USB audio reference design DOP to Native DSD

Sub forums for various specialist XMOS applications. e.g. USB audio, motor control and robotics.
JanWW
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Joined: Mon Jan 25, 2016 3:39 pm

Post by JanWW »

I think the XMOS output is still configured as PCM, which defines do I have to set to get the DSD output configured?

Should I disable this define?:
#define I2S_CHANS_DAC (2)

And enable this one?
#define DSD_CHANS_DAC (2)

I do have defined them both right now in order to get it compiling. I only just have one (stereo) output to the DAC.

I'm not able to get it compiling when disabling the I2S_Chans_DAC define...

JW


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infiniteimprobability
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Post by infiniteimprobability »

I'm not able to get it compiling when disabling the I2S_Chans_DAC define...
This is expected - DSD support is an addition to PCM output. There is no valid configuration for DSD only. All of the core transport relies on there being a valid output path, which is enabled by setting I2S_Chans_DAC to greater than 0.

If there was a valid configuration for DSD only, it would be DSD native only because DoP of course requires PCM to be supported (because of the "oP" bit).

I have to confess I'm not 100% sure what your goal is here. Could you clarify?
JanWW
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Joined: Mon Jan 25, 2016 3:39 pm

Post by JanWW »

Thanks for your answer, that makes sense.

I was able to get it working! Had to adapt/add some divide code because I was using a 1024*44100=45.15MHz masterclock.

Another question, I would like to generate a lrclk in dsdmode, I know it's not needed in dsd mode, but my spdif transmitter needs a lrclk. Can you help me further?

***
else if(dsdMode == DSD_MODE_DOP)
{
p_lrclk <: 0xFF00FF00;// try to generate another (lr)clk in dsd mode, doesn't work, seems to stop the audio stream
if(!everyOther)
**
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Ross
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Post by Ross »

Please use a new topic for a new question. Thanks.
amninder
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Post by amninder »

Hi JanWW,

Out of curiosity, Are you testing the DOP128 and DOP256 on Windows PC?
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