2019-05-19 02:33 PM
I'm working on a board where SAI1 is wired to a DAC. I've had it working using HAL calls, from a wavetable in RAM. But it needs to play back audio from USB. I tried various approaches; no luck. I was pointed at:
STM32Cube_FW_F7_V1.15.0\Projects\STM32746G-Discovery\Applications\USB_Device\AUDIO_Standalone
This uses SAI2. I have this dev board; I compiled it and ran it; it wasn't perfect (some scratchiness), but was close enough. But it uses the SAI Driver, not the HAL calls.
I ported it to my board, changing only SAI2 to SAI1 (and the CPU); doesn't work. Tried various other approaches, same result. No output - no clocks, nothing - from the SAI1 block.
Under debug, watching the registers, I see SAI1 B registers being setup. I need SAI1 A. Is there a bug in the driver? If not, what am I missing?
I could, I guess, re-use my original HAL-based code - but the USB interface code is more complex than I have time to analyse.
Steve