USART Interrupt

srikanth_cg · **Joined:** Fri Aug 06, 2004 9:06 am **Posts:** 3

Hi All,

I am looking at AT91RM9200 datasheets and I had some questions
regarding the USART interrupts.

I do the following in my code.

Code:

// Enable USART interrupts
AIC_IER = 1 << AT91C_US1_ID;

// Register interrupt handler
AIC_SVR[AT91C_US1_ID] = usart_interrupt_handler;

// Enable RxReady and TxReady interrupt
US1_IER = AT91C_US_RXRDY | AT91C_US_TXRDY;

What will happen if I do the following?

// Set the USART interrupt in the AIC Interrupt Set Command Register
AIC_ISCR = AT91C_US1_ID;

Will the USART interrupt be generated? What value will the USART
Channel status register be holding? (AT91C_US1_CSR)

Thanks,
Srikanth

srikanth_cg · **Joined:** Fri Aug 06, 2004 9:06 am **Posts:** 3

I guess my question was clear enough.

Just to add little more info to it. Since all UART interrupts are handled by only one ISR, when I set the AIC_ISCR, what interrupt will I be able to detect in my ISR.

Thanks,
Srikanth

kowalczyk_michal · **Joined:** Sun Feb 06, 2005 9:01 pm **Posts:** 2

hello

Nothing will happend. USART will work properly. You should make an experiment. Try to set an interrupt from IRQ0 line on falling edge. Then try to set AIC_ICCR. You will see that interupt occurs continual. That does not concern USART. I have try it many times and USART was working no matter AIC_ICCR or AIC_ISCR.

any other questions? -> kowalczyk_michal@wp.pl

best regards
Michal Kowalczyk
POLAND

USART Interrupt

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