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A Maq
Associate III
Jun 22, 2019 11:22 AM UTC
Solved

STM32H743 BDMA channel for SAI4 not described in Manual

I am trying to program BDMA of STM32H743 using Nucleo board to perform DMA Peripheral to Memory operation .

What I have found a bit difficult is that I could not see any information on Reference Manual , Datasheet or on forum for the mapping information of basic DMA (BDMA) channels for SAI4 block A peripheral of STM32H7 MCU.

What I can see is the only Request ID mapping for DMAMUX2 which is 15 in this case.

Can anyone please help me to identify which channel should I use if I am trying to use SAI4_a BDMA?

This topic has been closed for replies.
A Maq
A MaqBest answer
Associate III
Jun 25, 2019 7:10 PM UTC

I have found channel for SAI-4_a of STM32H743 as channel_1 from an example provided by ST but still could not find the information for mapping in any of the document I have so far seen.

4 replies

A Maq
A MaqAuthorBest answer
Associate III
Jun 25, 2019 7:10 PM UTC

I have found channel for SAI-4_a of STM32H743 as channel_1 from an example provided by ST but still could not find the information for mapping in any of the document I have so far seen.

waclawek.jan
Super User
Jun 25, 2019 9:29 PM UTC

0690X000008jCFqQAM.png

And then it's you who says to which DMA channel will this request be directed, by setting the number of these requests to DMAMUX2_CxCR.DMAREQ_ID for the selected channel x.

Read the DMAMUX chapter in the RM.

JW

A Maq
A MaqAuthor
Associate III
Jun 26, 2019 2:19 AM UTC

Hi Jan,

Thanks for your response . Looking at the image you provided it only tells DMAMux2 input as 15 for Sai4_a but no mapping showed for input 15 to channel. It says DMAMux2 , channel 0 to 7 connected to BDMA channel 0 to 7​.

Where is input 15 mapped to channel that bit is confusing as putting in on channel 1 seems to be working. ​

waclawek.jan
Super User
Jun 26, 2019 12:07 PM UTC

As I've said above, you map it in by setting a chosen DMAMUX2_CxCR.DMAREQ_ID to 15.

JW