I build a USB->I2S->DAC based on the CM6631A into a PCM1794A. It works well.
I later picked up a Moonshadow XMOS USB board. I couldn't make the i2s work (no audio output at all). I've now measured the i2s clock lines as:
CM6631A
LRCK -> 44.1Hz
SCK -> 11.23MHz
BCK -> 5.64MHz
XMOS
LRCK -> 44.1Hz
MCK -> 22.72MHz
BCK -> 2.8MHz
You'll notice the XMOS doesn't have a SCK output but originally I thought MCK was just another naming convention.
Any i2s experts out there willing to drop a clue?
I later picked up a Moonshadow XMOS USB board. I couldn't make the i2s work (no audio output at all). I've now measured the i2s clock lines as:
CM6631A
LRCK -> 44.1Hz
SCK -> 11.23MHz
BCK -> 5.64MHz
XMOS
LRCK -> 44.1Hz
MCK -> 22.72MHz
BCK -> 2.8MHz
You'll notice the XMOS doesn't have a SCK output but originally I thought MCK was just another naming convention.
Any i2s experts out there willing to drop a clue?