STM32F446: SAI1-B and UART4 simultaneous usage problem

[Ulrich Bruch]

Posted on May 23, 2017 at 14:17

Hi there,

i have the following issue:

Part: STM32F446V

HAL: Cube32MX, Version 1.16.0

I use SAI1-A with an ADC to sample audio signals (Stereo, 24Bit, 24kHz).

An Audio-DAC is connected to the SAI1-B. The SAI-B generates a waveform via DMA in circular mode. 

This works well but - when using UART4 (for debugging), 

the SAI1-B is not working. SAI1-A is still working.

As long, as i don´t call the function HAL_UART_Transmit(), everything works as expected. After calling this function (the UART4 works as expected), the SAI1-B stops generating it´s signals.

Maybe someone of you can bring some light to this?

Many thanks in advance,

Uli

[waclawek.jan]

Posted on May 23, 2017 at 16:01

I'd compare content of the relevant registers (SAI, GPIO, maybe RCC?) before and after the 'event'.

JW