on Flash Array
0x05 Erase
Verify
Verify all bytes in the Flash array are erased.
If the Flash array is erased, the BLANK bit will set in the FSTAT register upon command completion.
0x20 Program Program a word (2 bytes) in the Flash array.
0x40 Sector
Erase
Erase all 1024 bytes in a sector of the Flash array.
0x41 Mass
Erase
Erase all bytes in the Flash array.
A mass erase of the full Flash array is only possible when FPLDIS, FPHDIS, and FPOPEN bits in
the FPROT register are set prior to launching the command.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
600 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.4.1.3.1 Erase Verify Command
The erase verify operation will verify that a Flash array is erased.
An example flow to execute the erase verify operation is shown in Figure 20-24. The erase verify command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the erase verify command.
The address and data written will be ignored.
2. Write the erase verify command, 0x05, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the erase verify
command.
After launching the erase verify command, the CCIF flag in the FSTAT register will set after the operation
has completed unless a new command write sequence has been buffered. Upon completion of the erase
verify operation, the BLANK flag in the FSTAT register will be set if all addresses in the Flash array are
verified to be erased. If any address in the Flash array is not erased, the erase verify operation will terminate
and the BLANK flag in the FSTAT register will remain clear.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 601
Rev 01.24
Figure 20-24. Example Erase Verify Command Flow
Write: Flash Array Address
Write: FCMD register
Erase Verify Command 0x05
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and Dummy Data
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CCIF
Set?
ACCERR/
PVIOL
Set?
no
Erase Verify
Status
yes
EXIT
Flash Array
Not Erased
EXIT
Flash Array
Erased
BLANK
Set?
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
602 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.4.1.3.2 Program Command
The program operation will program a previously erased word in the Flash array using an embedded
algorithm.
An example flow to execute the program operation is shown in Figure 20-25. The program command write
sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the program command. The
data written will be programmed to the Flash array address written.
2. Write the program command, 0x20, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the program
command.
If a word to be programmed is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the program command will not launch. Once the program command has successfully launched,
the CCIF flag in the FSTAT register will set after the program operation has completed unless a new
command write sequence has been buffered. By executing a new program command write sequence on
sequential words after the CBEIF flag in the FSTAT register has been set, up to 55% faster programming
time per word can be effectively achieved than by waiting for the CCIF flag to set after each program
operation.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 603
Rev 01.24
Figure 20-25. Example Program Command Flow
Write: Flash Address
Write: FCMD register
Program Command 0x20
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and program Data
Bit Polling for
Buffer Empty
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
yes
Sequential
Programming
Decision
Next
Word?
no
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
CCIF
Set?
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
604 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.4.1.3.3 Sector Erase Command
The sector erase operation will erase all addresses in a 1024 byte sector of the Flash array using an
embedded algorithm.
An example flow to execute the sector erase operation is shown in Figure 20-26. The sector erase
command write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the sector erase command.
The Flash address written determines the sector to be erased while MCU address bits [9:0] and the
data written are ignored.
2. Write the sector erase command, 0x40, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the sector erase
command.
If a Flash sector to be erased is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the sector erase command will not launch. Once the sector erase command has successfully
launched, the CCIF flag in the FSTAT register will set after the sector erase operation has completed unless
a new command write sequence has been buffered.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 605
Rev 01.24
Figure 20-26. Example Sector Erase Command Flow
Write: Flash Sector Address
Write: FCMD register
Sector Erase Command 0x40
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
606 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.4.1.3.4 Mass Erase Command
The mass erase operation will erase all addresses in a Flash array using an embedded algorithm.
An example flow to execute the mass erase operation is shown in Figure 20-27. The mass erase command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the mass erase command.
The address and data written will be ignored.
2. Write the mass erase command, 0x41, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the mass erase
command.
If a Flash array to be erased contains any protected area, the PVIOL flag in the FSTAT register will set and
the mass erase command will not launch. Once the mass erase command has successfully launched, the
CCIF flag in the FSTAT register will set after the mass erase operation has completed unless a new
command write sequence has been buffered.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 607
Rev 01.24
Figure 20-27. Example Mass Erase Command Flow
Write: Flash Block Address
Write: FCMD register
Mass Erase Command 0x41
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
608 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
20.4.1.4 Illegal Flash Operations
20.4.1.4.1 Access Error
The ACCERR flag in the FSTAT register will be set during the command write sequence if any of the
following illegal Flash operations are performed causing the command write sequence to immediately
abort:
1. Writing to the Flash address space before initializing the FCLKDIV register
2. Writing a misaligned word or a byte to the valid Flash address space
3. Writing to the Flash address space while CBEIF is not set
4. Writing a second word to the Flash address space before executing a program or erase command
on the previously written word
5. Writing to any Flash register other than FCMD after writing a word to the Flash address space
6. Writing a second command to the FCMD register before executing the previously written
command
7. Writing an invalid command to the FCMD register
8. Writing to any Flash register other than FSTAT (to clear CBEIF) after writing to the FCMD register
9. The part enters stop mode and a program or erase command is in progress. The command is aborted
and any pending command is killed
10. When security is enabled, a command other than mass erase originating from a non-secure memory
or from the background debug mode is written to the FCMD register
11. A 0 is written to the CBEIF bit in the FSTAT register to abort a command write sequence.
The ACCERR flag will not be set if any Flash register is read during the command write sequence. If the
Flash array is read during execution of an algorithm (CCIF=0), the Flash module will return invalid data
and the ACCERR flag will not be set. If an ACCERR flag is set in the FSTAT register, the Flash command
controller is locked. It is not possible to launch another command until the ACCERR flag is cleared.
20.4.1.4.2 Protection Violation
The PVIOL flag in the FSTAT register will be set during the command write sequence after the word write
to the Flash address space if any of the following illegal Flash operations are performed, causing the
command write sequence to immediately abort:
1. Writing a Flash address to program in a protected area of the Flash array (see Section 20.3.2.5).
2. Writing a Flash address to erase in a protected area of the Flash array.
3. Writing the mass erase command to the FCMD register while any protection is enabled.
If the PVIOL flag is set, the Flash command controller is locked. It is not possible to launch another
command until the PVIOL flag is cleared.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 609
Rev 01.24
20.4.2 Operating Modes
20.4.2.1 Wait Mode
If the MCU enters wait mode while a Flash command is active (CCIF = 0), that command and any buffered
command will be completed.
The Flash module can recover the MCU from wait mode if the interrupts are enabled (see Section 20.4.5).
20.4.2.2 Stop Mode
If the MCU enters stop mode while a Flash command is active (CCIF = 0), that command will be aborted
and the data being programmed or erased is lost. The high voltage circuitry to the Flash array will be
switched off when entering stop mode. CCIF and ACCERR flags will be set. Upon exit from stop mode,
the CBEIF flag will be set and any buffered command will not be executed. The ACCERR flag must be
cleared before returning to normal operation.
NOTE
As active Flash commands are immediately aborted when the MCU enters
stop mode, it is strongly recommended that the user does not use the STOP
instruction during program and erase execution.
20.4.2.3 Background Debug Mode
In background debug mode (BDM), the FPROT register is writable. If the MCU is unsecured, then all
Flash commands listed in Table 20-17 can be executed. If the MCU is secured and is in special single chip
mode, the only possible command to execute is mass erase.
20.4.3 Flash Module Security
The Flash module provides the necessary security information to the MCU. After each reset, the Flash
module determines the security state of the MCU as defined in Section 20.3.2.2, “Flash Security Register
(FSEC)”.
The contents of the Flash security/options byte at address 0xFF0F in the Flash configuration field must be
changed directly by programming address 0xFF0F when the device is unsecured and the higher address
sector is unprotected. If the Flash security/options byte is left in the secure state, any reset will cause the
MCU to return to the secure operating mode.
20.4.3.1 Unsecuring the MCU using Backdoor Key Access
The MCU may only be unsecured by using the backdoor key access feature which requires knowledge of
the contents of the backdoor key (four 16-bit words programmed at addresses 0xFF00–0xFF07). If
KEYEN[1:0] = 1:0 and the KEYACC bit is set, a write to a backdoor key address in the Flash array triggers
a comparison between the written data and the backdoor key data stored in the Flash array. If all four words
of data are written to the correct addresses in the correct order and the data matches the backdoor key
stored in the Flash array, the MCU will be unsecured. The data must be written to the backdoor key
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
610 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
addresses sequentially staring with 0xFF00-0xFF01 and ending with 0xFF06–0xFF07. The values 0x0000
and 0xFFFF are not permitted as keys. When the KEYACC bit is set, reads of the Flash array will return
invalid data.
The user code stored in the Flash array must have a method of receiving the backdoor key from an external
stimulus. This external stimulus would typically be through one of the on-chip serial ports.
If KEYEN[1:0] = 1:0 in the FSEC register, the MCU can be unsecured by the backdoor key access
sequence described below:
1. Set the KEYACC bit in the FCNFG register
2. Write the correct four 16-bit words to Flash addresses 0xFF00–0xFF07 sequentially starting with
0xFF00
3. Clear the KEYACC bit in the FCNFG register
4. If all four 16-bit words match the backdoor key stored in Flash addresses 0xFF00–0xFF07, the
MCU is unsecured and bits SEC[1:0] in the FSEC register are forced to the unsecure state of 1:0
The backdoor key access sequence is monitored by the internal security state machine. An illegal operation
during the backdoor key access sequence will cause the security state machine to lock, leaving the MCU
in the secured state. A reset of the MCU will cause the security state machine to exit the lock state and
allow a new backdoor key access sequence to be attempted. The following illegal operations will lock the
security state machine:
1. If any of the four 16-bit words does not match the backdoor key programmed in the Flash array
2. If the four 16-bit words are written in the wrong sequence
3. If more than four 16-bit words are written
4. If any of the four 16-bit words written are 0x0000 or 0xFFFF
5. If the KEYACC bit does not remain set while the four 16-bit words are written
After the backdoor key access sequence has been correctly matched, the MCU will be unsecured. The
Flash security byte can be programmed to the unsecure state, if desired.
In the unsecure state, the user has full control of the contents of the four word backdoor key by
programming bytes 0xFF00–0xFF07 of the Flash configuration field.
The security as defined in the Flash security/options byte at address 0xFF0F is not changed by using the
backdoor key access sequence to unsecure. The backdoor key stored in addresses 0xFF00–0xFF07 is
unaffected by the backdoor key access sequence. After the next reset sequence, the security state of the
Flash module is determined by the Flash security/options byte at address 0xFF0F. The backdoor key access
sequence has no effect on the program and erase protection defined in the FPROT register.
It is not possible to unsecure the MCU in special single chip mode by executing the backdoor key access
sequence in background debug mode.
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 611
Rev 01.24
20.4.4 Flash Reset Sequence
On each reset, the Flash module executes a reset sequence to hold CPU activity while loading the following
registers from the Flash array memory according to Table 20-1:
• FPROT — Flash Protection Register (see Section 20.3.2.5)
• FSEC — Flash Security Register (see Section 20.3.2.2)
20.4.4.1 Reset While Flash Command Active
If a reset occurs while any Flash command is in progress, that command will be immediately aborted. The
state of the word being programmed or the sector/array being erased is not guaranteed.
20.4.5 Interrupts
The Flash module can generate an interrupt when all Flash commands have completed execution or the
Flash address, data, and command buffers are empty.
NOTE
Vector addresses and their relative interrupt priority are determined at the
MCU level.
20.4.5.1 Description of Interrupt Operation
Figure 20-28 shows the logic used for generating interrupts.
The Flash module uses the CBEIF and CCIF flags in combination with the enable bits CBIE and CCIE to
discriminate for the generation of interrupts.
Figure 20-28. Flash Interrupt Implementation
For a detailed description of these register bits, refer to Section 20.3.2.4, “Flash Configuration Register
(FCNFG)” and Section 20.3.2.6, “Flash Status Register (FSTAT)”.
Table 20-18. Flash Interrupt Sources
Interrupt Source Interrupt Flag Local Enable Global (CCR) Mask
Flash Address, Data, and Command
Buffers are empty
CBEIF
(FSTAT register)
CBEIE I Bit
All Flash commands have completed
execution
CCIF
(FSTAT register)
CCIE I Bit
CBEIF
CBEIE
CCIF
CCIE
FLASH INTERRUPT REQUEST
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
612 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 613
Rev 01.24
Chapter 21
128 Kbyte Flash Module (S12FTS128K1V1)
21.1 Introduction
The FTS128K1 module implements a 128 Kbyte Flash (nonvolatile) memory. The Flash memory contains
one array of 128 Kbytes organized as 1024 rows of 128 bytes with an erase sector size of eight rows (1024
bytes). The Flash array may be read as either bytes, aligned words, or misaligned words. Read access time
is one bus cycle for byte and aligned word, and two bus cycles for misaligned words.
The Flash array is ideal for program and data storage for single-supply applications allowing for field
reprogramming without requiring external voltage sources for program or erase. Program and erase
functions are controlled by a command driven interface. The Flash module supports both mass erase and
sector erase. An erased bit reads 1 and a programmed bit reads 0. The high voltage required to program
and erase is generated internally. It is not possible to read from a Flash array while it is being erased or
programmed.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
21.1.1 Glossary
Command Write Sequence — A three-step MCU instruction sequence to program, erase, or erase verify
the Flash array memory.
21.1.2 Features
•128 Kbytes of Flash memory comprised of one 128 Kbyte array divided into 128 sectors of 1024
bytes
• Automated program and erase algorithm
• Interrupts on Flash command completion and command buffer empty
• Fast sector erase and word program operation
• 2-stage command pipeline for faster multi-word program times
• Flexible protection scheme to prevent accidental program or erase
• Single power supply for Flash program and erase operations
• Security feature to prevent unauthorized access to the Flash array memory
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
614 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
21.1.3 Modes of Operation
See Section 21.4.2, “Operating Modes” for a description of the Flash module operating modes. For
program and erase operations, refer to Section 21.4.1, “Flash Command Operations”.
21.1.4 Block Diagram
Figure 21-1 shows a block diagram of the FTS128K1 module.
Figure 21-1. FTS128K1 Block Diagram
21.2 External Signal Description
The FTS128K1 module contains no signals that connect off-chip.
FTS128K1
Oscillator
Clock
Command
Complete
Interrupt
Command
Buffer Empty
Interrupt
Flash Array
64K * 16 Bits
sector 0
sector 1
sector 127
Clock
Divider FCLK
Protection
Security
Command Pipeline
cmd2
addr2
data2
cmd1
addr1
data1
Registers
Flash
Interface
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 615
Rev 01.24
21.3 Memory Map and Registers
This section describes the FTS128K1 memory map and registers.
21.3.1 Module Memory Map
The FTS128K1 memory map is shown in Figure 21-2. The HCS12 architecture places the Flash array
addresses between 0x4000 and 0xFFFF, which corresponds to three 16 Kbyte pages. The content of the
HCS12 Core PPAGE register is used to map the logical middle page ranging from address 0x8000 to
0xBFFF to any physical 16K byte page in the Flash array memory.1 The FPROT register (see Section
21.3.2.5) can be set to globally protect the entire Flash array. Three separate areas, one starting from the
Flash array starting address (called lower) towards higher addresses, one growing downward from the
Flash array end address (called higher), and the remaining addresses, can be activated for protection.The
Flash array addresses covered by these protectable regions are shown in Figure 21-2. The higher address
area is mainly targeted to hold the boot loader code since it covers the vector space. The lower address area
can be used for EEPROM emulation in an MCU without an EEPROM module since it can be left
unprotected while the remaining addresses are protected from program or erase. Default protection
settings as well as security information that allows the MCU to restrict access to the Flash module are
stored in the Flash configuration field described in Table 21-1.
1. By placing 0x3E/0x3F in the HCS12 Core PPAGE register, the bottom/top fixed 16 Kbyte pagescan be seen twice in the MCU
memory map.
