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| author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2010-08-20 21:22:27 +0000 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2010-08-20 21:22:27 +0000 |
| commit | 8affb5a9ed3661f67c8394094df617d004a19334 (patch) | |
| tree | 188819f5aeb0aa92c18e100032a0c44984a77fee /c/src/lib/libbsp/lm32/milkymist/Documentation/uart.txt | |
| parent | 2010-08-20 Joel Sherrill <joel.sherrill@oarcorp.com> (diff) | |
| download | rtems-8affb5a9ed3661f67c8394094df617d004a19334.tar.bz2 | |
2010-08-20 <yann.sionneau@telecom-sudparis.eu>
Add Milkymist BSP developed as part of GSOC 2010.
* ChangeLog, Makefile.am, README, bsp_specs, configure.ac,
preinstall.am, Documentation/uart.txt, include/.cvsignore,
include/bsp.h, include/system_conf.h, include/tm27.h,
make/custom/milkymist.cfg, startup/linkcmds: New files.
Diffstat (limited to 'c/src/lib/libbsp/lm32/milkymist/Documentation/uart.txt')
| -rw-r--r-- | c/src/lib/libbsp/lm32/milkymist/Documentation/uart.txt | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/lm32/milkymist/Documentation/uart.txt b/c/src/lib/libbsp/lm32/milkymist/Documentation/uart.txt new file mode 100644 index 0000000000..b5b93043e9 --- /dev/null +++ b/c/src/lib/libbsp/lm32/milkymist/Documentation/uart.txt @@ -0,0 +1,31 @@ +Initialization : + + set the CSR_UART_DIVISOR to the correct VALUE, + depending on the internal frequency of the LatticeMico32 softcore. + + for the ML401 board, this value is calculated using this formula : clk_frequency/230400/16 + clk_frequency = 100000000 Hz + => we must set CSR_UART_DIVISOR to 27 + +How to send a byte to uart : + +void writechar(char c) +{ + CSR_UART_RXTX = c; + while(!(irq_pending() & IRQ_UARTTX)); + irq_ack(IRQ_UARTTX); +} + +How to receive a byte from uart : + + +char readchar() +{ + char c; + while(!(irq_pending() & IRQ_UARTRX)); + irq_ack(IRQ_UARTRX); + c = CSR_UART_RXTX; + return c; +} + + |