Support for 192k spdif rx

[Roblof]

I'm slightly confused about 192k support for spdif rx as I see references to both 96k and 192k.. Can the startkit and/or the explorerkit support this sample rate?

What about the audio kit?

Tnx!

[henk]

Hi Roblof,

192 is right on the edge.

Optical transport can change the duty cycle significantly; and this causes problems during signal recovery. Depending on the amount of jitter introduced by the transmitter, the signal may or may not be recovered correctly.

Coax hardly changes the duty cycle, and I belief that that works fine.

Neither startkit nor the explorer hit has an S/PDIF connector (of either type); and you would have to put one on one of the 1-bit I/O ports.

Cheers,
Henk

[larry]

Yes, duty cycle distortion can be too much over optical (it's actually a combination of receiver and transmitter that determines how much distortion will the processor see) at 192kHz. Optical 96kHz should be ok.

[Roblof]

Tnx guys!

I've always thought that optical was the most stable one. Do you have any links so that I can read up on this?

Is the regeneration of the clock for spdif/aes3 rx the reason why i2s seem to be more plausible at 192k?

I'm looking at this project https://www.xcore.com/forum/viewtopic.php?f=3&t=3427 and would like to bypass the aes3<-->i2s conversion as this seems like an unnecessary extra step.

[larry]

IEC 60958 is relevant. There are copies to be found online.

Also, this page has information on jitter specification:

http://www.epanorama.net/documents/audio/spdif.html