Table 21-1. Flash Configuration Field
Flash Address Size
(bytes) Description
0xFF00–0xFF07 8 Backdoor Key to unlock security
0xFF08–0xFF0C 5 Reserved
0xFF0D 1 Flash Protection byte
Refer to Section 21.3.2.5, “Flash Protection Register (FPROT)”
0xFF0E 1 Reserved
0xFF0F 1 Flash Security/Options byte
Refer to Section 21.3.2.2, “Flash Security Register (FSEC)”
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
616 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 21-2. Flash Memory Map
Flash Registers
MODULE BASE + 0x0000
0xFF00–0xFF0F (Flash Configuration Field)
MODULE BASE + 0x000F
0x8000
Flash Protected Low Sectors
1, 2, 4, 8 Kbytes
FLASH_START = 0x4000
0x5000
0x4400
0x6000
16K PAGED
MEMORY
0x38 0x39 0x3A 0x3B
0x3E
0x3C 0x3D 003E 0x3F
Note: 0x38–0x3F correspond to the PPAGE register content
FLASH_END = 0xFFFF
0xF800
0xF000
0xC000
0xE000 Flash Protected High Sectors
2, 4, 8, 16 Kbytes
0x3F
0x4800
Flash Array
16 bytes
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 617
Rev 01.24
Table 21-2. Flash Array Memory Map Summary
MCU Address
Range PPAGE Protectable
Low Range
Protectable
High Range
Array Relative
Address(1)
1. Inside Flash block.
0x0000–0x3FFF(2)
2. If allowed by MCU.
Unpaged
(0x3D)
N.A. N.A. 0x14000–0x17FFF
0x4000–0x7FFF Unpaged
(0x3E)
0x4000–0x43FF N.A. 0x18000–0x1BFFF
0x4000–0x47FF
0x4000–0x4FFF
0x4000–0x5FFF
0x8000–0xBFFF 0x38 N.A. N.A. 0x00000–0x03FFF
0x39 N.A. N.A. 0x04000–0x07FFF
0x3A N.A. N.A. 0x08000–0x0BFFF
0x3B N.A. N.A. 0x0C000–0x0FFFF
0x3C N.A. N.A. 0x10000–0x13FFF
0x3D N.A. N.A. 0x14000–0x17FFF
0x3E 0x8000–0x83FF N.A. 0x18000–0x1BFFF
0x8000–0x87FF
0x8000–0x8FFF
0x8000–0x9FFF
0x3F N.A. 0xB800–0xBFFF 0x1C000–0x1FFFF
0xB000–0xBFFF
0xA000–0xBFFF
0x8000–0xBFFF
0xC000–0xFFFF Unpaged
(0x3F)
N.A. 0xF800–0xFFFF 0x1C000–0x1FFFF
0xF000–0xFFFF
0xE000–0xFFFF
0xC000–0xFFFF
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
618 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
21.3.2 Register Descriptions
The Flash module contains a set of 16 control and status registers located between module base + 0x0000
and 0x000F. A summary of the Flash module registers is given in Figure 21-3. Detailed descriptions of
each register bit are provided.
Register
Name Bit 7 6 5 4 3 2 1 Bit 0
0x0000
FCLKDIV
R FDIVLD PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
0x0001
FSEC
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
0x0002
RESERVED1
(1)
1. Intended for factory test purposes only.
R00000000
W
0x0003
FCNFG
RCBEIE CCIE KEYACC 00000
W
0x0004
FPROT
RFPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
0x0005
FSTAT
RCBEIF CCIF PVIOL ACCERR 0 BLANK FAIL DONE
W
0x0006
FCMD
R0 CMDB6 CMDB5 00
CMDB2 0CMDB0
W
0x0007
RESERVED21
R00000000
W
0x0008
FADDRHI1
RFABHI
W
0x0009
FADDRLO1
RFABLO
W
0x000A
FDATAHI1
RFDHI
W
0x000B
FDATALO1
RFDLO
W
0x000C
RESERVED31
R00000000
W
0x000D
RESERVED41
R00000000
W
0x000E
RESERVED51
R00000000
W
0x000F
RESERVED61
R00000000
W
= Unimplemented or Reserved
Figure 21-3. Flash Register Summary
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 619
Rev 01.24
21.3.2.1 Flash Clock Divider Register (FCLKDIV)
The FCLKDIV register is used to control timed events in program and erase algorithms.
All bits in the FCLKDIV register are readable, bits 6–0 are write once and bit 7 is not writable.
21.3.2.2 Flash Security Register (FSEC)
The FSEC register holds all bits associated with the security of the MCU and Flash module.
All bits in the FSEC register are readable but not writable.
The FSEC register is loaded from the Flash configuration field at 0xFF0F during the reset sequence,
indicated by F in Figure 21-5.
Module Base + 0x0000
76543210
R FDIVLD
PRDIV8 FDIV5 FDIV4 FDIV3 FDIV2 FDIV1 FDIV0
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-4. Flash Clock Divider Register (FCLKDIV)
Table 21-3. FCLKDIV Field Descriptions
Field Description
7
FDIVLD
Clock Divider Loaded
0 FCLKDIV register has not been written
1 FCLKDIV register has been written to since the last reset
6
PRDIV8
Enable Prescalar by 8
0 The oscillator clock is directly fed into the Flash clock divider
1 The oscillator clock is divided by 8 before feeding into the Flash clock divider
5–0
FDIV[5:0]
Clock Divider Bits — The combination of PRDIV8 and FDIV[5:0] must divide the oscillator clock down to a
frequency of 150 kHz – 200 kHz. The maximum divide ratio is 512. Refer to Section 21.4.1.1, “Writing the
FCLKDIV Register” for more information.
Module Base + 0x0001
76543210
R KEYEN1 KEYEN0 NV5 NV4 NV3 NV2 SEC1 SEC0
W
Reset F F FFFFFF
= Unimplemented or Reserved
Figure 21-5. Flash Security Register (FSEC)
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
620 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
The security function in the Flash module is described in Section 21.4.3, “Flash Module Security”.
21.3.2.3 RESERVED1
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
Table 21-4. FSEC Field Descriptions
Field Description
7–6
KEYEN[1:0]
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of the backdoor key access
to the Flash module as shown in Table 21-5.
5–2
NV[5:2]
Nonvolatile Flag Bits — The NV[5:2] bits are available to the user as nonvolatile flags.
1–0
SEC[1:0]
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in Table 21-6. If the
Flash module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
Table 21-5. Flash KEYEN States
KEYEN[1:0] Status of Backdoor Key Access
00 DISABLED
01(1)
1. Preferred KEYEN state to disable Backdoor Key Access.
DISABLED
10 ENABLED
11 DISABLED
Table 21-6. Flash Security States
SEC[1:0] Status of Security
00 Secured
01(1)
1. Preferred SEC state to set MCU to secured state.
Secured
10 Unsecured
11 Secured
Module Base + 0x0002
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-6. RESERVED1
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 621
Rev 01.24
21.3.2.4 Flash Configuration Register (FCNFG)
The FCNFG register enables the Flash interrupts and gates the security backdoor key writes.
CBEIE, CCIE, and KEYACC are readable and writable while remaining bits read 0 and are not writable.
KEYACC is only writable if the KEYEN bit in the FSEC register is set to the enabled state (see Section
21.3.2.2).
21.3.2.5 Flash Protection Register (FPROT)
The FPROT register defines which Flash sectors are protected against program or erase.
The FPROT register is readable in normal and special modes. FPOPEN can only be written from a 1 to a 0.
FPLS[1:0] can be written anytime until FPLDIS is cleared. FPHS[1:0] can be written anytime until
Module Base + 0x0003
76543210
R
CBEIE CCIE KEYACC
00000
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-7. Flash Configuration Register (FCNFG)
Table 21-7. FCNFG Field Descriptions
Field Description
7
CBEIE
Command Buffer Empty Interrupt Enable — The CBEIE bit enables the interrupts in case of an empty
command buffer in the Flash module.
0 Command Buffer Empty interrupts disabled
1 An interrupt will be requested whenever the CBEIF flag is set (see Section 21.3.2.6)
6
CCIE
Command Complete Interrupt Enable — The CCIE bit enables the interrupts in case of all commands being
completed in the Flash module.
0 Command Complete interrupts disabled
1 An interrupt will be requested whenever the CCIF flag is set (see Section 21.3.2.6)
5
KEYACC
Enable Security Key Writing.
0 Flash writes are interpreted as the start of a command write sequence
1 Writes to the Flash array are interpreted as a backdoor key while reads of the Flash array return invalid data
Module Base + 0x0004
76543210
R
FPOPEN NV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0
W
Reset F F FFFFFF
Figure 21-8. Flash Protection Register (FPROT)
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
622 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
FPHDIS is cleared. The FPROT register is loaded from Flash address 0xFF0D during the reset sequence,
indicated by F in Figure 21-8.
To change the Flash protection that will be loaded on reset, the upper sector of the Flash array must be
unprotected, then the Flash protection byte located at Flash address 0xFF0D must be written to.
A protected Flash sector is disabled by FPHDIS and FPLDIS while the size of the protected sector is
defined by FPHS[1:0] and FPLS[1:0] in the FPROT register.
Trying to alter any of the protected areas will result in a protect violation error and the PVIOL flag will be
set in the FSTAT register (see Section 21.3.2.6). A mass erase of the whole Flash array is only possible
when protection is fully disabled by setting the FPOPEN, FPLDIS, and FPHDIS bits. An attempt to mass
erase a Flash array while protection is enabled will set the PVIOL flag in the FSTAT register.
Table 21-8. FPROT Field Descriptions
Field Description
7
FPOPEN
Protection Function for Program or Erase — It is possible using the FPOPEN bit to either select address
ranges to be protected using FPHDIS, FPLDIS, FPHS[1:0] and FPLS[1:0] or to select the same ranges to be
unprotected. When FPOPEN is set, FPxDIS enables the ranges to be protected, whereby clearing FPxDIS
enables protection for the range specified by the corresponding FPxS[1:0] bits. When FPOPEN is cleared,
FPxDIS defines unprotected ranges as specified by the corresponding FPxS[1:0] bits. In this case, setting
FPxDIS enables protection. Thus the effective polarity of the FPxDIS bits is swapped by the FPOPEN bit as
shown in Table 21-9. This function allows the main part of the Flash array to be protected while a small range
can remain unprotected for EEPROM emulation.
0 The FPHDIS and FPLDIS bits define Flash address ranges to be unprotected
1 The FPHDIS and FPLDIS bits define Flash address ranges to be protected
6
NV6
Nonvolatile Flag Bit — The NV6 bit should remain in the erased state for future enhancements.
5
FPHDIS
Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a
protected/unprotected area in the higher space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
4–3
FPHS[1:0]
Flash Protection Higher Address Size — The FPHS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 21-10. The FPHS[1:0] bits can only be written to while the FPHDIS bit is set.
2
FPLDIS
Flash Protection Lower Address Range Disable — The FPLDIS bit determines whether there is a
protected/unprotected sector in the lower space of the Flash address map.
0 Protection/unprotection enabled
1 Protection/unprotection disabled
1–0
FPLS[1:0]
Flash Protection Lower Address Size — The FPLS[1:0] bits determine the size of the protected/unprotected
sector as shown in Table 21-11. The FPLS[1:0] bits can only be written to while the FPLDIS bit is set.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 623
Rev 01.24
Figure 21-9 illustrates all possible protection scenarios. Although the protection scheme is loaded from the
Flash array after reset, it is allowed to change in normal modes. This protection scheme can be used by
applications requiring re-programming in single chip mode while providing as much protection as possible
if no re-programming is required.
Table 21-9. Flash Protection Function
FPOPEN FPHDIS FPHS[1] FPHS[0] FPLDIS FPLS[1] FPLS[0] Function(1)
1. For range sizes refer to Table 21-10 and Table 21-11 or .
1 1 x x 1 x x No protection
1 1 x x 0 x x Protect low range
1 0 x x 1 x x Protect high range
1 0 x x 0 x x Protect high and low ranges
0 1 x x 1 x x Full Flash array protected
0 0 x x 1 x x Unprotected high range
0 1 x x 0 x x Unprotected low range
0 0 x x 0 x x Unprotected high and low ranges
Table 21-10. Flash Protection Higher Address Range
FPHS[1:0] Address Range Range Size
00 0xF800–0xFFFF 2 Kbytes
01 0xF000–0xFFFF 4 Kbytes
10 0xE000–0xFFFF 8 Kbytes
11 0xC000–0xFFFF 16 Kbytes
Table 21-11. Flash Protection Lower Address Range
FPLS[1:0] Address Range Range Size
00 0x4000–0x43FF 1 Kbyte
01 0x4000–0x47FF 2 Kbytes
10 0x4000–0x4FFF 4 Kbytes
11 0x4000–0x5FFF 8 Kbytes
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
624 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 21-9. Flash Protection Scenarios
21.3.2.5.1 Flash Protection Restrictions
The general guideline is that protection can only be added, not removed. All valid transitions between
Flash protection scenarios are specified in Table 21-12. Any attempt to write an invalid scenario to the
FPROT register will be ignored and the FPROT register will remain unchanged. The contents of the
FPROT register reflect the active protection scenario.
Table 21-12. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
0 XXXX
1XX
2XX
3X
4XX
5 XXXX
7654
FPOPEN = 1
3210
FPHS[1:0] FPLS[1:0]
FPOPEN = 0
FPHDIS = 1
FPLDIS = 1
FPHDIS = 1
FPLDIS = 0
FPHDIS = 0
FPLDIS = 1
FPHDIS = 0
FPLDIS = 0
Scenario
Scenario
Protected Flash
FPHS[1:0] FPLS[1:0]
0xFFFF
0xFFFF
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 625
Rev 01.24
21.3.2.6 Flash Status Register (FSTAT)
The FSTAT register defines the status of the Flash command controller and the results of command
execution.
In normal modes, bits CBEIF, PVIOL, and ACCERR are readable and writable, bits CCIF and BLANK
are readable and not writable, remaining bits, including FAIL and DONE, read 0 and are not writable. In
special modes, FAIL is readable and writable while DONE is readable but not writable. FAIL must be clear
in special modes when starting a command write sequence.
6XXXX
7 XXXXXXXX
1. Allowed transitions marked with X.
Module Base + 0x0005
76543210
R
CBEIF
CCIF
PVIOL ACCERR
0 BLANK
FAIL
DONE
W
Reset 11000001
= Unimplemented or Reserved
Figure 21-10. Flash Status Register (FSTAT)
Table 21-13. FSTAT Field Descriptions
Field Description
7
CBEIF
Command Buffer Empty Interrupt Flag — The CBEIF flag indicates that the address, data and command
buffers are empty so that a new command write sequence can be started. The CBEIF flag is cleared by writing
a 1 to CBEIF. Writing a 0 to the CBEIF flag has no effect on CBEIF. Writing a 0 to CBEIF after writing an aligned
word to the Flash address space but before CBEIF is cleared will abort a command write sequence and cause
the ACCERR flag in the FSTAT register to be set. Writing a 0 to CBEIF outside of a command write sequence
will not set the ACCERR flag. The CBEIF flag is used together with the CBEIE bit in the FCNFG register to
generate an interrupt request (see Figure 21-26).
0 Buffers are full
1 Buffers are ready to accept a new command
6
CCIF
Command Complete Interrupt Flag — The CCIF flag indicates that there are no more commands pending. The
CCIF flag is cleared when CBEIF is clear and sets automatically upon completion of all active and pending
commands. The CCIF flag does not set when an active commands completes and a pending command is
fetched from the command buffer. Writing to the CCIF flag has no effect. The CCIF flag is used together with the
CCIE bit in the FCNFG register to generate an interrupt request (see Figure 21-26).
0 Command in progress
1 All commands are completed
Table 21-12. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
626 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
21.3.2.7 Flash Command Register (FCMD)
The FCMD register defines the Flash commands.
Bits CMDB6, CMDB5, CMDB2, and CMDB0 are readable and writable during a command write
sequence while bits 7, 4, 3, and 1 read 0 and are not writable.
5
PVIOL
Protection Violation — The PVIOL flag indicates an attempt was made to program or erase an address in a
protected Flash array memory area. The PVIOL flag is cleared by writing a 1 to PVIOL. Writing a 0 to the PVIOL
flag has no effect on PVIOL. While PVIOL is set, it is not possible to launch another command.
0 No protection violation detected
1 Protection violation has occurred
4
ACCERR
Access Error — The ACCERR flag indicates an illegal access to the Flash array caused by either a violation of
the command write sequence, issuing an illegal command (illegal combination of the CMDBx bits in the FCMD
register) or the execution of a CPU STOP instruction while a command is executing (CCIF=0). The ACCERR flag
is cleared by writing a 1 to ACCERR. Writing a 0 to the ACCERR flag has no effect on ACCERR. While ACCERR
is set, it is not possible to launch another command.
0 No access error detected
1 Access error has occurred
2
BLANK
Flash Array Has Been Verified as Erased — The BLANK flag indicates that an erase verify command has
checked the Flash array and found it to be erased. The BLANK flag is cleared by hardware when CBEIF is
cleared as part of a new valid command write sequence. Writing to the BLANK flag has no effect on BLANK.
0 If an erase verify command has been requested, and the CCIF flag is set, then a 0 in BLANK indicates the
array is not erased
1 Flash array verifies as erased
1
FAIL
Flag Indicating a Failed Flash Operation — In special modes, the FAIL flag will set if the erase verify operation
fails (Flash array verified as not erased). Writing a 0 to the FAIL flag has no effect on FAIL. The FAIL flag is cleared
by writing a 1 to FAIL. While FAIL is set, it is not possible to launch another command.
0 Flash operation completed without error
1 Flash operation failed
0
DONE
Flag Indicating a Failed Operation is not Active — In special modes, the DONE flag will clear if a program,
erase, or erase verify operation is active.
