PDM to PCM -- where does it happen?

There have been several threads on this forum asking where the PDM-PCM conversion occurs, how to adjust the sample rate, etc. This doesn’t seem to have been addressed.

(see: http://community.matrix.one/search?q=PDM%20category%3A1)

The User Constraint File (creator.ucf) for the FPGA has the lines for PDM mic data commented out.

I also could not find an microphone related code in the MCU codebase.

Can you please give us an overview of how the audio samples move from the MEM mics to the Pi and where the PDM-PCM occurs.