7
ATSTK94
2309B–FPSLI–01/02
RS232-compatible
UARTs
The RS232-compatible UARTs allow for communication between the two on-board
UARTs through the null-modem cable. It is also possible for communication between
the UARTs and other devices, such as your PC, by using a simple terminal program.
UART Connections The 2 UART connections, see Table 6, are made to DB9 connectors. Printf commands
are sent out on UART 0.
Multiple Clocks There are multiple clock circuits on the Starter Kit. A Manual Clock or the 4 MHz Oscilla-
tor are connected to 2 of the FPGA Global Clock pins. The 32,768 KHz (for the
implementation of the Real Time Clock calculations), 4 MHz, or 18.432 MHz can be
used to drive the AVR. The FPGA has 8 Global Clocks, 2 of these (GCLK5 and GCLK6)
can also be driven from the AVR system Clock. GCLK6 can alternatively be driven from
the Watchdog timer or one of the timer counters. For full details on the Clock circuits in
the FPSLIC device please refer to the AT94K datasheet available on the Atmel web site,
at http://www.atmel.com/atmel/acrobat/doc1138.pdf.
Table 6. UART Connections
UART Source /Destination Pin Hardware Settings
UART 0 RX0 140 Connect Cable to UART0
UART 0 TX0 141 Connect Cable to UART 0
UART1 RX1 149 Connect Cable to UART 1
UART1 TX1 150 Connect Cable to UART 1
Table 7. Clock Connections
Frequency Destination Pin Hardware Settings
Manual Clock FPGA GCLK7 162 Use MAN CLK Switch (SW9)
to Pulse Clock
Available Global
Clocks
FPGA GCLK1
FPGA GCLK2
FPGA GCLK3
FPGA GCLK4
FPGA GCLK7
FPGA GCLK8
4
47
57
100
162
204
32,768 KHz Crystal AVR TOSC 1 147 None
4 MHz Oscillator AVR System Clock 138 For Rev2 –JP17 towards side of
board, JP18 is unconnected.
For Rev3 and beyond –Position of
JP17 is changed, it is aligned with
FPGA and AVR jumpers. JP17 is
connected towards the inner side of
the board, JP18 is unconnected.
18.432 MHz Crystal AVR System Clock 138 For Rev2 –JP17 towards middle of
board, JP18 connected.
For Rev3 and beyond –Position of
JP17 is changed, it is aligned with
FPGA and AVR jumpers. JP17 is
connected towards the edge of the
board, JP18 is connected.