DMA1 Stream7 DMA2 Stream7

[StanCosgrove]

Hi I m using SPI DMA on H7 series, and notice under SPIx_TX and SPIx_RX there are at least 14 DMA channels to choose from, i.e DMA1 Stream 0-7 and DMA2 0-7. Can i select these "channel"  randomly or is there a reference manual that state otherwise? Likewise i saw the same case in USART DMA too, anyone can advise?

[waclawek.jan]

Older STM32 have a fixed connection from peripherals to individual DMA Channel/Stream. 'H7 does have DMAMUX though, read DMAMUX chapter in RM.

JW

[StanCosgrove]

ok, which RM document to check DMAMUX? i m looking at 750 reference manual but its not stated there...kindly advise thx.

[LCE]

For H723 - H735 it's chapter 17 in the reference manual (RM), directly after DMA chapters.

You can (almost) freely assign the DMA streams ( = channels), just check that the DMA can access the memory area (here: chapter 2: Memory and bus architecture ).

And mind that the lower channel number, the higher the priority in case of equal prio register setting.

[SofLit]

Hello,

There is also the AN5224 "STM32 DMAMUX: the DMA request router".