People, please do forgive me if I'm wrong - my head hurts, have been debugging all day long and I may have found the problem! See pevious threads related to UART interrupts. I think I never acknowledged the interrupt because
void UART_ClearITPendingBit(UART_TypeDef* UARTx, u16 UART_IT) { /* Clear the specified interrupt */ UARTx->ICR &= UART_IT; }
does not write a 1 to acknowledge the receive interrupt if ICR is already 0 when the call occurs. if you do this:
UART0->ICR = 0x10 ;
the interrupt is acknowledge (yes, I know this might overwrite other bits...) Please forgive me if I oversee something (did read the specification, too much actually...), I am "kapoot" but happy I managed to more on a little!
Per, the purpose of the "ClearITPendingBit" is to clear a flag, including the interrupt receive flag. the point is, that clearing the interrupt occurs by writing a "1" (see STR9 datasheet :) ). it should be a logical OR instead of a AND. but guess what I found in the latest library downloaded from ST's site?
void UART_ClearITPendingBit(UART_TypeDef* UARTx, u16 UART_IT) { /* Clear the specified interrupt */ UARTx->ICR = UART_IT; }
not good yet, but will work a little better. that's it. I'm going to bed!
I disagree, the ST library as I see it is correct - It makes sense to write:
UARTx->ICR = UART_IT
and not logical or (read/write instruction seq.)
writing the location does exactly what the manual says - SET the BIT to clear the flag - by doing an 'OR' operation, you may pick up other flags and clear those as well when not intending to.