XS1 audio - clocks generation problem

Discussions about USB Audio on XMOS devices
Experienced Member
Posts: 99
Joined: Sat Aug 31, 2013 11:23 pm

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?
You do not have the required permissions to view the files attached to this post.
User avatar
XCore Expert
Posts: 981
Joined: Thu Dec 10, 2009 9:20 pm
Location: Bristol, UK

Post by Ross »

Did you resolve this?