0 Flash operation is active
1 Flash operation is not active
Module Base + 0x0006
76543210
R0
CMDB6 CMDB5
00
CMDB2
0
CMDB0
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-11. Flash Command Register (FCMD)
Table 21-13. FSTAT Field Descriptions
Field Description
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 627
Rev 01.24
21.3.2.8 RESERVED2
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
21.3.2.9 Flash Address Register (FADDR)
FADDRHI and FADDRLO are the Flash address registers.
\
\
\
Table 21-14. FCMD Field Descriptions
Field Description
6, 5, 2, 0
CMDB[6:5]
CMDB[2]
CMDB[0]
Valid Flash commands are shown in Table 21-15. An attempt to execute any command other than those listed in
Table 21-15 will set the ACCERR bit in the FSTAT register (see Section 21.3.2.6).
Table 21-15. Valid Flash Command List
CMDB NVM Command
0x05 Erase verify
0x20 Word program
0x40 Sector erase
0x41 Mass erase
Module Base + 0x0007
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-12. RESERVED2
Module Base + 0x0008
76543210
R
FABHI
W
Reset 00000000
Figure 21-13. Flash Address High Register (FADDRHI)
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
628 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
In normal modes, all FABHI and FABLO bits read 0 and are not writable. In special modes, the FABHI
and FABLO bits are readable and writable. For sector erase, the MCU address bits [9:0] are ignored.For
mass erase, any address within the Flash array is valid to start the command.
21.3.2.10 Flash Data Register (FDATA)
FDATAHI and FDATALO are the Flash data registers.
In normal modes, all FDATAHI and FDATALO bits read 0 and are not writable. In special modes, all
FDATAHI and FDATALO bits are readable and writable when writing to an address within the Flash
address range.
21.3.2.11 RESERVED3
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x0009
76543210
R
FABLO
W
Reset 00000000
Figure 21-14. Flash Address Low Register (FADDRLO)
Module Base + 0x000A
76543210
R
FDHI
W
Reset 00000000
Figure 21-15. Flash Data High Register (FDATAHI)
Module Base + 0x000B
76543210
R
FDLO
W
Reset 00000000
Figure 21-16. Flash Data Low Register (FDATALO)
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 629
Rev 01.24
All bits read 0 and are not writable.
21.3.2.12 RESERVED4
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
21.3.2.13 RESERVED5
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
21.3.2.14 RESERVED6
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x000C
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-17. RESERVED3
Module Base + 0x000D
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-18. RESERVED4
Module Base + 0x000E
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-19. RESERVED5
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
630 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
All bits read 0 and are not writable.
21.4 Functional Description
21.4.1 Flash Command Operations
Write operations are used for the program, erase, and erase verify algorithms described in this section. The
program and erase algorithms are controlled by a state machine whose timebase FCLK is derived from the
oscillator clock via a programmable divider. The FCMD register as well as the associated FADDR and
FDATA registers operate as a buffer and a register (2-stage FIFO) so that a new command along with the
necessary data and address can be stored to the buffer while the previous command is still in progress. This
pipelined operation allows a time optimization when programming more than one word on a specific row,
as the high voltage generation can be kept active in between two programming commands. The pipelined
operation also allows a simplification of command launching. Buffer empty as well as command
completion are signalled by flags in the FSTAT register with corresponding interrupts generated, if
enabled.
The next sections describe:
• How to write the FCLKDIV register
• Command write sequence used to program, erase or erase verify the Flash array
• Valid Flash commands
• Errors resulting from illegal Flash operations
21.4.1.1 Writing the FCLKDIV Register
Prior to issuing any Flash command after a reset, it is first necessary to write the FCLKDIV register to
divide the oscillator clock down to within the 150-kHz to 200-kHz range. Since the program and erase
timings are also a function of the bus clock, the FCLKDIV determination must take this information into
account.
If we define:
• FCLK as the clock of the Flash timing control block
• Tbus as the period of the bus clock
• INT(x) as taking the integer part of x (e.g., INT(4.323) = 4),
Module Base + 0x000F
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 21-20. RESERVED6
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 631
Rev 01.24
then FCLKDIV register bits PRDIV8 and FDIV[5:0] are to be set as described in Figure 21-21.
For example, if the oscillator clock frequency is 950 kHz and the bus clock is 10 MHz, FCLKDIV bits
FDIV[5:0] should be set to 4 (000100) and bit PRDIV8 set to 0. The resulting FCLK is then 190 kHz. As
a result, the Flash algorithm timings are increased over optimum target by:
Command execution time will increase proportionally with the period of FCLK.
CAUTION
Because of the impact of clock synchronization on the accuracy of the
functional timings, programming or erasing the Flash array cannot be
performed if the bus clock runs at less than 1 MHz. Programming or erasing
the Flash array with an input clock < 150 kHz should be avoided. Setting
FCLKDIV to a value such that FCLK < 150 kHz can destroy the Flash array
due to overstress. Setting FCLKDIV to a value such that (1/FCLK + Tbus)
< 5µs can result in incomplete programming or erasure of the Flash array
cells.
If the FCLKDIV register is written, the bit FDIVLD is set automatically. If the FDIVLD bit is 0, the
FCLKDIV register has not been written since the last reset. If the FCLKDIV register has not been written
to, the Flash command loaded during a command write sequence will not execute and the ACCERR flag
in the FSTAT register will set.
200 190–()200⁄100×5%=
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
632 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 21-21. PRDIV8 and FDIV Bits Determination Procedure
PRDIV8=1
yes
no
PRDIV8=0 (reset)
12.8MHz?
FCLK=(PRDCLK)/(1+FDIV[5:0])
PRDCLK=oscillator_clock
PRDCLK=oscillator_clock/8
PRDCLK[MHz]*(5+Tbus[µs]) no
FDIV[5:0]=PRDCLK[MHz]*(5+Tbus[µs])-1
yes
START
Tbus < 1µs?
an integer?
FDIV[5:0]=INT(PRDCLK[MHz]*(5+Tbus[µs]))
1/FCLK[MHz] + Tbus[µs] > 5
AND
FCLK > 0.15MHz
?
END
yes
no
FDIV[5:0] > 4?
ALL COMMANDS IMPOSSIBLE
yes
no
ALL COMMANDS IMPOSSIBLE
no
TRY TO DECREASE Tbus
yes
oscillator_clock
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 633
Rev 01.24
21.4.1.2 Command Write Sequence
The Flash command controller is used to supervise the command write sequence to execute program,
erase, and erase verify algorithms.
Before starting a command write sequence, the ACCERR and PVIOL flags in the FSTAT register must be
clear and the CBEIF flag should be tested to determine the state of the address, data, and command buffers.
If the CBEIF flag is set, indicating the buffers are empty, a new command write sequence can be started.
If the CBEIF flag is clear, indicating the buffers are not available, a new command write sequence will
overwrite the contents of the address, data, and command buffers.
A command write sequence consists of three steps which must be strictly adhered to with writes to the
Flash module not permitted between the steps. However, Flash register and array reads are allowed during
a command write sequence. The basic command write sequence is as follows:
1. Write to a valid address in the Flash array memory.
2. Write a valid command to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the command.
The address written in step 1 will be stored in the FADDR registers and the data will be stored in the
FDATA registers. When the CBEIF flag is cleared in step 3, the CCIF flag is cleared by the Flash command
controller indicating that the command was successfully launched. For all command write sequences, the
CBEIF flag will set after the CCIF flag is cleared indicating that the address, data, and command buffers
are ready for a new command write sequence to begin. A buffered command will wait for the active
operation to be completed before being launched. Once a command is launched, the completion of the
command operation is indicated by the setting of the CCIF flag in the FSTAT register. The CCIF flag will
set upon completion of all active and buffered commands.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
634 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
21.4.1.3 Valid Flash Commands
Table 21-16 summarizes the valid Flash commands along with the effects of the commands on the Flash
array.
CAUTION
A Flash word must be in the erased state before being programmed.
Cumulative programming of bits within a Flash word is not allowed.
Table 21-16. Valid Flash Commands
FCMD Meaning Function on Flash Array
0x05 Erase
Verify
Verify all bytes in the Flash array are erased.
If the Flash array is erased, the BLANK bit will set in the FSTAT register upon command completion.
0x20 Program Program a word (2 bytes) in the Flash array.
0x40 Sector
Erase
Erase all 1024 bytes in a sector of the Flash array.
0x41 Mass
Erase
Erase all bytes in the Flash array.
A mass erase of the full Flash array is only possible when FPLDIS, FPHDIS, and FPOPEN bits in
the FPROT register are set prior to launching the command.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 635
Rev 01.24
21.4.1.3.1 Erase Verify Command
The erase verify operation will verify that a Flash array is erased.
An example flow to execute the erase verify operation is shown in Figure 21-22. The erase verify command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the erase verify command.
The address and data written will be ignored.
2. Write the erase verify command, 0x05, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the erase verify
command.
After launching the erase verify command, the CCIF flag in the FSTAT register will set after the operation
has completed unless a new command write sequence has been buffered. Upon completion of the erase
verify operation, the BLANK flag in the FSTAT register will be set if all addresses in the Flash array are
verified to be erased. If any address in the Flash array is not erased, the erase verify operation will terminate
and the BLANK flag in the FSTAT register will remain clear.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
636 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 21-22. Example Erase Verify Command Flow
Write: Flash Array Address
Write: FCMD register
Erase Verify Command 0x05
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and Dummy Data
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CCIF
Set?
ACCERR/
PVIOL
Set?
no
Erase Verify
Status
yes
EXIT
Flash Array
Not Erased
EXIT
Flash Array
Erased
BLANK
Set?
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 637
Rev 01.24
21.4.1.3.2 Program Command
The program operation will program a previously erased word in the Flash array using an embedded
algorithm.
An example flow to execute the program operation is shown in Figure 21-23. The program command write
sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the program command. The
data written will be programmed to the Flash array address written.
2. Write the program command, 0x20, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the program
command.
If a word to be programmed is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the program command will not launch. Once the program command has successfully launched,
the CCIF flag in the FSTAT register will set after the program operation has completed unless a new
command write sequence has been buffered. By executing a new program command write sequence on
sequential words after the CBEIF flag in the FSTAT register has been set, up to 55% faster programming
time per word can be effectively achieved than by waiting for the CCIF flag to set after each program
operation.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
638 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 21-23. Example Program Command Flow
Write: Flash Address
Write: FCMD register
Program Command 0x20
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
no
and program Data
Bit Polling for
Buffer Empty
Check
Read: FSTAT register
yes
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
CBEIF
Set?
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
yes
Sequential
Programming
Decision
Next
Word?
no
Bit Polling for
Command Completion
Check
Read: FSTAT register
yes
CCIF
Set?
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 639
Rev 01.24
21.4.1.3.3 Sector Erase Command
The sector erase operation will erase all addresses in a 1024 byte sector of the Flash array using an
embedded algorithm.
An example flow to execute the sector erase operation is shown in Figure 21-24. The sector erase
command write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the sector erase command.
The Flash address written determines the sector to be erased while MCU address bits [9:0] and the
data written are ignored.
2. Write the sector erase command, 0x40, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the sector erase
command.
If a Flash sector to be erased is in a protected area of the Flash array, the PVIOL flag in the FSTAT register
will set and the sector erase command will not launch. Once the sector erase command has successfully
launched, the CCIF flag in the FSTAT register will set after the sector erase operation has completed unless
a new command write sequence has been buffered.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
640 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 21-24. Example Sector Erase Command Flow
Write: Flash Sector Address
Write: FCMD register
Sector Erase Command 0x40
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 641
Rev 01.24
21.4.1.3.4 Mass Erase Command
The mass erase operation will erase all addresses in a Flash array using an embedded algorithm.
An example flow to execute the mass erase operation is shown in Figure 21-25. The mass erase command
write sequence is as follows:
1. Write to a Flash array address to start the command write sequence for the mass erase command.
The address and data written will be ignored.
2. Write the mass erase command, 0x41, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the mass erase
command.
If a Flash array to be erased contains any protected area, the PVIOL flag in the FSTAT register will set and
the mass erase command will not launch. Once the mass erase command has successfully launched, the
CCIF flag in the FSTAT register will set after the mass erase operation has completed unless a new
command write sequence has been buffered.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
642 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure 21-25. Example Mass Erase Command Flow
Write: Flash Block Address
Write: FCMD register
Mass Erase Command 0x41
Write: FSTAT register
Clear CBEIF 0x80
1.
2.
3.
Clear ACCERR/PVIOL 0x30
Write: FSTAT register
yes
no
Access Error and
Protection Violation
and Dummy Data
Read: FSTAT register
Read: FSTAT register
no
START
yes
Check
CBEIF
Set?
Address, Data,
Command
Buffer Empty Check
ACCERR/
PVIOL
Set?
EXIT
Write: FCLKDIV register
Read: FCLKDIV register
yes
no
Clock Register
Written
Check
FDIVLD
Set?
NOTE: FCLKDIV needs to
be set once after each reset.
no
Bit Polling for
Command Completion
Check
yes
CCIF
Set?
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 643
Rev 01.24
21.4.1.4 Illegal Flash Operations
21.4.1.4.1 Access Error
The ACCERR flag in the FSTAT register will be set during the command write sequence if any of the
following illegal Flash operations are performed causing the command write sequence to immediately
abort:
1. Writing to the Flash address space before initializing the FCLKDIV register
2. Writing a misaligned word or a byte to the valid Flash address space
3. Writing to the Flash address space while CBEIF is not set
4. Writing a second word to the Flash address space before executing a program or erase command
on the previously written word
5. Writing to any Flash register other than FCMD after writing a word to the Flash address space
6. Writing a second command to the FCMD register before executing the previously written
command
7. Writing an invalid command to the FCMD register
8. Writing to any Flash register other than FSTAT (to clear CBEIF) after writing to the FCMD register
9. The part enters stop mode and a program or erase command is in progress. The command is aborted
and any pending command is killed
10. When security is enabled, a command other than mass erase originating from a non-secure memory
or from the background debug mode is written to the FCMD register
11. A 0 is written to the CBEIF bit in the FSTAT register to abort a command write sequence.
The ACCERR flag will not be set if any Flash register is read during the command write sequence. If the
Flash array is read during execution of an algorithm (CCIF=0), the Flash module will return invalid data
and the ACCERR flag will not be set. If an ACCERR flag is set in the FSTAT register, the Flash command
controller is locked. It is not possible to launch another command until the ACCERR flag is cleared.
21.4.1.4.2 Protection Violation
The PVIOL flag in the FSTAT register will be set during the command write sequence after the word write
to the Flash address space if any of the following illegal Flash operations are performed, causing the
command write sequence to immediately abort:
1. Writing a Flash address to program in a protected area of the Flash array (see Section 21.3.2.5).
2. Writing a Flash address to erase in a protected area of the Flash array.
3. Writing the mass erase command to the FCMD register while any protection is enabled.
If the PVIOL flag is set, the Flash command controller is locked. It is not possible to launch another
command until the PVIOL flag is cleared.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
644 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
21.4.2 Operating Modes
21.4.2.1 Wait Mode
If the MCU enters wait mode while a Flash command is active (CCIF = 0), that command and any buffered
command will be completed.
The Flash module can recover the MCU from wait mode if the interrupts are enabled (see Section 21.4.5).
21.4.2.2 Stop Mode
If the MCU enters stop mode while a Flash command is active (CCIF = 0), that command will be aborted
and the data being programmed or erased is lost. The high voltage circuitry to the Flash array will be
switched off when entering stop mode. CCIF and ACCERR flags will be set. Upon exit from stop mode,
the CBEIF flag will be set and any buffered command will not be executed. The ACCERR flag must be
cleared before returning to normal operation.
NOTE
As active Flash commands are immediately aborted when the MCU enters
stop mode, it is strongly recommended that the user does not use the STOP
instruction during program and erase execution.
21.4.2.3 Background Debug Mode
In background debug mode (BDM), the FPROT register is writable. If the MCU is unsecured, then all
Flash commands listed in Table 21-16 can be executed. If the MCU is secured and is in special single chip
mode, the only possible command to execute is mass erase.
21.4.3 Flash Module Security
The Flash module provides the necessary security information to the MCU. After each reset, the Flash
module determines the security state of the MCU as defined in Section 21.3.2.2, “Flash Security Register
(FSEC)”.
The contents of the Flash security/options byte at address 0xFF0F in the Flash configuration field must be
changed directly by programming address 0xFF0F when the device is unsecured and the higher address
sector is unprotected. If the Flash security/options byte is left in the secure state, any reset will cause the
MCU to return to the secure operating mode.
