Hi,

I am working on software for a specific board, running linux 2.6.16 and own applications on a at91rm200.
In a new hw revision the usart0 was added. I changed the serial ports in the board file (board-ek.c ...) accordingly and the device occurs promptly in the /sys file system. Also the traffic is monitorable on /proc/tty/drivers/ttyS.

But I can not see any signal on the device pin PA17 aka txd0.

I set the uart0 in loopback mode and I saw the correct behaviour, the transmitted characters could be received by software.

Are there any circumstances I have to take care off ?
Thanks for the answer.

Best regards
dwuser

Hi,

the reason was simple - the original linux kernel implementation for the Evalboard-at91rm9200 uses the PA17 as input of the mmc write protect line.
So this pin was re-programmed as input.

After removing this behaviour all is fine with usart0.

Best regards
dwuser