USB Audio Reference Design SPDIF clocking alternative

Technical discussions related to any XMOS development kit or reference design. Eg XK-1A, sliceKIT, etc.
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eladmmor
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USB Audio Reference Design SPDIF clocking alternative

Post by eladmmor »

Hey there!
I am implementing an audio board based on the reference design.
I am changing the clock generation for the SPDIF signal clock encoding to oscillator ICs instead of the crystals,
which are used in the reference design.

Do I still need the Schmitt-trigger(U12) that is feeded with the MCLK signal and given to the XMOS?
What is the purpose of this component?

Thanks!


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Ross
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Post by Ross »

The only purpose of this part is a buffer.
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eladmmor
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Post by eladmmor »

Thanks for your reply Ross.

Would you happen to know why the Flip-flop that is used to encode the clock to the SPDIF signal (U1) is clocked using the unbuffered version of MCLK (SPDIF_MCLK and not XCORE_MCLK or CODEC_MCLK)?
Is that done due to fan-out considerations?

Thanks
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Ross
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Post by Ross »

Because it is physically very close and therefore a buffer is not required