21.4.3.1 Unsecuring the MCU using Backdoor Key Access
The MCU may only be unsecured by using the backdoor key access feature which requires knowledge of
the contents of the backdoor key (four 16-bit words programmed at addresses 0xFF00–0xFF07). If
KEYEN[1:0] = 1:0 and the KEYACC bit is set, a write to a backdoor key address in the Flash array triggers
a comparison between the written data and the backdoor key data stored in the Flash array. If all four words
of data are written to the correct addresses in the correct order and the data matches the backdoor key
stored in the Flash array, the MCU will be unsecured. The data must be written to the backdoor key
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 645
Rev 01.24
addresses sequentially staring with 0xFF00-0xFF01 and ending with 0xFF06–0xFF07. The values 0x0000
and 0xFFFF are not permitted as keys. When the KEYACC bit is set, reads of the Flash array will return
invalid data.
The user code stored in the Flash array must have a method of receiving the backdoor key from an external
stimulus. This external stimulus would typically be through one of the on-chip serial ports.
If KEYEN[1:0] = 1:0 in the FSEC register, the MCU can be unsecured by the backdoor key access
sequence described below:
1. Set the KEYACC bit in the FCNFG register
2. Write the correct four 16-bit words to Flash addresses 0xFF00–0xFF07 sequentially starting with
0xFF00
3. Clear the KEYACC bit in the FCNFG register
4. If all four 16-bit words match the backdoor key stored in Flash addresses 0xFF00–0xFF07, the
MCU is unsecured and bits SEC[1:0] in the FSEC register are forced to the unsecure state of 1:0
The backdoor key access sequence is monitored by the internal security state machine. An illegal operation
during the backdoor key access sequence will cause the security state machine to lock, leaving the MCU
in the secured state. A reset of the MCU will cause the security state machine to exit the lock state and
allow a new backdoor key access sequence to be attempted. The following illegal operations will lock the
security state machine:
1. If any of the four 16-bit words does not match the backdoor key programmed in the Flash array
2. If the four 16-bit words are written in the wrong sequence
3. If more than four 16-bit words are written
4. If any of the four 16-bit words written are 0x0000 or 0xFFFF
5. If the KEYACC bit does not remain set while the four 16-bit words are written
After the backdoor key access sequence has been correctly matched, the MCU will be unsecured. The
Flash security byte can be programmed to the unsecure state, if desired.
In the unsecure state, the user has full control of the contents of the four word backdoor key by
programming bytes 0xFF00–0xFF07 of the Flash configuration field.
The security as defined in the Flash security/options byte at address 0xFF0F is not changed by using the
backdoor key access sequence to unsecure. The backdoor key stored in addresses 0xFF00–0xFF07 is
unaffected by the backdoor key access sequence. After the next reset sequence, the security state of the
Flash module is determined by the Flash security/options byte at address 0xFF0F. The backdoor key access
sequence has no effect on the program and erase protection defined in the FPROT register.
It is not possible to unsecure the MCU in special single chip mode by executing the backdoor key access
sequence in background debug mode.
Chapter 21 128 Kbyte Flash Module (S12FTS128K1V1)
646 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
21.4.4 Flash Reset Sequence
On each reset, the Flash module executes a reset sequence to hold CPU activity while loading the following
registers from the Flash array memory according to Table 21-1:
• FPROT — Flash Protection Register (see Section 21.3.2.5)
• FSEC — Flash Security Register (see Section 21.3.2.2)
21.4.4.1 Reset While Flash Command Active
If a reset occurs while any Flash command is in progress, that command will be immediately aborted. The
state of the word being programmed or the sector/array being erased is not guaranteed.
21.4.5 Interrupts
The Flash module can generate an interrupt when all Flash commands have completed execution or the
Flash address, data, and command buffers are empty.
NOTE
Vector addresses and their relative interrupt priority are determined at the
MCU level.
21.4.5.1 Description of Interrupt Operation
Figure 21-26 shows the logic used for generating interrupts.
The Flash module uses the CBEIF and CCIF flags in combination with the enable bits CBIE and CCIE to
discriminate for the generation of interrupts.
Figure 21-26. Flash Interrupt Implementation
For a detailed description of these register bits, refer to Section 21.3.2.4, “Flash Configuration Register
(FCNFG)” and Section 21.3.2.6, “Flash Status Register (FSTAT)”.
Table 21-17. Flash Interrupt Sources
Interrupt Source Interrupt Flag Local Enable Global (CCR) Mask
Flash Address, Data, and Command
Buffers are empty
CBEIF
(FSTAT register)
CBEIE I Bit
All Flash commands have completed
execution
CCIF
(FSTAT register)
CCIE I Bit
CBEIF
CBEIE
CCIF
CCIE
FLASH INTERRUPT REQUEST
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 647
Rev 01.24
Appendix A
Electrical Characteristics
A.1 General
NOTE
The electrical characteristics given in this section are preliminary and
should be used as a guide only. Values cannot be guaranteed by Freescale
and are subject to change without notice.
The parts are specified and tested over the 5V and 3.3V ranges. For the
intermediate range, generally the electrical specifications for the 3.3V range
apply, but the parts are not tested in production test in the intermediate
range.
This supplement contains the most accurate electrical information for the MC9S12C-Family /
MC9S12GC-Family microcontrollers available at the time of publication. The information should be
considered PRELIMINARY and is subject to change.
This introduction is intended to give an overview on several common topics like power supply, current
injection etc.
A.1.1 Parameter Classification
The electrical parameters shown in this supplement are guaranteed by various methods. To give the
customer a better understanding the following classification is used and the parameters are tagged
accordingly in the tables where appropriate.
NOTE
This classification will be added at a later release of the specification
P: Those parameters are guaranteed during production testing on each individual device.
C: Those parameters are achieved by the design characterization by measuring a statistically relevant
sample size across process variations. They are regularly verified by production monitors.
T: Those parameters are achieved by design characterization on a small sample size from typical
devices. All values shown in the typical column are within this category.
D: Those parameters are derived mainly from simulations.
A.1.2 Power Supply
The MC9S12C-Family / MC9S12GC-Family and MC9S12GC Family members utilize several pins to
supply power to the I/O ports, A/D converter, oscillator and PLL as well as the internal logic.
The VDDA, VSSA pair supplies the A/D converter.
The VDDX, VSSX pair supplies the I/O pins
The VDDR, VSSR pair supplies the internal voltage regulator.
Appendix A Electrical Characteristics
648 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
VDD1, VSS1, VDD2 and VSS2 are the supply pins for the digital logic.
VDDPLL, VSSPLL supply the oscillator and the PLL.
VSS1 and VSS2 are internally connected by metal.
VDD1 and VDD2 are internally connected by metal.
VDDA, VDDX, VDDR as well as VSSA, VSSX, VSSR are connected by anti-parallel diodes for ESD
protection.
NOTE
In the following context VDD5 is used for either VDDA,V
DDR, and VDDX;
VSS5 is used for either VSSA, VSSR, and VSSX unless otherwise noted.
IDD5 denotes the sum of the currents flowing into the VDDA, VDDX, and
VDDR pins.
VDD is used for VDD1,V
DD2, and VDDPLL,V
SS is used for VSS1,V
SS2, and
VSSPLL.
IDD is used for the sum of the currents flowing into VDD1 and VDD2.
A.1.3 Pins
There are four groups of functional pins.
A.1.3.1 5V I/O Pins
Those I/O pins have a nominal level of 5V. This class of pins is comprised of all port I/O pins, the analog
inputs, BKGD pin, and the RESET inputs.The internal structure of all those pins is identical; however
some of the functionality may be disabled. For example, pull-up and pull-down resistors may be disabled
permanently.
A.1.3.2 Analog Reference
This class is made up by the two VRH and VRL pins. In 48- and 52-pin package versions the VRL pad is
bonded to the VSSA pin.
A.1.3.3 Oscillator
The pins XFC, EXTAL, XTAL dedicated to the oscillator have a nominal 2.5V level. They are supplied by
VDDPLL.
A.1.3.4 TEST
This pin is used for production testing only.
A.1.4 Current Injection
Power supply must maintain regulation within operating VDD5 or VDD range during instantaneous and
operating maximum current conditions. If positive injection current (Vin >V
DD5) is greater than IDD5, the
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 649
Rev 01.24
injection current may flow out of VDD5 and could result in external power supply going out of regulation.
Insure external VDD5 load will shunt current greater than maximum injection current. This will be the
greatest risk when the MCU is not consuming power; e.g. if no system clock is present, or if clock rate is
very low which would reduce overall power consumption.
A.1.5 Absolute Maximum Ratings
Absolute maximum ratings are stress ratings only. A functional operation under or outside those maxima
is not guaranteed. Stress beyond those limits may affect the reliability or cause permanent damage of the
device.
This device contains circuitry protecting against damage due to high static voltage or electrical fields;
however, it is advised that normal precautions be taken to avoid application of any voltages higher than
maximum-rated voltages to this high-impedance circuit. Reliability of operation is enhanced if unused
inputs are tied to an appropriate logic voltage level (e.g., either VSS5 or VDD5).
Table A-1. Absolute Maximum Ratings
Num Rating Symbol Min Max Unit
1 I/O, Regulator and Analog Supply Voltage VDD5 –0.3 6.5 V
2 Digital Logic Supply Voltage(1)
1. The device contains an internal voltage regulator to generate the logic and PLL supply out of the I/O supply. The absolute
maximum ratings apply when the device is powered from an external source.
VDD –0.3 3.0 V
3 PLL Supply Voltage 1VDDPLL –0.3 3.0 V
4 Voltage difference VDDX to VDDR and VDDA ∆VDDX –0.3 0.3 V
5 Voltage difference VSSX to VSSR and VSSA ∆VSSX –0.3 0.3 V
6 Digital I/O Input Voltage VIN –0.3 6.5 V
7 Analog Reference VRH, VRL –0.3 6.5 V
8 XFC, EXTAL, XTAL inputs VILV –0.3 3.0 V
9 TEST input VTEST –0.3 10.0 V
10 Instantaneous Maximum Current
Single pin limit for all digital I/O pins (2)
2. All digital I/O pins are internally clamped to VSSX and VDDX, VSSR and VDDR or VSSA and VDDA.
ID–25 +25 mA
11 Instantaneous Maximum Current
Single pin limit for XFC, EXTAL, XTAL(3)
3. These pins are internally clamped to VSSPLL and VDDPLL
IDL –25 +25 mA
12 Instantaneous Maximum Current
Single pin limit for TEST(4)
4. This pin is clamped low to VSSX, but not clamped high. This pin must be tied low in applications.
IDT –0.25 0 mA
13 Operating Temperature Range (packaged) TA– 40 125 °C
14 Operating Temperature Range (junction) TJ– 40 140 °C
15 Storage Temperature Range Tstg – 65 155 °C
Appendix A Electrical Characteristics
650 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.1.6 ESD Protection and Latch-up Immunity
All ESD testing is in conformity with CDF-AEC-Q100 Stress test qualification for Automotive Grade
Integrated Circuits. During the device qualification ESD stresses were performed for the Human Body
Model (HBM), the Machine Model (MM) and the Charge Device Model.
A device will be defined as a failure if after exposure to ESD pulses the device no longer meets the device
specification. Complete DC parametric and functional testing is performed per the applicable device
specification at room temperature followed by hot temperature, unless specified otherwise in the device
specification.
Table A-2. ESD and Latch-up Test Conditions
Model Description Symbol Value Unit
Human Body Series Resistance R1 1500 Ohm
Storage Capacitance C 100 pF
Number of Pulse per pin
Positive
Negative
—
—
3
3
Machine Series Resistance R1 0 Ohm
Storage Capacitance C 200 pF
Number of Pulse per pin
Positive
Negative
—
—
3
3
Latch-up Minimum input voltage limit — –2.5 V
Maximum input voltage limit — 7.5 V
Table A-3. ESD and Latch-Up Protection Characteristics
Num C Rating Symbol Min Max Unit
1 C Human Body Model (HBM) VHBM 2000 — V
2 C Machine Model (MM) VMM 200 — V
3 C Charge Device Model (CDM) VCDM 500 — V
4C
Latch-up Current at 125°C
Positive
Negative
ILAT +100
–100
—
—
mA
5C
Latch-up Current at 27°C
Positive
Negative
ILAT +200
–200
—
—
mA
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 651
Rev 01.24
A.1.7 Operating Conditions
This chapter describes the operating conditions of the devices. Unless otherwise noted those conditions
apply to all the following data.
NOTE
Instead of specifying ambient temperature all parameters are specified for
the more meaningful silicon junction temperature. For power dissipation
calculations refer to Section A.1.8, “Power Dissipation and Thermal
Characteristics”
.Table A-4. Operating Conditions
Rating Symbol Min Typ Max Unit
I/O, Regulator and Analog Supply Voltage VDD5 2.97 5 5.5 V
Digital Logic Supply Voltage (1)
1. The device contains an internal voltage regulator to generate the logic and PLL supply out of the I/O supply. The operating
conditions apply when this regulator is disabled and the device is powered from an external source.
Using an external regulator, with the internal voltage regulator disabled, an external LVR must be provided.
VDD 2.35 2.5 2.75 V
PLL Supply Voltage 1VDDPLL 2.35 2.5 2.75 V
Voltage Difference VDDX to VDDA ∆VDDX –0.1 0 0.1 V
Voltage Difference VSSX to VSSR and VSSA ∆VSSX –0.1 0 0.1 V
Bus Frequency fbus(2)
2. Some blocks e.g. ATD (conversion) and NVMs (program/erase) require higher bus frequencies for proper operation.
0.25 — 25 MHz
Bus Frequency fbus(3)
3. Some blocks e.g. ATD (conversion) and NVMs (program/erase) require higher bus frequencies for proper operation.
0.25 — 16 MHz
Operating Junction Temperature Range TJ–40 — 140 °C
Appendix A Electrical Characteristics
652 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.1.8 Power Dissipation and Thermal Characteristics
Power dissipation and thermal characteristics are closely related. The user must assure that the maximum
operating junction temperature is not exceeded. The average chip-junction temperature (TJ) in °C can be
obtained from:
The total power dissipation can be calculated from:
Two cases with internal voltage regulator enabled and disabled must be considered:
1. Internal Voltage Regulator disabled
Which is the sum of all output currents on I/O ports associated with VDDX and VDDM.
For RDSON is valid:
respectively
2. Internal voltage regulator enabled
IDDR is the current shown in Table A-8 and not the overall current flowing into VDDR, which
additionally contains the current flowing into the external loads with output high.
Which is the sum of all output currents on I/O ports associated with VDDX and VDDR.
TJTAPDΘJA
•()+=
TJJunction Temperature, [°C]=
TAAmbient Temperature, [°C]=
PDTotal Chip Power Dissipation, [W]=
ΘJA Package Thermal Resistance, [°C/W]=
PDPINT PIO
+=
PINT Chip Internal Power Dissipation, [W]=
PINT IDD VDD
⋅IDDPLL VDDPLL
⋅IDDA
+V
DDA
⋅+=
PIO RDSON
i
∑IIOi
2
⋅=
RDSON
VOL
IOL
------------ for outputs driven low;=
RDSON
VDD5 VOH
–
IOH
------------------------------------ for outputs driven high;=
PINT IDDR VDDR
⋅IDDA VDDA
⋅+=
PIO RDSON
i
∑IIOi
2
⋅=
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 653
Rev 01.24
Table A-5. Thermal Package Characteristics(1)
1. The values for thermal resistance are achieved by package simulations
Num C Rating Symbol Min Typ Max Unit
1 T Thermal Resistance LQFP48, single layer PCB(2)
2. PC Board according to EIA/JEDEC Standard 51-2
θJA ——69
oC/W
2T
Thermal Resistance LQFP48, double sided PCB
with 2 internal planes(3)
3. PC Board according to EIA/JEDEC Standard 51-7
θJA ——53
oC/W
3 T Junction to Board LQFP48 θJB ——30
oC/W
4 T Junction to Case LQFP48 θJC ——20
oC/W
5 T Junction to Package Top LQFP48 ΨJT —— 4
oC/W
6 T Thermal Resistance LQFP52, single sided PCB θJA ——65
oC/W
7T
Thermal Resistance LQFP52, double sided PCB
with 2 internal planes θJA ——49
oC/W
8 T Junction to Board LQFP52 θJB ——31
oC/W
9 T Junction to Case LQFP52 θJC ——17
oC/W
10 T Junction to Package Top LQFP52 ΨJT —— 3
oC/W
11 T Thermal Resistance QFP 80, single sided PCB θJA ——52
oC/W
12 T Thermal Resistance QFP 80, double sided PCB
with 2 internal planes θJA ——42
oC/W
13 T Junction to Board QFP80 θJB ——28
oC/W
14 T Junction to Case QFP80 θJC ——18
oC/W
15 T Junction to Package Top QFP80 ΨJT —— 4
oC/W
Appendix A Electrical Characteristics
654 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.1.9 I/O Characteristics
This section describes the characteristics of all I/O pins. All parameters are not always applicable, e.g. not
all pins feature pull up/down resistances.
