24 channels of audio over USB

Technical discussions around xCORE processors (e.g. xcore-200 & xcore.ai).
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genap
Experienced Member
Posts: 99
Joined: Sat Aug 31, 2013 11:23 pm

24 channels of audio over USB

Post by genap »

hello,
we have a new design requiring streaming of 24 channels of 24 bit, 48 KHz audio over USB.
In our previous designs, implemented on XS1-U8A, we had 6 (multiple I2S), 8 (TDM8) and 16 (TDM16) channels of audio.
In a new design we need to use both TDM16 and TDM8 to input audio to the chip for 24 channels streaming.
Is it possible to accomplish it with XU216 (or better yet, with XU208) ?
Any recommendations ?

I can't get any answers from XMOS at this time.

Will highly appreciate any advice.
Gennady


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akp
XCore Expert
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Joined: Thu Nov 26, 2015 11:47 pm

Post by akp »

XU216 can easily do 3 lanes of TDM8 if that's a possibility. That might be the easiest way to get 24 channels. Is it necessary to mix TDM16 and TDM8? I'd say it's likely not an deal-breaker but you'd have to do more software work rather than using the existing, working TDM code. You'd have to have 2 TDM BCLKs and 2 TDM lanes, so 1 BCLK and 3 TDM lanes would use the same number of IO anyway.

I can't speak to XU208 but a single TDM master doesn't use more than a core if that so it wouldn't surprise me (not having looked into the USB code).
genap
Experienced Member
Posts: 99
Joined: Sat Aug 31, 2013 11:23 pm

Post by genap »

thank you akr,

I have single TDM8 and TDM16 designs on XS1-U8A, so XU208 should probably be fine.
And the reason for TDM16+TDM8 comes from a DSP (signal source) ports mapping.
I think it will be easier (and significantly less time consuming) to use two XU208 chips (one for TDM16, one for TDM8) and just pass it to the hub (I have one on a board).

Thank you again,
Gennady
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