XS1 audio - clocks generation problem

Discussions about USB Audio on XMOS devices
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XS1 audio - clocks generation problem

Post by genap »

I have XS1-U8A usb audio (TDM8, inputs only, 48kHz) project with the XMOS as a master.
Most of the time LR and BCLK are generated properly on power-up (pic 1).
But sometimes on power-up the LR frequency is about 45.2kHz instead of 48, with some jitter.
I've noticed that in this case the first bit in each 32-bit channel is longer (high level is 5 times longer than normal, occasionally jumping to 4 times, therefore is jitter).
It makes LR pulse longer and LR frequency lower. See pics 2 and 3.
I had quite a few XS1 audio projects, but never saw anything like this.
Is there any explanation to this situation?
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Post by Ross »

Did you resolve this?