Table A-6. 5V I/O Characteristics
Conditions are 4.5< VDDX <5.5V Temperature from –40˚C to +140˚C, unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 P Input High Voltage VIH 0.65*VDD5 ——V
T Input High Voltage VIH ——V
DD5 + 0.3 V
2 P Input Low Voltage VIL — — 0.35*VDD5 V
T Input Low Voltage VIL VSS5 - 0.3 — — V
3 C Input Hysteresis VHYS 250 — mV
4P
Input Leakage Current (pins in high ohmic input mode)(1)
Vin = VDD5 or VSS5
1. Maximum leakage current occurs at maximum operating temperature. Current decreases by approximately one-half for each
8 C to 12 C in the temperature range from 50 C to 125 C.
Iin —— 1µA
5C
Output High Voltage (pins in output mode)
Partial Drive IOH = –2mA VOH VDD5 – 0.8 — — V
6P
Output High Voltage (pins in output mode)
Full Drive IOH = –10mA VOH VDD5 – 0.8 — — V
7C
Output Low Voltage (pins in output mode)
Partial Drive IOL = +2mA VOL — — 0.8 V
8P
Output Low Voltage (pins in output mode)
Full Drive IOL = +10mA VOL — — 0.8 V
9P
Internal Pull Up Device Current,
tested at VIL Max. IPUL — — –130 µA
10 C Internal Pull Up Device Current,
tested at VIH Min. IPUH –10 — — µA
11 P Internal Pull Down Device Current,
tested at VIH Min. IPDH — — 130 µA
12 C Internal Pull Down Device Current,
tested at VIL Max. IPDL 10 — — µA
13 D Input Capacitance Cin —7 —pf
14 T
Injection current(2)
Single Pin limit
Total Device Limit. Sum of all injected currents
2. Refer to Section A.1.4, “Current Injection”, for more details
IICS
IICP
–2.5
–25
—
—
2.5
25
mΑ
15 P Port P, J Interrupt Input Pulse filtered(3)
3. Parameter only applies in STOP or Pseudo STOP mode.
tPIGN —— 3µs
16 P Port P, J Interrupt Input Pulse passed3tPVAL 10 — — µs
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 655
Rev 01.24
A.1.10 Supply Currents
This section describes the current consumption characteristics of the device as well as the conditions for
the measurements.
A.1.10.1 Measurement Conditions
All measurements are without output loads. Unless otherwise noted the currents are measured in single
chip mode, internal voltage regulator enabled and at 25MHz bus frequency using a 4MHz oscillator.
Table A-7. 3.3V I/O Characteristics
Conditions are VDDX=3.3V +/-10%, Temperature from –40˚C to +140˚C, unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 P Input High Voltage VIH 0.65*VDD5 ——V
T Input High Voltage VIH ——V
DD5 + 0.3 V
2 P Input Low Voltage VIL — — 0.35*VDD5 V
T Input Low Voltage VIL VSS5 – 0.3 — — V
3 C Input Hysteresis VHYS — 250 — mV
4P
Input Leakage Current (pins in high ohmic input mode)(1)
Vin = VDD5 or VSS5
1. Maximum leakage current occurs at maximum operating temperature. Current decreases by approximately one-half for each
8 C to 12 C in the temperature range from 50 C to 125 C.
Iin –1 — 1µA
5C
Output High Voltage (pins in output mode)
Partial Drive IOH = –0.75mA VOH VDD5 – 0.4 — — V
6P
Output High Voltage (pins in output mode)
Full Drive IOH = –4mA VOH VDD5 – 0.4 — — V
7C
Output Low Voltage (pins in output mode)
Partial Drive IOL = +0.9mA VOL — — 0.4 V
8P
Output Low Voltage (pins in output mode)
Full Drive IOL = +4.75mA VOL — — 0.4 V
9 P Internal Pull Up Device Current, tested at VIL Max. IPUL — — –60 µA
10 C Internal Pull Up Device Current, tested at VIH Min. IPUH -6 — — µA
11 P Internal Pull Down Device Current, tested at VIH Min. IPDH —— 60µA
12 C Internal Pull Down Device Current, tested at VIL Max. IPDL 6——µA
11 D Input Capacitance Cin —7 —πΦ
12 T
Injection current(2)
Single Pin limit
Total Device Limit. Sum of all injected currents
2. Refer to Section A.1.4, “Current Injection”, for more details
IICS
IICP
–2.5
–25
— 2.5
25
µΑ
13 P Port P, J Interrupt Input Pulse filtered(3)
3. Parameter only applies in STOP or Pseudo STOP mode.
tPIGN —— 3µs
14 P Port P, J Interrupt Input Pulse passed3tPVAL 10 — — µs
Appendix A Electrical Characteristics
656 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.1.10.2 Additional Remarks
In expanded modes the currents flowing in the system are highly dependent on the load at the address, data
and control signals as well as on the duty cycle of those signals. No generally applicable numbers can be
given. A very good estimate is to take the single chip currents and add the currents due to the external loads.
Table A-8. Supply Current Characteristics for MC9S12CG16 MC9S12C32
Conditions are shown in Table A-4 with internal regulator enabled unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 P Run Supply Current Single Chip IDD5 — — 35 mA
2P
P
C
Wait Supply current
All modules enabled
VDDR<4.9V, only RTI enabled2
VDDR>4.9V, only RTI enabled
IDDW
—
—
—
3.5
2.5
30
8mA
3
C
P
C
P
C
P
C
P
Pseudo Stop Current (RTI and COP disabled)23
–40°C
27°C
85°C
"C" Temp Option 100˚C
105°C
"V" Temp Option 120˚C
125°C
"M" Temp Option 140°C
IDDPS(1)
1. STOP current measured in production test at increased junction temperature, hence for Temp Option "C" the test is carried
out at 100˚C although the Temperature specification is 85˚C. Similarly for "v" and "M" options the temperature used in test lies
15˚C above the temperature option specification.
—
—
—
—
—
—
—
—
340
360
500
550
590
720
780
1100
—
450
—
1450
—
1900
—
4500
µA
4
C
C
C
C
C
Pseudo Stop Current (RTI and COP enabled)(2) (3)
–40°C
27°C
85°C
105°C
125°C
2. PLL off
3. At those low power dissipation levels TJ = TA can be assumed
IDDPS1
—
—
—
—
—
540
700
750
880
1300
—
—
—
—
—
µA
5
C
P
C
P
C
P
C
P
Stop Current 3
–40°C
27°C
85°C
"C" Temp Option 100˚C
105°C
"V" Temp Option 120˚C
125°C
"M" Temp Option 140°C
IDDS1
—
—
—
—
—
—
—
—
10
20
100
140
170
300
350
520
—
80
—
1000
—
1400
—
4000
µA
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 657
Rev 01.24
Table A-9. Supply Current Characteristics for Other Family Members
Conditions are shown in Table A-4 with internal regulator enabled unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 P Run Supply Current Single Chip, IDD5 — — 45 mA
2P
P
C
Wait Supply current
All modules enabled
VDDR<4.9V, only RTI enabled2
VDDR>4.9V, only RTI enabled
IDDW
—
—
—
—
2.5
3.5
33
8
—
mA
6
C
P
C
P
C
P
C
P
Pseudo Stop Current (RTI and COP disabled)23
–40°C
27°C
85°C
"C" Temp Option 100˚C
105°C
"V" Temp Option 120˚C
125°C
"M" Temp Option 140°C
IDDPS(1)
1. STOP current measured in production test at increased junction temperature, hence for Temp Option "C" the test is carried out
at 100˚C although the Temperature specification is 85˚C. Similarly for "v" and "M" options the temperature used in test lies
15˚C above the temperature option specification.
—
—
—
—
—
—
—
—
190
200
300
400
450
600
650
1000
—
250
—
1400
—
1900
—
4800
µA
4
C
C
C
C
C
Pseudo Stop Current (RTI and COP enabled)(2) (3)
–40°C
27°C
85°C
105°C
125°C
2. PLL off
3. At those low power dissipation levels TJ = TA can be assumed
IDDPS1
—
—
—
—
—
370
500
590
780
1200
—
—
—
—
—
µA
5
C
P
C
P
C
P
C
P
Stop Current 3
–40°C
27°C
85°C
"C" Temp Option 100˚C
105°C
"V" Temp Option 120˚C
125°C
"M" Temp Option 140°C
IDDS1
—
—
—
—
—
—
—
—
12
25
130
160
200
350
400
600
—
100
—
1200
—
1700
—
4500
µA
Appendix A Electrical Characteristics
658 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.2 ATD Characteristics
This section describes the characteristics of the analog-to-digital converter.
VRL is not available as a separate pin in the 48- and 52-pin versions. In this case the internal VRL pad is
bonded to the VSSA pin.
The ATD is specified and tested for both the 3.3V and 5V range. For ranges between 3.3V and 5V the ATD
accuracy is generally the same as in the 3.3V range but is not tested in this range in production test.
A.2.1 ATD Operating Characteristics In 5V Range
The Table A-10 shows conditions under which the ATD operates.
The following constraints exist to obtain full-scale, full range results: VSSA ≤VRL ≤VIN ≤VRH ≤VDDA.
This constraint exists since the sample buffer amplifier can not drive beyond the power supply levels that
it ties to. If the input level goes outside of this range it will effectively be clipped.
Table A-10. ATD Operating Characteristics
Conditions are shown in Table A-4 unless otherwise noted. Supply Voltage 5V-10% <= VDDA <=5V+10%
Num C Rating Symbol Min Typ Max Unit
1D
Reference Potential
Low
High
VRL
VRH
VSSA
VDDA/2
—
—
VDDA/2
VDDA
V
V
2 C Differential Reference Voltage(1)
1. Full accuracy is not guaranteed when differential voltage is less than 4.75V
VRH-VRL 4.75 5.0 5.25 V
3 D ATD Clock Frequency fATDCLK 0.5 — 2.0 MHz
4D
ATD 10-Bit Conversion Period
Clock Cycles(2)
Conv, Time at 2.0MHz ATD Clock fATDCLK
2. The minimum time assumes a final sample period of 2 ATD clocks cycles while the maximum time assumes a final sample
period of 16 ATD clocks.
NCONV10
TCONV10
14
7
—
—
28
14
Cycles
µs
5D
ATD 8-Bit Conversion Period
Clock Cycles2
Conv, Time at 2.0MHz ATD Clock fATDCLK
NCONV10
TCONV10
12
6
—
—
26
13
Cycles
µs
5 D Recovery Time (VDDA=5.0 Volts) tREC ——20µs
6 P Reference Supply current IREF — — 0.375 mA
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 659
Rev 01.24
A.2.2 ATD Operating Characteristics In 3.3V Range
The Table A-11 shows conditions under which the ATD operates.
The following constraints exist to obtain full-scale, full range results: VSSA ≤VRL ≤VIN ≤VRH ≤VDDA.
This constraint exists since the sample buffer amplifier can not drive beyond the power supply levels that
it ties to. If the input level goes outside of this range it will effectively be clipped
A.2.3 Factors Influencing Accuracy
Three factors — source resistance, source capacitance and current injection — have an influence on the
accuracy of the ATD.
A.2.3.1 Source Resistance
Due to the input pin leakage current as specified in Table A-6 in conjunction with the source resistance
there will be a voltage drop from the signal source to the ATD input. The maximum source resistance RS
specifies results in an error of less than 1/2 LSB (2.5mV) at the maximum leakage current. If device or
operating conditions are less than worst case or leakage-induced error is acceptable, larger values of source
resistance is allowable.
A.2.3.2 Source Capacitance
When sampling an additional internal capacitor is switched to the input. This can cause a voltage drop due
to charge sharing with the external and the pin capacitance. For a maximum sampling error of the input
voltage ≤ 1LSB, then the external filter capacitor, Cf≥ 1024 * (CINS – CINN).
Table A-11. ATD Operating Characteristics
Conditions are shown in Table A-4 unless otherwise noted; Supply Voltage 3.3V-10% <= VDDA <= 3.3V+10%
Num C Rating Symbol Min Typ Max Unit
1D
Reference Potential
Low
High
VRL
VRH
VSSA
VDDA/2
—
—
VDDA/2
VDDA
V
V
2 C Differential Reference Voltage VRH-VRL 3.0 3.3 3.6 V
3 D ATD Clock Frequency fATDCLK 0.5 — 2.0 MHz
4D
ATD 10-Bit Conversion Period
Clock Cycles(1)
Conv, Time at 2.0MHz ATD Clock fATDCLK
1. The minimum time assumes a final sample period of 2 ATD clocks cycles while the maximum time assumes a final sample
period of 16 ATD clocks.
NCONV10
TCONV10
14
7
—
—
28
14
Cycles
µs
5D
ATD 8-Bit Conversion Period
Clock Cycles1
Conv, Time at 2.0MHz ATD Clock fATDCLK
NCONV8
TCONV8
12
6
—
—
26
13
Cycles
µs
6 D Recovery Time (VDDA=3.3 Volts) tREC ——20µs
7 P Reference Supply current IREF — — 0.250 mA
Appendix A Electrical Characteristics
660 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.2.3.3 Current Injection
There are two cases to consider.
1. A current is injected into the channel being converted. The channel being stressed has conversion
values of $3FF ($FF in 8-bit mode) for analog inputs greater than VRH and $000 for values less
than VRL unless the current is higher than specified as disruptive conditions.
2. Current is injected into pins in the neighborhood of the channel being converted. A portion of this
current is picked up by the channel (coupling ratio K), This additional current impacts the accuracy
of the conversion depending on the source resistance.
The additional input voltage error on the converted channel can be calculated as VERR =K*R
S*
IINJ, with IINJ being the sum of the currents injected into the two pins adjacent to the converted
channel.
A.2.4 ATD Accuracy (5V Range)
Table A-12 specifies the ATD conversion performance excluding any errors due to current injection, input
capacitance and source resistance
.
Table 21-18. ATD Electrical Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1C
Max input Source Resistance RS—— 1KΩ
2T
Total Input Capacitance
Non Sampling
Sampling
CINN
CINS
—
—
—
—
10
15
pF
3C
Disruptive Analog Input Current INA –2.5 — 2.5 mA
4C
Coupling Ratio positive current injection Kp——
10-4 A/A
5C
Coupling Ratio negative current injection Kn——
10-2 A/A
Table A-12. ATD Conversion Performance
Conditions are shown in Table A-4 unless otherwise noted
VREF = VRH – VRL = 5.12V. Resulting to one 8 bit count = 20mV and one 10 bit count = 5mV
fATDCLK = 2.0MHz
Num C Rating Symbol Min Typ Max Unit
1 P 10-Bit Resolution LSB — 5 — mV
2 P 10-Bit Differential Nonlinearity DNL –1 — 1 Counts
3 P 10-Bit Integral Nonlinearity INL –2 — 2 Counts
4 P 10-Bit Absolute Error(1)
1. These values include quantization error which is inherently 1/2 count for any A/D converter.
AE -2.5 — 2.5 Counts
5 P 8-Bit Resolution LSB — 20 — mV
6 P 8-Bit Differential Nonlinearity DNL –0.5 — 0.5 Counts
7 P 8-Bit Integral Nonlinearity INL –1.0 ±0.5 1.0 Counts
8 P 8-Bit Absolute Error1AE -1.5 ±1 1.5 Counts
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 661
Rev 01.24
A.2.5 ATD Accuracy (3.3V Range)
Table A-13 specifies the ATD conversion performance excluding any errors due to current injection, input
capacitance and source resistance.
For the following definitions see also Figure A-1.
Differential Non-Linearity (DNL) is defined as the difference between two adjacent switching steps.
The Integral Non-Linearity (INL) is defined as the sum of all DNLs:
Table A-13. ATD Conversion Performance
Conditions are shown in Table A-4 unless otherwise noted
VREF = VRH - VRL = 3.328V. Resulting to one 8 bit count = 13mV and one 10 bit count = 3.25mV
fATDCLK = 2.0MHz
Num C Rating Symbol Min Typ Max Unit
1 P 10-Bit Resolution LSB — 3.25 — mV
2 P 10-Bit Differential Nonlinearity DNL –1.5 — 1.5 Counts
3 P 10-Bit Integral Nonlinearity INL –3.5 ±1.5 3.5 Counts
4 P 10-Bit Absolute Error(1)
1. These values include the quantization error which is inherently 1/2 count for any A/D converter.
AE –5 ±2.5 5 Counts
5 P 8-Bit Resolution LSB — 13 — mV
6 P 8-Bit Differential Nonlinearity DNL –0.5 — 0.5 Counts
7 P 8-Bit Integral Nonlinearity INL –1.5 ±1 1.5 Counts
8 P 8-Bit Absolute Error1AE –2.0 ±1.5 2.0 Counts
DNL i() ViVi1–
–
1LSB
---------------------------1–=
INL n() DNL i()
i1=
n
∑VnV0
–
1LSB
---------------------n–==
Appendix A Electrical Characteristics
662 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure A-1. ATD Accuracy Definitions
NOTE
Figure A-1 shows only definitions, for specification values refer to Table A-
12.
