STM32H747: SAI with DMA on M7 core causes gaps in I2S stream, works fine on M4

[TG808]

Hi everyone,

I'm working on a project based on the following STM32H7 LwIP example:
https://github.com/stm32-hotspot/STM32H7-LwIP-Examples/tree/main/STM32H747_Disco_M7_ETH

In addition to the Ethernet functionality, I’ve enabled the SAI peripheral with DMA to transmit audio via I2S. I’ve noticed a problem:

When I run the SAI with DMA on the Cortex-M7 core using FreeRTOS, the audio stream contains gaps or dropouts.

However, when I move the exact same SAI/DMA initialization and logic to the Cortex-M4 core, the audio output is perfect with no gaps.
Has anyone experienced similar issues when using DMA for audio on the M7 core with FreeRTOS?

Any suggestions would be greatly appreciated.

Thanks in advance!
TG808

[Saket_Om]

Hello @TG808 

Could you run your code without FreeRTOS and LWIP and check if the issue is still there?

Did you refer to the example below and get inspired from it: 

STM32CubeH7/Projects/STM32H735G-DK/Examples/SAI/SAI_AudioPlay at master · STMicroelectronics/STM32CubeH7 · GitHub

[Neitekiller]

Hi TG808,

Did you have any success in solving this problem? I am currently using the SAI configured in Master receive for I2S on a H7 and am facing the same problem.