UART problem - RRDY never set

Altera_Forum · ‎11-09-2009

I have a simple polled UART application which is not working as I expect:

rs232_rx_control = IORD_ALTERA_AVALON_UART_STATUS(UART_BASE);

if (rs232_rx_control & ALTERA_AVALON_UART_STATUS_RRDY_MSK)

{

*pBuffer = IORD_ALTERA_AVALON_UART_RXDATA(UART_BASE);

return 1;

}

The baud rate is 57600 and I am generating the characters manually, so speed isn't the problem.

The problem is that RRDY is never being set. The characters are being received into RXDATA. They overwrite the previous received character.

I don't see any receiver overruns, framing errors or detected breaks.

Transmitting characters is no problem for me.

Altera_Forum · ‎11-09-2009

Maybe looked at the others bits of the status register (PE, FE, BRK) to see if the error doesn't come from here.

Altera_Forum · ‎11-10-2009

Solved this myself.

I hadn't initialised the UART control register. I guess the default is to enable interrupts.

With all interrupts disabled the code worked as expected.

Altera_Forum · ‎11-10-2009

Solved this myself.

I hadn't initialised the UART control register. I guess the default is to enable interrupts.

With all interrupts disabled the code worked as expected.

Altera_Forum · ‎07-27-2011

hey bmarshall,

I'm facing the same problem, can you tell me how you initialised the UART control register and disabled interrupts.

Thanx,

Marek

Altera_Forum · ‎08-08-2011

I've been on vacation.

I no longer have this code. Current version is interrupt driven.

Altera_Forum · ‎08-09-2011

No problem, I ended up understanding your previous post. By disabling the interrupts in the control register I got the code to work as expected.

Regards,

Marek