1
3.25 Vin
mV
6.5 9.75 13 16.25 19.5 22.75 26 3305 3309 3312 3315 3318 3321 3324 33283292 3295 3299 33023289
0
3
2
5
4
7
6
29.25
$3F7
$3F9
$3F8
$3FB
$3FA
$3FD
$3FC
$3FE
$3FF
$3F4
$3F6
$3F5
8
9
1
2
$FF
$FE
$FD
$3F3
10-Bit Resolution
8-Bit Resolution
Ideal Transfer Curve
10-Bit Transfer Curve
8-Bit Transfer Curve
3286
10-Bit Absolute Error Boundary
8-Bit Absolute Error Boundary
LSB
Vi-1 Vi
DNL
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 663
Rev 01.24
A.3 MSCAN
A.4 Reset, Oscillator and PLL
This section summarizes the electrical characteristics of the various startup scenarios for Oscillator and
Phase-Locked-Loop (PLL).
A.4.1 Startup
Table A-15 summarizes several startup characteristics explained in this section. Detailed description of the
startup behavior can be found in the Clock and Reset Generator (CRG) Block User Guide.
A.4.1.1 POR
The release level VPORR and the assert level VPORA are derived from the VDD supply. They are also valid
if the device is powered externally. After releasing the POR reset the oscillator and the clock quality check
are started. If after a time tCQOUT no valid oscillation is detected, the MCU will start using the internal self
clock. The fastest startup time possible is given by nuposc.
A.4.1.2 LVR
The release level VLVRR and the assert level VLVRA are derived from the VDD supply. They are also valid
if the device is powered externally. After releasing the LVR reset the oscillator and the clock quality check
are started. If after a time tCQOUT no valid oscillation is detected, the MCU will start using the internal self
clock. The fastest startup time possible is given by nuposc.
Table A-14. MSCAN Wake-up Pulse Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 P MSCAN Wake-up dominant pulse filtered tWUP —— 2 us
2 P MSCAN Wake-up dominant pulse pass tWUP 5——us
Table A-15. Startup Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 T POR release level VPORR — — 2.07 V
2 T POR assert level VPORA 0.97 — — V
3 D Reset input pulse width, minimum input time PWRSTL 2——t
osc
4 D Startup from Reset nRST 192 — 196 nosc
5D
Interrupt pulse width, IRQ edge-sensitive
mode PWIRQ 20 — — ns
6 D Wait recovery startup time tWRS — — 14 tcyc
Appendix A Electrical Characteristics
664 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.4.1.3 SRAM Data Retention
Provided an appropriate external reset signal is applied to the MCU, preventing the CPU from executing
code when VDD5 is out of specification limits, the SRAM contents integrity is guaranteed if after the reset
the PORF bit in the CRG Flags Register has not been set.
A.4.1.4 External Reset
When external reset is asserted for a time greater than PWRSTL the CRG module generates an internal
reset, and the CPU starts fetching the reset vector without doing a clock quality check, if there was an
oscillation before reset.
A.4.1.5 Stop Recovery
Out of STOP the controller can be woken up by an external interrupt. A clock quality check as after POR
is performed before releasing the clocks to the system.
A.4.1.6 Pseudo Stop and Wait Recovery
The recovery from Pseudo STOP and Wait are essentially the same since the oscillator was not stopped in
both modes. In Pseudo Stop Mode the voltage regulator is switched to reduced performance mode to
reduce power consumption. The returning out of pseudo stop to full performance takes tvup. The controller
can be woken up by internal or external interrupts.After twrs in Wait or tvup +t
wrs in Pseudo Stop the CPU
starts fetching the interrupt vector.
A.4.2 Oscillator
The device features an internal Colpitts and Pierce oscillator. The selection of Colpitts oscillator or Pierce
oscillator/external clock depends on the XCLKS signal which is sampled during reset. Pierce
oscillator/external clock mode allows the input of a square wave. Before asserting the oscillator to the
internal system clocks the quality of the oscillation is checked for each start from either power-on, STOP
or oscillator fail. tCQOUT specifies the maximum time before switching to the internal self clock mode after
POR or STOP if a proper oscillation is not detected. The quality check also determines the minimum
oscillator start-up time tUPOSC. The device also features a clock monitor. A Clock Monitor Failure is
asserted if the frequency of the incoming clock signal is below the Assert Frequency fCMFA.
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 665
Rev 01.24
Table A-16. Oscillator Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1a C Crystal oscillator range (Colpitts) fOSC 0.5 — 16 MHz
1b C Crystal oscillator range (Pierce) (1) 4
1. Depending on the crystal a damping series resistor might be necessary
fOSC 0.5 — 40 MHz
2 P Startup Current iOSC 100 — — µA
3 C Oscillator start-up time (Colpitts) tUPOSC —8
(2)
2. fosc = 4MHz, C = 22pF.
100(3)
3. Maximum value is for extreme cases using high Q, low frequency crystals
ms
4 D Clock Quality check time-out tCQOUT 0.45 — 2.5 s
5 P Clock Monitor Failure Assert Frequency fCMFA 50 100 200 KHz
6 P External square wave input frequency (4)
4. Only valid if Pierce Oscillator/external clock selected (XCLKS = 0 during reset)
fEXT 0.5 — 50 MHz
7 D External square wave pulse width low tEXTL 9.5 — — ns
8 D External square wave pulse width high tEXTH 9.5 — — ns
9 D External square wave rise time tEXTR —— 1ns
10 D External square wave fall time tEXTF —— 1ns
11 D Input Capacitance (EXTAL, XTAL pins) CIN —7—pF
12 C DC Operating Bias in Colpitts Configuration
on EXTAL Pin VDCBIAS — 1.1 — V
13 P EXTAL Pin Input High Voltage4
VIH,EXTAL
0.75*
VDDPLL
——V
T EXTAL Pin Input High Voltage4VIH,EXTAL ——V
DDPLL+0.3 V
14 P EXTAL Pin Input Low Voltage4
VIl,EXTAL ——
0.25*
VDDPLL
V
T EXTAL Pin Input Low Voltage4VIl,EXTAL VSSPLL-0.3 — — V
15 C EXTAL Pin Input Hysteresis4VHYS,EXTAL — 250 — mV
Appendix A Electrical Characteristics
666 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.4.3 Phase Locked Loop
The oscillator provides the reference clock for the PLL. The PLL´s Voltage Controlled Oscillator (VCO)
is also the system clock source in self clock mode.
A.4.3.1 XFC Component Selection
This section describes the selection of the XFC components to achieve a good filter characteristics.
Figure A-2. Basic PLL Functional Diagram
The following procedure can be used to calculate the resistance and capacitance values using typical values
for K1, f1 and ich from Table A-17.
The grey boxes show the calculation for fVCO = 50MHz and fref = 1MHz. E.g., these frequencies are used
for fOSC = 4MHz and a 25MHz bus clock.
The VCO Gain at the desired VCO frequency is approximated by:
The phase detector relationship is given by:
ich is the current in tracking mode.
fosc 1
refdv+1
fref
Phase
Detector
VCO
KV
1
synr+1
fvco
Loop Divider
KF
1
2
D
fcmp
Cs R
Cp
VDDPLL
XFC Pin
KVK1e
f1fvco
–()
K11V⋅
-----------------------
⋅=100–e
60 50–()
100–
----------------------
⋅=
= -90.48MHz/V
KΦich
–KV
⋅==316.7Hz/Ω
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 667
Rev 01.24
The loop bandwidth fCshould be chosen to fulfill the Gardner’s stability criteria by at least a factor of 10,
typical values are 50. ζ = 0.9 ensures a good transient response.
And finally the frequency relationship is defined as
With the above values the resistance can be calculated. The example is shown for a loop bandwidth
fC=10kHz:
The capacitance Cs can now be calculated as:
The capacitance Cp should be chosen in the range of:
A.4.3.2 Jitter Information
The basic functionality of the PLL is shown in Figure A-3. With each transition of the clock fcmp, the
deviation from the reference clock fref is measured and input voltage to the VCO is adjusted accordingly.
The adjustment is done continuously with no abrupt changes in the clock output frequency. Noise, voltage,
temperature and other factors cause slight variations in the control loop resulting in a clock jitter. This jitter
affects the real minimum and maximum clock periods as illustrated in Figure A-4.
fC
2ζfref
⋅⋅
πζ 1ζ2
++
⎝⎠
⎛⎞
⋅
------------------------------------------ 1
10
----- fC
fref
410⋅
-------------ζ0.9=();<→⋅<
fC < 25kHz
nfVCO
fref
------------- 2 s y n r 1+()⋅== = 50
R2πnf
C
⋅⋅⋅
KΦ
-----------------------------= =2*π*50*10kHz/(316.7Hz/Ω)=9.9kΩ=~10kΩ
Cs
2ζ2
⋅
πfCR⋅⋅
----------------------0.516
fCR⋅
---------------ζ0.9=();≈== 5.19nF =~ 4.7nF
Cs20⁄CpCs10⁄≤≤ Cp = 470pF
Appendix A Electrical Characteristics
668 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure A-3. Jitter Definitions
The relative deviation of tnom is at its maximum for one clock period, and decreases towards zero for larger
number of clock periods (N).
Defining the jitter as:
For N < 100, the following equation is a good fit for the maximum jitter:
Figure A-4. Maximum Bus Clock Jitter Approximation
This is very important to notice with respect to timers, serial modules where a pre-scaler will eliminate the
effect of the jitter to a large extent.
2 3 N-1 N1
0
tnom
tmax1
tmin1
tmaxN
tminN
JN() max 1 tmax N()
Nt
nom
⋅
---------------------
–1tmin N()
Nt
nom
⋅
---------------------
–,
⎝⎠
⎜⎟
⎛⎞
=
JN() j1
N
-------- j2
+=
1 5 10 20 N
J(N)
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 669
Rev 01.24
A.5 NVM, Flash, and EEPROM
A.5.1 NVM Timing
The time base for all NVM program or erase operations is derived from the oscillator. A minimum
oscillator frequency fNVMOSC is required for performing program or erase operations. The NVM modules
do not have any means to monitor the frequency and will not prevent program or erase operation at
frequencies above or below the specified minimum. Attempting to program or erase the NVM modules at
a lower frequency a full program or erase transition is not assured.
The Flash program and erase operations are timed using a clock derived from the oscillator using the
FCLKDIV and ECLKDIV registers respectively. The frequency of this clock must be set within the limits
specified as fNVMOP
.
The minimum program and erase times shown in Table A-18 are calculated for maximum fNVMOP and
maximum fbus. The maximum times are calculated for minimum fNVMOP and a fbus of 2MHz.
Table A-17. PLL Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 P Self Clock Mode frequency fSCM 1 — 5.5 MHz
2 D VCO locking range fVCO 8 — 50 MHz
3D
Lock Detector transition from Acquisition to Tracking
mode |∆trk| 3—4%
(1)
1. % deviation from target frequency
4 D Lock Detection |∆Lock| 0 — 1.5 %1
5 D Un-Lock Detection |∆unl| 0.5 — 2.5 %1
6D
Lock Detector transition from Tracking to Acquisition
mode |∆unt| 6—8%
1
7 C PLLON Total Stabilization delay (Auto Mode) (2)
2. fOSC = 4MHz, fBUS = 25MHz equivalent fVCO = 50MHz: REFDV = #$03, SYNR = #$018, Cs = 4.7nF, Cp = 470pF, Rs = 10KΩ.
tstab — 0.5 — ms
8 D PLLON Acquisition mode stabilization delay 2tacq — 0.3 — ms
9 D PLLON Tracking mode stabilization delay 2tal — 0.2 — ms
10 D Fitting parameter VCO loop gain K1— -100 — MHz/V
11 D Fitting parameter VCO loop frequency f1— 60 — MHz
12 D Charge pump current acquisition mode | ich | — 38.5 — µA
13 D Charge pump current tracking mode | ich | — 3.5 — µA
14 C Jitter fit parameter 12j1— — 1.1 %
15 C Jitter fit parameter 22j2— — 0.13 %
Appendix A Electrical Characteristics
670 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.5.1.1 Single Word Programming
The programming time for single word programming is dependant on the bus frequency as a well as on the
frequency f¨NVMOP and can be calculated according to the following formula.
A.5.1.2 Row Programming
Generally the time to program a consecutive word can be calculated as:
For the C16, GC16, C32 and GC32 device flash arrays, where up to 32 words in a row can be programmed
consecutively by keeping the command pipeline filled, the time to program a whole row is:
For the C64, GC64, C96, C128 and GC128 device flash arrays, where up to 64 words in a row can be
programmed consecutively by keeping the command pipeline filled, the time to program a whole row is:
Row programming is more than 2 times faster than single word programming.
A.5.1.3 Sector Erase
Erasing either a 512 byte or 1024 byte Flash sector takes:
The setup times can be ignored for this operation.
A.5.1.4 Mass Erase
Erasing a NVM block takes:
This is independent of sector size.
The setup times can be ignored for this operation.
tswpgm 91
fNVMOP
---------------------
⋅25 1
fbus
----------
⋅+=
tbwpgm 41
fNVMOP
---------------------
⋅91
fbus
----------
⋅+=
tbrpgm tswpgm 31 tbwpgm
⋅+=
tbrpgm tswpgm 63 tbwpgm
⋅+=
tera 4000 1
fNVMOP
---------------------
⋅≈
tmass 20000 1
fNVMOP
---------------------
⋅≈
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 671
Rev 01.24
Table A-18. NVM Timing Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
1 D External Oscillator Clock fNVMOSC 0.5 — 50(1)
1. Restrictions for oscillator in crystal mode apply!
MHz
2 D Bus frequency for Programming or Erase Operations fNVMBUS 1 — MHz
3 D Operating Frequency fNVMOP 150 — 200 kHz
4 P Single Word Programming Time tswpgm 46(2)
2. Minimum Programming times are achieved under maximum NVM operating frequency f NVMOP and maximum bus frequency
fbus.
— 74.5(3)
3. Maximum Erase and Programming times are achieved under particular combinations of f NVMOP and bus frequency f bus. Refer
to formulae in Sections A.3.1.1 - A.3.1.4 for guidance.
µs
5 D Flash Burst Programming consecutive word tbwpgm 20.42—31
3µs
6 D Flash Burst Programming Time for 32 Word row tbrpgm 678.42— 1035.53µs
6 D Flash Burst Programming Time for 64 Word row tbrpgm 1331.22— 2027.53µs
7 P Sector Erase Time tera 20(4)
4. Minimum Erase times are achieved under maximum NVM operating frequency f NVMOP
.
— 26.73ms
8 P Mass Erase Time tmass 1004— 1333ms
9 D Blank Check Time Flash per block t check 11(5)
5. Minimum time, if first word in the array is not blank (512 byte sector size).
— 32778(6)
6. Maximum time to complete check on an erased block (512 byte sector size)
(7)tcyc
7. Where tcyc is the system bus clock period.
9 D Blank Check Time Flash per block t check 11(8)
8. Minimum time, if first word in the array is not blank (1024 byte sector size)
— 65546(9)
9. Maximum time to complete check on an erased block (1024 byte sector size).
7tcyc
Appendix A Electrical Characteristics
672 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
A.5.2 NVM Reliability
The reliability of the NVM blocks is guaranteed by stress test during qualification, constant process
monitors and burn-in to screen early life failures. The program/erase cycle count on the sector is
incremented every time a sector or mass erase event is executed.
Table A-19. NVM Reliability Characteristics(1)
1. TJavg will not exeed 85°C considering a typical temperature profile over the lifetime of a consumer, industrial or automotive
application.
Conditions are shown in Table A-4. unless otherwise noted
Num C Rating Symbol Min Typ Max Unit
Flash Reliability Characteristics
1 C Data retention after 10,000 program/erase cycles at an
average junction temperature of TJavg ≤85°C
tFLRET 15 100(2)
2. Typical data retention values are based on intrinsic capability of the technology measured at high temperature and de-rated to
25°C using the Arrhenius equation. For additional information on how Freescale defines Typical Data Retention, please refer
to Engineering Bulletin EB618.
— Years
2 C Data retention with <100 program/erase cycles at an
average junction temperature TJavg ≤ 85°C
20 1002—
3 C Number of program/erase cycles
(–40°C≤ TJ≤ 0°C)
nFL 10,000 — — Cycles
4 C Number of program/erase cycles
(0°C≤ TJ≤ 140°C)
10,000 100,000(3)
3. Spec table quotes typical endurance evaluated at 25°C for this product family, typical endurance at various temperature can
be estimated using the graph below. For additional information on how Freescale defines Typical Endurance, please refer to
Engineering Bulletin EB619.
—
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 673
Rev 01.24
Figure A-5. Typical Endurance vs Temperature
A.6 SPI
This section provides electrical parametrics and ratings for the SPI.
In Table A-20 the measurement conditions are listed.
A.6.1 Master Mode
In Figure A-6 the timing diagram for master mode with transmission format CPHA=0 is depicted.
