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ADAU1452 Sigma Studio Input Block TDM slot/channel mapping

SigmaDSP & SigmaStudio GKE Feb 9, 2023 00:00 2 replies Original on forum ↗
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GKE Question
Feb 9, 2023 00:00

Hello,

I have trawled the help files and this forum looking for a definitive answer to the question about TDM slot input mapping channels to the Sigma Studio input block.

The help file suggests that it's about register settings but offers slot 0 & 1 being Left & Right ADC, then inputs 2-9 being TDM slots 1,5,2,6,3,7,4,8 respectively.

I am using a Cirrus CS42448 CODEC in TDM mode where there are 6 ADC inputs 1 - 6 mapped directly into TDM slots 1 to 6 then the two AUX ADC channels mapped into TDM slots 7 & 8.

Data format is 24-bit left justified in the 32-bit time slot.

So in Sigma Studio I have the CODEC output mapping to the ADAU1452 SDATA_IN0 which is in TDM Mode 8 channels 32/bit per channel and 24 bit word length. My config uses a 16-channel Input Block.

The strange thing is that when I trace the audio signals from the CODEC ADC inputs to the Sigma Studio Input block, I get input block channels 0 and 1 receiving TDM slots 5 & 6. Input block 4 & 5 are TDM slots 1 & 2 and Input Block 6 & 7 are receiving DM slots 3 & 4.

I understand that the TDM slot mapping assignments are often different for different CODECs, but there is no logic to what I am seeing - unless I haven't found the correct document explaining this in the datasheet?

TIA

GKE

Audio Signal Processors

adau1452

software

SigmaDSP Audio Processors

Sigma Studio 4.7-1831

pbthesp Reply
Feb 9, 2023 00:00

It appears you are half a TDM frame out, try changing the polarity of the Word clock/ LR signal.

GKE Reply
Feb 9, 2023 00:00

Brilliant - thanks for that. Exactly the problem. I had the LR Clock set to negative polarity. Swap to positive and everything is where it should be.