Vybrid DMA Request from GPIO Input

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Vybrid DMA Request from GPIO Input

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nathanb_
Contributor III

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.

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alejandrolozan1
NXP Employee
NXP Employee

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

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nathanb_
Contributor III

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?

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alejandrolozan1
NXP Employee
NXP Employee

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

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nathanb_
Contributor III

Thanks Alejandro,

This is what I was suspecting when I tried 40.

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