stm32h7 fastest gpio read using DMA

JLope.11 · ‎2024-04-12

I would like read the gpio lines at fastest speed.

As example it is possible to read first 4 ports by reading:

uint16_t ports0123=GPIOC->IDR&0x000F; (it is very fast, takes 28 tics)
It is possible to read ports GPIO_PIN_0-15 by connecting GPIOC->IDR to a DMA?

and a fast DMA?

waclawek.jan · ‎2024-04-12

You can do it, but you may be unpleasantly surprised by how slow it is.

While that article talks about toggling (i.e. write), most of what's written there applies to reads, too.

You may try to experiment with the BDMA which in the same clock domain as GPIO, but don't have too high expectations.

JW

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mƎALLEm · ‎2024-04-12

Hello

It is possible to read ports GPIO_PIN_0-15 by connecting GPIOC->IDR to a DMA?

Nothing prevents you to do it.

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waclawek.jan · ‎2024-04-12

You can do it, but you may be unpleasantly surprised by how slow it is.

While that article talks about toggling (i.e. write), most of what's written there applies to reads, too.

You may try to experiment with the BDMA which in the same clock domain as GPIO, but don't have too high expectations.

JW