AN02003 ASRC Aliasing issue, SPDIF receive Topic is solved

[Joe]

The FIR filter coefficients of the ASRC can be adjusted to any values for different characteristics but this isn't a trivial software effort.

You can see the current FIR filter coefficients here for instance:

https://github.com/xmos/lib_src/tree/de ... FilterData

We don't have any canned slow roll off etc options unfortunately.

Cheers,
Joe

[Joe]

In case you haven't seen the documentation, this has some explanations of the filters used etc.

https://github.com/xmos/lib_src/release ... v2.7.0.pdf

[paulvongrundan]

Thank you very much, everyone, for helping with the troubleshooting and for the information.

I think I will put the thread to rest as solved now.

Best regards,
Paul

[infiniteimprobability]

Hi All,
we have updated the develop branch of this app note so it has the lib_board_support fix. This will now run through the release process and should be updated on xmos.com shortly.

We also added pre-attenuate by 1dB and post gain by 1dB so new users don't get caught out by feeding in sharp 0dB FS signals. You can turn it off in the makefile with:

Code: Select all

-DAPPLY_PRE_POST_GAIN=0

There's a note in the docs about Mr. Gibbs' findings.

Here's the changelog:

https://github.com/xmosnotes/an02003/bl ... NGELOG.rst

Thanks for all the feedback on this. It helps awareness and gives us the info we need so we can improve things :)
Ed

[infiniteimprobability]

The updated app note with fixes has made it to the main website now:

https://www.xmos.com/file/an02003-spdif ... -with-asrc