i.MX RT1176 trigger memory to memory DMA using falling edge of GPIO

[brian_strickler]

Is it possible to trigger a DMA using the falling edge of a GPIO on the i.MX RT1176 without the need for software activating the DMA transfer?

I am seeking an alternative method to avoid processor intervention to service an interrupt upon the falling edge of a GPIO and activate a DMA transfer in software. It appears this may be possible with the XBAR. I'd imagine I would configure DMA0 CH0 to be triggered by DMAMUX0_XBAR1_Event0. However, I'm not sure how I would tie the GPIO's falling edge to trigger the XBAR1_Event0. Would any XBARA1->IN pin be able to be routed to this XBAR1_Event0? If so, how would this be implemented?

Please advise if this is remotely the right idea or if there is a more elegant way to simply trigger a memory-to-memory DMA transfer using the falling edge of a GPIO.

[Pavel_Hernandez]

Hello, sorry for the late response I was researching more information, the XBAR needs the input, and the output for the output as you know could be the XBAR1_OUT0 DMA, but for the input maybe you could use the IOMUX_XBAR_INOUTxx. 

But I recommend using the interrupt as normal and, in the handler, put the request of the DMA I believe this is the faster method.

Best regards,
Pavel

[Pavel_Hernandez]

Hello, my name is Pavel, and I will be supporting your case, let me get into your case and when I have more information, I will contact you.

Best regards,
Pavel