Vybrid ProcessorsのトピックRe: Vybrid DMA Request from GPIO Input

Vybrid DMA Request from GPIO Input

nathanb_ — Fri, 14 Aug 2015 14:24:15 GMT

Hello All,

I'm currently trying to trigger a DMA request from an external GPIO input (PORT2[2]).

I can mux the GPIO input, and set the PCR->IRQC to 0xA and I get an interrupt generated no problem.

However, when I set the PCR->IRQC to 0x2, I never get a DMA request signal from DMA request source 41.

If I change the DMA request source to 24 (a flextimer I currently have running in DMA mode ), the DMA works correctly.

Does anyone know what's going on here? Can anyone confirm that DMA requests from GPIO inputs correctly function?

Thanks.

nathanb_ — Fri, 14 Aug 2015 14:38:04 GMT

Oddly enough, I changed the request source to 40 and now it works.

However, PORT2[2] is PTD28.

Source 40 is PORT C in the manual.

Any clarity?

alejandrolozan1 — Tue, 18 Aug 2015 21:28:40 GMT

Hi,

It is not stated in the documentation but according to my tests it seems that the Table 3-2 is not correct.

The PORTA -PORTE should be PORT0-PORT4. With that modification the Table 3-31 matches and corresponds to the behavior you are facing.

As you can see PORT2[2] corresponds to PTD28 but at the end it belongs to PORT2 and DMA source 40 corresponds.

Best Regards,

Alejandro

nathanb_ — Wed, 19 Aug 2015 11:44:23 GMT

Thanks Alejandro,

This is what I was suspecting when I tried 40.