DSP_D_DSP_A digital PurePath loopback design fails to work.

LostElectron

Prodigy 180 points

I am trying to run a simple digital loopback in a 3254 codec using DSP_D_DSP_A component in a real design using PPS.

The i2s is multiplexed over 3x3254 devices using i2s mode.

I have already discarded bad 3254 clk configuration as this configuration (clks) works fine in some other tests.

Device0 provides clocks setup for device1 and 2.

PPS design below: nothing magic very simple design:

When I observ with a scope the DIN my design it works exactly as expected (din enters slot1 very cleanly). At dout I have a definitive flat line.

I was expecting the input to be replicated to dout. What's wrong here ? I have tried synchronous mode with no help.

I have been reading this forum thread "PurePath digital-digital model for digital interface loopback" but this does not help me.

Any idea where the prblem could be ?

Thanks for the help.

over 8 years ago

0 LostElectron over 8 years ago

Prodigy 180 points

Working!
I am not really sure how useful are the preprocessor directives in the PPS framework setup but I have may be too drastic in removing some..
For example as I am using a uniq sample rate I removed all those "if" directives and let just appear the internal regs setup...

; %%if (%%prop(SampleRate) == 8000) -- removed
reg[ 0][ 5] = 0x61 ; not used P=6, R=1, J=12
reg[ 0][ 6] = 0x0c ; not used P=6, R=1, J=12

OK Solved anyway.

0 Diego Melendez over 8 years ago in reply to LostElectron

TI__Guru 57800 points

Hi Lost Electron,

Thanks for the feedback, we are glad you have solved your issue.

Regards,

-Diego Meléndez López
Audio Applications Engineer

Audio

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DSP_D_DSP_A digital PurePath loopback design fails to work.