So I have a design where we're pulling audio sources into ADC0 and ADC1, Additionally, I've two channels of I2S connected to SDATA_IN0. The DSP is the master, and has its LRCLK and BCLK on MP10 and 11 tied back to the LRCLK and BCLK inputs on MP4 and MP5 and to the external ADC. The external ADC and the DSP are both driven off of buffered MCLK signals from the same osc.
The DSP appears to be outputting the proper LRCLK and BCLK signals, and the external ADC appears to be putting I2S signal onto MP0/SDATA_IN0. All the signals appear good on the scope, but in my Sigma Studio project, I can see signals presented to ADC0 & 1, but signals appear flat lined coming from the Input block Pins 2 & 3 (SDATA_IN0). Everything appears set up correctly, but I don't seem to be getting my I2S input into the DSP.
So I moved on to bring up a second board, and this one worked correctly, so the issue must have been a bad part on the first board.