Table A-20. Measurement Conditions
Description Value Unit
Drive mode Full drive mode —
Load capacitance CLOAD, on all outputs 50 pF
Thresholds for delay measurement points (20% / 80%) VDDX V
Typical Endurance [103Cycles]
Operating Temperature TJ [°C]
0
50
100
150
200
250
300
350
400
450
500
-40 -20 0 20 40
60
80
100 120 140
------ Flash
Appendix A Electrical Characteristics
674 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure A-6. SPI Master Timing (CPHA=0)
In Figure A-7 the timing diagram for master mode with transmission format CPHA=1 is depicted.
Figure A-7. SPI Master Timing (CPHA=1)
SCK
(OUTPUT)
SCK
(OUTPUT)
MISO
(INPUT)
MOSI
(OUTPUT)
SS1
(OUTPUT)
1
9
5 6
MSB IN2
BIT 6 . . . 1
LSB IN
MSB OUT2LSB OUT
BIT 6 . . . 1
11
4
4
2
10
(CPOL = 0)
(CPOL = 1)
3
13
13
1. If configured as an output.
2. LSBF = 0. For LSBF = 1, bit order is LSB, bit 1, ..., bit 6, MSB.
12
12
SCK
(OUTPUT)
SCK
(OUTPUT)
MISO
(INPUT)
MOSI
(OUTPUT)
1
5 6
MSB IN2
BIT 6 . . . 1
LSB IN
MASTER MSB OUT2MASTER LSB OUT
BIT 6 . . . 1
4
4
9
12 13
11
PORT DATA
(CPOL = 0)
(CPOL = 1)
PORT DATA
SS1
(OUTPUT)
212 13 3
1. If configured as output
2. LSBF = 0. For LSBF = 1, bit order is LSB, bit 1, ..., bit 6, MSB.
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 675
Rev 01.24
In Table A-21 the timing characteristics for master mode are listed.
A.6.2 Slave Mode
In Figure A-8 the timing diagram for slave mode with transmission format CPHA=0 is depicted.
Figure A-8. SPI Slave Timing (CPHA=0)
Table A-21. SPI Master Mode Timing Characteristics
Num C Characteristic Symbol Min Typ Max Unit
1 P SCK Frequency fsck 1/2048 — 1/2f
bus
1 P SCK Period tsck 2 — 2048 tbus
2 D Enable Lead Time tlead — 1/2 — tsck
3 D Enable Lag Time tlag — 1/2 — tsck
4 D Clock (SCK) High or Low Time twsck — 1/2 — tsck
5 D Data Setup Time (Inputs) tsu 8——ns
6 D Data Hold Time (Inputs) thi 8——ns
9 D Data Valid after SCK Edge tvsck — — 30 ns
10 D Data Valid after SS fall (CPHA=0) tvss — — 15 ns
11 D Data Hold Time (Outputs) tho 20 — — ns
12 D Rise and Fall Time Inputs trfi —— 8 ns
13 D Rise and Fall Time Outputs trfo —— 8 ns
SCK
(INPUT)
SCK
(INPUT)
MOSI
(INPUT)
MISO
(OUTPUT)
SS
(INPUT)
1
9
5 6
MSB IN
BIT 6 . . . 1
LSB IN
SLAVE MSB SLAVE LSB OUT
BIT 6 . . . 1
11
4
4
2
7
(CPOL = 0)
(CPOL = 1)
3
13
NOTE: Not defined!
12
12
11
SEE
13
NOTE
8
10
see
note
Appendix A Electrical Characteristics
676 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
In Figure A-9 the timing diagram for slave mode with transmission format CPHA=1 is depicted.
Figure A-9. SPI Slave Timing (CPHA=1)
In Table A-22 the timing characteristics for slave mode are listed.
Table A-22. SPI Slave Mode Timing Characteristics
Num C Characteristic Symbol Min Typ Max Unit
1 D SCK Frequency fsck DC — 1/4f
bus
1 P SCK Period tsck 4— t
bus
2 D Enable Lead Time tlead 4——t
bus
3 D Enable Lag Time tlag 4——t
bus
4 D Clock (SCK) High or Low Time twsck 4——t
bus
5 D Data Setup Time (Inputs) tsu 8——ns
6 D Data Hold Time (Inputs) thi 8——ns
7 D Slave Access Time (time to data active) ta——20ns
8 D Slave MISO Disable Time tdis ——22ns
9D
Data Valid after SCK Edge tvsck ——
30 + tbus
(1)
1. tbus added due to internal synchronization delay
ns
10 D Data Valid after SS fall tvss — — 30 + tbus1ns
11 D Data Hold Time (Outputs) tho 20 — — ns
12 D Rise and Fall Time Inputs trfi —— 8 ns
13 D Rise and Fall Time Outputs trfo —— 8 ns
SCK
(INPUT)
SCK
(INPUT)
MOSI
(INPUT)
MISO
(OUTPUT)
1
5 6
MSB IN
BIT 6 . . . 1
LSB IN
MSB OUT SLAVE LSB OUT
BIT 6 . . . 1
4
4
9
12 13
11
(CPOL = 0)
(CPOL = 1)
SS
(INPUT)
212 13
3
NOTE: Not defined!
SLAVE
7
8
see
note
∞
Appendix A Electrical Characteristics
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 677
Rev 01.24
A.7 Voltage Regulator
A.7.1 Voltage Regulator Operating Conditions
A.7.2 Chip Power-up and LVI/LVR Graphical Explanation
Voltage regulator sub modules LVI (low voltage interrupt), POR (power-on reset) and LVR (low voltage
reset) handle chip power-up or drops of the supply voltage. Their function is described in Figure A-10.
Table A-23. Voltage Regulator Electrical Parameters
Num C Characteristic Symbol Min Typ Max Unit
1 P Input Voltages VVDDR, A 2.97 — 5.5 V
3P
Output Voltage Core
Full Performance Mode VDD 2.35 2.5 2.75 V
4P
Low Voltage Interrupt(1)
Assert Level (xL45J mask set)
Assert Level (other mask sets)
Deassert Level (xL45J mask set)
Deassert Level (other mask sets)
1. Monitors VDDA, active only in Full Performance Mode. Indicates I/O & ADC performance degradation due to low supply voltage.
VLVIA
VLVIA
VLVID
VLVID
4.30
4.00
4.42
4.15
4.53
4.37
4.65
4.52
4.77
4.66
4.89
4.77
V
V
V
V
5P
Low Voltage Reset(2),(3)
Assert Level (xL45J mask set)
Assert Level (other mask sets)
2. Monitors VDD, active only in Full Performance Mode. MCU is monitored by the POR in RPM (see Figure A-10)
3. Digital functionality is guaranteed in the range between VDD(min) and VLVRA(min).
VLVRA 2.25
2.25
2.3
2.35
—
—
V
7C
Power-on Reset(4)
Assert Level
Deassert Level
4. Monitors VDD. Active in all modes.
VPORA
VPORD
0.97
—
—
—
—
2.05
V
V
Appendix A Electrical Characteristics
678 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Figure A-10. Voltage Regulator — Chip Power-up and Voltage Drops (not scaled)
A.7.3 Output Loads
A.7.3.1 Resistive Loads
The on-chip voltage regulator is intended to supply the internal logic and oscillator circuits allows no
external DC loads.
A.7.3.2 Capacitive Loads
The capacitive loads are specified in Table A-24. Ceramic capacitors with X7R dielectricum are required.
Table A-24. Voltage Regulator — Capacitive Loads
Num Characteristic Symbol Min Typical Max Unit
1V
DD external capacitive load CDDext 400 440 12000 nF
2V
DDPLL external capacitive load CDDPLLext 90 220 5000 nF
VLVID
VLVIA
VLVRD
VLVRA
VPORD
LVI
POR
LVR
t
VVDDA
VDD
LVI enabled LVI disabled due to LVR
Appendix B Emulation Information
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 679
Rev 01.24
Appendix B
Emulation Information
B.1 General
For emulation, external addressing of a 128K memory map is required. This is provided in a 112 LQFP
package version of the MC9S12C128 which includes the 3 necessary extra external address bus signals via
Port K. This package version is for emulation only and not provided as a general production package.
Figure B-1. Pin Assignments in 112-Pin LQFP
VRH
VDDA
NC
PAD07/AN07
NC
PAD06/AN06
NC
PAD05/AN05
NC
PAD04/AN04
NC
PAD03/AN03
NC
PAD02/AN02
NC
PAD01/AN01
NC
PAD00/AN00
VSS2
VDD2
PA7/ADDR15/DATA15
PA6/ADDR14/DATA14
PA5/ADDR13/DATA13
PA4/ADDR12/DATA12
PA3/ADDR11/DATA11
PA2/ADDR10/DATA10
PA1/ADDR9/DATA9
PA0/ADDR8/DATA8
PP4/KWP4/PW4
PP5/KPW5/PWM
NC
PP7/KWP7/PW7
NC
VDDX
VSSX
PM0/RXCAN
PM1/TXCAN
PM2/MIS
PM3/SS
PM4/MOSI
PM5/SCK
PJ6/KWJ6
PJ7/KWJ7
NC
NC
PP6/KWP6/ROMONE
NC
NC
PS3
PS2
PS1/TXD
PS0/RXD
NC
NC
VSSA
VRL
PW3/KWP3/PP3
PW2/KWP2/PP2
PW1/KWP1/PP1
/PW0/KWP0/PP0
NC
XADDR16/PK2
XADDR15/PK1
XADDR14/PK0
IOC0/PT0
IOC1/PT1
IOC2/PT2
IOC3/PT3
VDD1
VSS1
IOC4/PT4
IOC5/PT5
IOC6/PT6
IOC7/PT7
NC
NC
NC
NC
MODC/TAGHI/BKGD
ADDR0/DATA0/PB0
ADDR1/DATA1/PB1
ADDR2/DATA2/PB2
ADDR3/DATA3/PB3
ADDR4/DATA4/PB4
ADDR5/DATA5/PB5
ADDR6/DATA6/PB6
ADDR7/DATA7/PB7
NC
NC
NC
NC
XCLKS/NOACC/PE7
MODB/IPIPE1/PE6
MODA/IPIPE0/PE5
ECLK/PE4
VSSR
VDDR
RESET
VDDPLL
XFC
VSSPLL
EXTAL
XTAL
TEST
NC
NC
NC
NC
LSTRB/TAGLO/PE3
R/W/PE2
IRQ/PE1
XIRQ/PE0
Signals shown in Bold are available only in the 112 Pin Package. Pins marked "NC" are not connected
MC9S12C128
112
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
Appendix B Emulation Information
680 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
B.1.1 PK[2:0] / XADDR[16:14]
PK2-PK0 provide the expanded address XADDR[16:14] for the external bus.
Refer to the S12 Core user guide for detailed information about external address page access.
The reset state of DDRK in the S12_CORE is $00, configuring the pins as inputs.
The reset state of PUPKE in the PUCR register of the S12_CORE is "1" enabling the internal pullup
resistors at PortK[2:0].
In this reset state the pull-up resistors provide a defined state and prevent a floating input, thereby
preventing unnecessary current consumption at the input stage.
Pin Name
Function 1
Pin Name
Function 2 Power Domain
Internal Pull
Resistor
Description
CTRL Reset
State
PK[2:0] XADDR[16:14] VDDX PUPKE Up Port K I/O Pins
Appendix C Package Information
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 681
Rev 01.24
Appendix C
Package Information
C.1 General
This section provides the physical dimensions of the packages 48LQFP, 52LQFP, 80QFP.
Appendix C Package Information
682 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
C.1.1 80-Pin QFP Package
Figure C-1. 80-Pin QFP Mechanical Dimensions (Case no. 841B)
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DATUM PLANE -H- IS LOCATED AT BOTTOM OF
LEAD AND IS COINCIDENT WITH THE
LEAD WHERE THE LEAD EXITS THE PLASTIC
BODY AT THE BOTTOM OF THE PARTING LINE.
4. DATUMS -A-, -B- AND -D- TO BE
DETERMINED AT DATUM PLANE -H-.
5. DIMENSIONS S AND V TO BE DETERMINED
AT SEATING PLANE -C-.
6. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION. ALLOWABLE
PROTRUSION IS 0.25 PER SIDE. DIMENSIONS
A AND B DO INCLUDE MOLD MISMATCH
AND ARE DETERMINED AT DATUM PLANE -H-.
7. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.08 TOTAL IN
EXCESS OF THE D DIMENSION AT MAXIMUM
MATERIAL CONDITION. DAMBAR CANNOT
BE LOCATED ON THE LOWER RADIUS OR
THE FOOT.
SECTION B-B
61
60
DETAIL A
L
41
40
80
-A-
L
-D-
A
S
A-B
M
0.20 D S
H
0.05 A-B
S
120
21
-B-
BV
J
F
N
D
VIEW ROTATED 90 °
DETAIL A
B
BP
-A-,-B-,-D-
E
H
G
M
M
DETAIL C
SEATING
PLANE
-C-
CDATUM
PLANE
0.10
-H-
DATUM
PLANE -H-
U
T
R
Q
K
W
X
DETAIL C
DIM MIN MAX
MILLIMETERS
A13.90 14.10
B13.90 14.10
C2.15 2.45
D0.22 0.38
E2.00 2.40
F0.22 0.33
G0.65 BSC
H--- 0.25
J0.13 0.23
K0.65 0.95
L12.35 REF
M510
N0.13 0.17
P0.325 BSC
Q07
R0.13 0.30
S16.95 17.45
T0.13 ---
U0 ---
V16.95 17.45
W0.35 0.45
X1.6 REF
°°
°°
°
S
A-B
M
0.20 D S
C
S
A-B
M
0.20 D S
H
0.05 D
S
A-B
M
0.20 D S
C
S
A-B
M
0.20 D S
C
Appendix C Package Information
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 683
Rev 01.24
C.1.2 52-Pin LQFP Package
Figure C-2. 52-Pin LQFP Mechanical Dimensions (Case no. 848D-03)
F
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982.
CONTROLLING DIMENSION: MILLIMETER
DATUM PLANE -H- IS LOCATED AT BOTTOM OF LEAD AND IS COINCIDENT
WITH THE LEAD WHERE THE LEAD EXITS THE PLASTIC BODY AT THE
BOTTOM OF THE PARTING LINE.
2. DATUMS -L-, -M- AND -N- TO BE DETERMINED AT DATUM PLANE -H-.
DIMENSIONS S AND V TO BE DETERMINED AT SEATING PLANE -T-.
DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION.
ALLOWABLE PROTRUSION IS 0.25 (0.010) PER SIDE. DIMENSIONS A AND
B DO INCLUDE MOLD MISMATCH AND ARE DETERMINED AT DATUM
PLANE -H-
DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. DAMBAR
PROTRUSION SHALL NOT CAUSE THE LEAD WIDTH TO EXCEED 0.46
(0.018). MINIMUM SPACE BETWEEN PROTRUSION AND ADJACENT LEAD
OR PROTRUSION 0.07 (0.003).
VIEW AA
AB
AB
VIEW Y
SECTION AB-AB
ROTATED 90 ° CLOCKWISE
DIM
A
MIN MAX MIN MAX
INCHES
10.00 BSC 0.394 BSC
MILLIMETERS
A1 5.00 BSC 0.197 BSC
B10.00 BSC 0.394 BSC
B1 5.00 BSC 0.197 BSC
C--- 1.70 --- 0.067
C1 0.05 0.20 0.002 0.008
C2 1.30 1.50 0.051 0.059
D0.20 0.40 0.008 0.016
E0.45 0.030
F0.22 0.35 0.009 0.014
G0.65 BSC
0.75 0.018
0.026 BSC
J0.07 0.20 0.003 0.008
K0.50 REF 0.020 REF
R1 0.08 0.20 0.003 0.008
S12.00 BSC 0.472 BSC
S1 6.00 BSC 0.236 BSC
U0.09 0.16 0.004 0.006
V12.00 BSC 0.472 BSC
V1 6.00 BSC 0.236 BSC
W0.20 REF 0.008 REF
Z1.00 REF 0.039 REF
C
L
-X-
X=L, M, N
1
13
14 26
27
39
4052
4X 13 TIPS
4X
N0.20 (0.008) H L-M N0.20 (0.008) T L-M
SEATING
PLANE
C0.10 (0.004) T
4X θ3
4X θ2
S
0.05 (0.002)
0.25 (0.010)
GAGE PLANE
C2
C1
W
K
E
Z
S
L-M
M
0.13 (0.005) N
S
T
PLATING
BASE METAL
D
JU
B V
B1
A
S
V1
A1
S1
-L-
-N-
-M-
-H-
-T-
θ1
θ
G
θ1
θ
θ3
θ2
07
°°
12
°
07
°°
0
°
0
°
--- ---
REF 12
°
REF
3X
VIEW Y
VIEW AA
2X R
R1
12
°
REF 12
°
REF
Appendix C Package Information
684 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
C.1.3 48-Pin LQFP Package
Figure C-3. 48-Pin LQFP Mechanical Dimensions (Case no. 932-03 issue F)
A
A1
Z
0.200 AB T-U
4X
Z0.200 AC T-U
4X
B
B1
1
12
13 24
25
36
37
48
S1
S
V
V1
P
AE AE
T, U, Z
DETAIL Y
DETAIL Y
BASE METAL
NJ
F
D
T-U
M
0.080 ZAC
SECTION AE-AE
AD
G0.080 AC
M°
TOP & BOTTOM
L°
W
K
AA
E
C
H
0.250
R
9
DETAIL AD
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ASME Y14.5M, 1994.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DATUM PLANE AB IS LOCATED AT BOTTOM
OF LEAD AND IS COINCIDENT WITH THE
LEAD WHERE THE LEAD EXITS THE PLASTIC
BODY AT THE BOTTOM OF THE PARTING
LINE.
