Interrupts problem

[electroRF]

Hi folks
I'd appreciate your kind support.

I'm running several DMA channels, sometimes on parallel.

Inside the ISR, at its beginning, I read the DMA Interrupts Register to know which channel has interrupted, then clear the HW Interrupt Source, which is connected from the uC to the DMA, and then treat the interrupting channel accordingly.

However, there was a special case where while I treated Channel A inside the ISR, another Channel, B, has interrupted, but since I already read the DMA Interrupts Register before Channel B's interrupt occurred, I did not treat Channel's B interrupt when I left the ISR.

Of course, I could re-read the DMA Interrupts Register at the end as well, however, there could still be a case where just after re-read it, another channel interrupts.

How then could I treat this special case?

Thank you.

 

[heydonms]

Without knowing exactly what processor you are using it is hard to say, but as a general rule each DMA device should have its own interrupt flag (you say "several DMA channels...in parallel" you don't mean they are sharing interrupts do you?).

You should be able to check the flags at the start of the ISR, clear just that flag and perform the necessary tasks. If you return from the interrupt when a flag is still set, it should generate another interrupt.