So that now I have the processor running full-blast at 120MHz, it’s time to get the audio stuff working. It didn’t take long, really. I just had to get the right multiplication and division factors in place, turn on the I2S peripheral and configure it (only two registers), and then enable the “alternate function” for the pins that I used to interface to the audio codec chip. And here’s what I get:
The 11.2896MHz MCLK signal, which is 256x the audio sampling rate (44.1kHz):
The 44.1kHz LRC (left/right clock) or frame clock:
Now to wire up the audio codec and try to speak with it via I2C. Perhaps I’ll start with my brand new Bus Pirate, then move on to doing it from the STM32.