4. DATUMS T, U, AND Z TO BE DETERMINED AT
DATUM PLANE AB.
5. DIMENSIONS S AND V TO BE DETERMINED
AT SEATING PLANE AC.
6. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION. ALLOWABLE
PROTRUSION IS 0.250 PER SIDE. DIMENSIONS
A AND B DO INCLUDE MOLD MISMATCH AND
ARE DETERMINED AT DATUM PLANE AB.
7. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. DAMBAR PROTRUSION SHALL
NOT CAUSE THE D DIMENSION TO EXCEED
0.350.
TU
Z
AB
AC
GAUGE PLANE
DIM
A
MIN MAX
7.000 BSC
MILLIMETERS
A1 3.500 BSC
B7.000 BSC
B1 3.500 BSC
C1.400 1.600
D0.170 0.270
E1.350 1.450
F0.170 0.230
G0.500 BSC
H0.050 0.150
J0.090 0.200
K0.500 0.700
M12 REF
N0.090 0.160
P0.250 BSC
L07
R0.150 0.250
S9.000 BSC
S1 4.500 BSC
V9.000 BSC
V1 4.500 BSC
W0.200 REF
AA 1.000 REF
°
°°
Appendix D Derivative Differences
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 685
Rev 01.24
Appendix D
Derivative Differences
The Device User Guide provides information about the MC9S12C-Family and the MC9S12GC-Family.
The C-Family and the GC-Family offer an extensive range of package, temperature and speed options.
The members of the GC-Family are a subset of the C-family that do not feature a CAN module.
Table D-1. shows a feature overview of the C and GC family members.
Table D-1. List of MC9S12C and MC9S12GC Family members(1)
1. All family memebers are available in 80QFP, 52LQFP and 48LQFP package options
Flash RAM Device CAN SCI SPI A/D PWM Timer
128K 4K MC9S12C128 1 1 1 8ch 6ch 8ch
MC9S12GC128 — 1 1 8ch 6ch 8ch
96K 4K MC9S12C96 1 1 1 8ch 6ch 8ch
MC9S12GC96 — 1 1 8ch 6ch 8ch
64K 4K MC9S12C64 1 1 1 8ch 6ch 8ch
MC9S12GC64 — 1 1 8ch 6ch 8ch
32K 2K MC9S12C32 1 1 1 8ch 6ch 8ch
MC9S12GC32 — 1 1 8ch 6ch 8ch
16K 1K MC9S12GC16 — 1 1 8ch 6ch 8ch
Appendix E Ordering Information
686 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
Appendix E
Ordering Information
Figure E-1. Order Part number Coding
Table E-1. lists C-family part number coding based on package, speed and temperature and die options.
Table E-2. lists CG-family part number coding based on package, speed and temperature and die options.
Table E-1. MC9S12C-Family / MC9S12GC-Family Part Number Coding
Part Number Mask(1)
set Temp. Package Speed Die Type Flash RAM I/O(2),
(3)
MC9S12C128CFA XL09S/0M66G -40˚C, 85˚C 48LQFP 25MHz C128 die 128K 4K 31
MC9S12C128CPB XL09S/0M66G -40˚C, 85˚C 52LQFP 25MHz C128 die 128K 4K 35
MC9S12C128CFU XL09S/0M66G -40˚C, 85˚C 80QFP 25MHz C128 die 128K 4K 60
MC9S12C128VFA XL09S/0M66G -40˚C,105˚C 48LQFP 25MHz C128 die 128K 4K 31
MC9S12C128VPB XL09S/0M66G -40˚C,105˚C 52LQFP 25MHz C128 die 128K 4K 35
MC9S12C128VFU XL09S/0M66G -40˚C, 105˚C 80QFP 25MHz C128 die 128K 4K 60
MC9S12C128MFA XL09S/0M66G -40˚C,125˚C 48LQFP 25MHz C128 die 128K 4K 31
MC9S12C128MPB XL09S/0M66G -40˚C,125˚C 52LQFP 25MHz C128 die 128K 4K 35
MC9S12C128MFU XL09S/0M66G -40˚C, 125˚C 80QFP 25MHz C128 die 128K 4K 60
MC9S12C96CFA XL09S/0M66G -40˚C, 85˚C 48LQFP 25MHz C128 die 96K 4K 31
MC9S12C96CPB XL09S/0M66G -40˚C, 85˚C 52LQFP 25MHz C128 die 96K 4K 35
MC9S12C96CFU XL09S/0M66G -40˚C, 85˚C 80QFP 25MHz C128 die 96K 4K 60
MC9S12C96VFA XL09S/0M66G -40˚C,105˚C 48LQFP 25MHz C128 die 96K 4K 31
MC9S12C96VPB XL09S/0M66G -40˚C,105˚C 52LQFP 25MHz C128 die 96K 4K 35
MC9S12C96VFU XL09S/0M66G -40˚C, 105˚C 80QFP 25MHz C128 die 96K 4K 60
MC9S12C96MFA XL09S/0M66G -40˚C,125˚C 48LQFP 25MHz C128 die 96K 4K 31
MC9S12C96MPB XL09S/0M66G -40˚C,125˚C 52LQFP 25MHz C128 die 96K 4K 35
MC9S12C96MFU XL09S/0M66G -40˚C, 125˚C 80QFP 25MHz C128 die 96K 4K 60
MC9S12C64CFA XL09S/0M66G -40˚C, 85˚C 48LQFP 25MHz C128 die 64K 4K 31
MC9S12C64CPB XL09S/0M66G -40˚C, 85˚C 52LQFP 25MHz C128 die 64K 4K 35
MC9S12 C32 C FU(E) 25
Package Option
Temperature Option
Device Title
Controller Family
Temperature Options
C = -40˚C to 85˚C
V = -40˚C to 105˚C
M = -40˚C to 125˚C
Package Options
FU = 80QFP
PB = 52LQFP
FA = 48LQFP
Speed Option
Speed Options
25 = 25MHz bus
16 = 16MHz bus
Environment Option
E = Environmentally
Package
Preferred
Environment Option
Appendix E Ordering Information
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 687
Rev 01.24
Table E-2. MC9S12GC-Family Part Number Coding
MC9S12C64CFU XL09S/0M66G -40˚C, 85˚C 80QFP 25MHz C128 die 64K 4K 60
MC9S12C64VFA XL09S/0M66G -40˚C,105˚C 48LQFP 25MHz C128 die 64K 4K 31
MC9S12C64VPB XL09S/0M66G -40˚C,105˚C 52LQFP 25MHz C128 die 64K 4K 35
MC9S12C64VFU XL09S/0M66G -40˚C, 105˚C 80QFP 25MHz C128 die 64K 4K 60
MC9S12C64MFA XL09S/0M66G -40˚C,125˚C 48LQFP 25MHz C128 die 64K 4K 31
MC9S12C64MPB XL09S/0M66G -40˚C,125˚C 52LQFP 25MHz C128 die 64K 4K 35
MC9S12C64MFU XL09S/0M66G -40˚C, 125˚C 80QFP 25MHz C128 die 64K 4K 60
MC9S12C32CFA16 xL45J / xM34C -40˚C, 85˚C 48LQFP 16MHz C32 die 32K 2K 31
MC9S12C32CPB16 xL45J / xM34C -40˚C, 85˚C 52LQFP 16MHz C32 die 32K 2K 35
MC9S12C32CFU16 xL45J / xM34C -40˚C, 85˚C 80QFP 16MHz C32 die 32K 2K 60
MC9S12C32VFA16 xL45J / xM34C -40˚C,105˚C 48LQFP 16MHz C32 die 32K 2K 31
MC9S12C32VPB16 xL45J / xM34C -40˚C,105˚C 52LQFP 16MHz C32 die 32K 2K 35
MC9S12C32VFU16 xL45J / xM34C -40˚C, 105˚C 80QFP 16MHz C32 die 32K 2K 60
MC9S12C32MFA16 xL45J / xM34C -40˚C,125˚C 48LQFP 16MHz C32 die 32K 2K 31
MC9S12C32MPB16 xL45J / xM34C -40˚C,125˚C 52LQFP 16MHz C32 die 32K 2K 35
MC9S12C32MFU16 xL45J / xM34C -40˚C, 125˚C 80QFP 16MHz C32 die 32K 2K 60
MC9S12C32CFA25 xL45J / xM34C -40˚C, 85˚C 48LQFP 25MHz C32 die 32K 2K 31
MC9S12C32CPB25 xL45J / xM34C -40˚C, 85˚C 52LQFP 25MHz C32 die 32K 2K 35
MC9S12C32CFU25 xL45J / xM34C -40˚C, 85˚C 80QFP 25MHz C32 die 32K 2K 60
MC9S12C32VFA25 xL45J / xM34C -40˚C,105˚C 48LQFP 25MHz C32 die 32K 2K 31
MC9S12C32VPB25 xL45J / xM34C -40˚C,105˚C 52LQFP 25MHz C32 die 32K 2K 35
MC9S12C32VFU25 xL45J / xM34C -40˚C, 105˚C 80QFP 25MHz C32 die 32K 2K 60
MC9S12C32MFA25 xL45J / xM34C -40˚C,125˚C 48LQFP 25MHz C32 die 32K 2K 31
MC9S12C32MPB25 xL45J / xM34C -40˚C,125˚C 52LQFP 25MHz C32 die 32K 2K 35
MC9S12C32MFU25 xL45J / xM34C -40˚C, 125˚C 80QFP 25MHz C32 die 32K 2K 60
1. XL09S denotes all minor revisions of L09S maskset
XL45J denotes all minor revisions of L45J maskset
Maskset dependent errata can be accessed at
http://e-www.motorola.com/wbapp/sps/site/prod_summary.jsp
2. All C-Family derivatives feature 1 CAN, 1 SCI, 1 SPI, an 8-channel A/D, a 6-channel PWM and an 8 channel timer.
The GC-Family members do not have the CAN module
3. I/O is the sum of ports able to act as digital input or output.
Part Number Mask(1)
set Temp. Package Speed Die Type Flash RAM I/O(2),
(3)
MC9S12GC32CFA xL45J / xM34C -40˚C, 85˚C 48LQFP 25MHz C32 die 32K 2K 31
MC9S12GC32CPB xL45J / xM34C -40˚C, 85˚C 52LQFP 25MHz C32 die 32K 2K 35
MC9S12GC32CFU xL45J / xM34C -40˚C, 85˚C 80QFP 25MHz C32 die 32K 2K 60
MC9S12GC32VFA xL45J / xM34C -40˚C,105˚C 48LQFP 25MHz C32 die 32K 2K 31
MC9S12GC32VPB xL45J / xM34C -40˚C,105˚C 52LQFP 25MHz C32 die 32K 2K 35
MC9S12GC32VFU xL45J / xM34C -40˚C, 105˚C 80QFP 25MHz C32 die 32K 2K 60
MC9S12GC32MFA xL45J / xM34C -40˚C,125˚C 48LQFP 25MHz C32 die 32K 2K 31
MC9S12GC32MPB xL45J / xM34C -40˚C,125˚C 52LQFP 25MHz C32 die 32K 2K 35
Part Number Mask(1)
set Temp. Package Speed Die Type Flash RAM I/O(2),
(3)
Appendix E Ordering Information
688 MC9S12C-Family / MC9S12GC-Family Freescale Semiconductor
Rev 01.24
MC9S12GC32MFU xL45J / xM34C -40˚C, 125˚C 80QFP 25MHz C32 die 32K 2K 60
MC9S12GC16CFA xL45J / xM34C -40˚C, 85˚C 48LQFP 25MHz C32 die 16K 1K 31
MC9S12GC16CPB xL45J / xM34C -40˚C, 85˚C 52LQFP 25MHz C32 die 16K 1K 35
MC9S12GC16CFU xL45J / xM34C -40˚C, 85˚C 80QFP 25MHz C32 die 16K 1K 60
MC9S12GC16VFA xL45J / xM34C -40˚C,105˚C 48LQFP 25MHz C32 die 16K 1K 31
MC9S12GC16VPB xL45J / xM34C -40˚C,105˚C 52LQFP 25MHz C32 die 16K 1K 35
MC9S12GC16VFU xL45J / xM34C -40˚C, 105˚C 80QFP 25MHz C32 die 16K 1K 60
MC9S12GC16MFA xL45J / xM34C -40˚C,125˚C 48LQFP 25MHz C32 die 16K 1K 31
MC9S12GC16MPB xL45J / xM34C -40˚C,125˚C 52LQFP 25MHz C32 die 16K 1K 35
MC9S12GC16MFU xL45J / xM34C -40˚C, 125˚C 80QFP 25MHz C32 die 16K 1K 60
1. XL09S denotes all minor revisions of L09S maskset
XL45J denotes all minor revisions of L45J maskset
Maskset dependent errata can be accessed at
http://e-www.motorola.com/wbapp/sps/site/prod_summary.jsp
2. All C-Family derivatives feature 1 CAN, 1 SCI, 1 SPI, an 8-channel A/D, a 6-channel PWM and an 8 channel timer. The
GC-Family members do not have the CAN module
3. I/O is the sum of ports capable to act as digital input or output.
Part Number Mask(1)
set Temp. Package Speed Die Type Flash RAM I/O(2),
(3)
How to Reach Us:
Home Page:
www.freescale.com
USA/Europe or Locations Not Listed:
Freescale Semiconductor
Technical Information Center, CH370
1300 N. Alma School Road
Chandler, Arizona 85224
1-800-521-6274 or 480-768-2130
Europe, Middle East, and Africa:
+44 1296 380 456 (English)
+46 8 52200080 (English)
+49 89 92103 559 (German)
+33 1 69 35 48 48 (French)
Japan:
Freescale Semiconductor Japan Ltd.
Technical Information Center
3-20-1, Minami-Azabu, Minato-ku
Tokyo 106-0047, Japan
0120-191014 or +81-3-3440-3569
Asia/Pacific:
Freescale Semiconductor Hong Kong Ltd.
Technical Information Center
2 Dai King Street
Tai Po Industrial Estate
Tai Po, N.T., Hong Kong
852-26668334
For Literature Requests Only:
Freescale Semiconductor Literature Distribution Center
P.O. Box 5405
Denver, Colorado 80217
1-800-441-2447 or 303-675-2140
Fax: 303-675-2150
Freescale™ and the Freescale logo are trademarks of Freescale
Semiconductor, Inc. All other product or service names are the property
of their respective owners. .
© Freescale Semiconductor, Inc. 2006. All rights reserved.
MC9S12C128
Rev 01.24
05/2010
Information in this document is provided solely to enable system and
software implementers to use Freescale Semiconductor products. There are
no express or implied copyright licenses granted hereunder to design or
fabricate any integrated circuits or integrated circuits based on the
information in this document.
Freescale Semiconductor reserves the right to make changes without further
notice to any products herein. Freescale Semiconductor makes no warranty,
representation or guarantee regarding the suitability of its products for any
particular purpose, nor does Freescale Semiconductor assume any liability
arising out of the application or use of any product or circuit, and specifically
disclaims any and all liability, including without limitation consequential or
incidental damages. “Typical” parameters that may be provided in Freescale
Semiconductor data sheets and/or specifications can and do vary in different
applications and actual performance may vary over time. All operating
parameters, including “Typicals”, must be validated for each customer
application by customer’s technical experts. Freescale Semiconductor does
not convey any license under its patent rights nor the rights of others.
Freescale Semiconductor products are not designed, intended, or authorized
for use as components in systems intended for surgical implant into the body,
or other applications intended to support or sustain life, or for any other
application in which the failure of the Freescale Semiconductor product could
create a situation where personal injury or death may occur. Should Buyer
purchase or use Freescale Semiconductor products for any such unintended
or unauthorized application, Buyer shall indemnify and hold Freescale
Semiconductor and its officers, employees, subsidiaries, affiliates, and
distributors harmless against all claims, costs, damages, and expenses, and
reasonable attorney fees arising out of, directly or indirectly, any claim of
personal injury or death associated with such unintended or unauthorized
use, even if such claim alleges that Freescale Semiconductor was negligent
regarding the design or manufacture of the part.
