ADAU1702 - TDM mode configuration.

Hi,

I'm having difficulties configuring the TDM mode on my ADAU1702, and I'm running out of ideas. I am trying to configure the TDM in to send 2 samples to the 4 DACs and despite my best efforts it's still not working.

- I tried routing the input block of sigmaDSP to the dac (as attached), but with the ADAU1702, the input bock only show analog input (As opposed to the ADAU1701 where the input offers 2 analog input and 8 serial in) and that configuration doesn't seem to make sense in regards of the documentation that states that in TDM mode, slots 0 to to 3 are the first half of the audio frame and slots 4 to 7 are the second half.

- My master is sending a 2 samples over 4 channels every 20us or so (attached), with a pulse as LRCLK delauyed by one BCLK.

If some could let me know what I'm missing here that would be greatly appreciated.

Thank you,

Fabien.

Parents
  • +1
    •  Analog Employees 
    on Dec 10, 2018 10:36 PM

    Hello Fabien,

    You do not have the multifunction pins set to be the serial port. So the serial port is getting nothing.

    Try these settings.

    Also, SigmaStudio offers an excellent window into what is going on in the DSP. Use it.

    Do something like this. Then you can see the level and which channels are active.

    The part you quoted about the slots is an older format that everyone has moved away from now but this part was designed a long time ago. What initially was done with TDM is put all the left channels when the clock was low and right channels when the clock was high. In this part when you are in TDM mode I think it sends slot 1 to input 1. But you will see it if you meter all the inputs.

    Dave T

Reply
  • +1
    •  Analog Employees 
    on Dec 10, 2018 10:36 PM

    Hello Fabien,

    You do not have the multifunction pins set to be the serial port. So the serial port is getting nothing.

    Try these settings.

    Also, SigmaStudio offers an excellent window into what is going on in the DSP. Use it.

    Do something like this. Then you can see the level and which channels are active.

    The part you quoted about the slots is an older format that everyone has moved away from now but this part was designed a long time ago. What initially was done with TDM is put all the left channels when the clock was low and right channels when the clock was high. In this part when you are in TDM mode I think it sends slot 1 to input 1. But you will see it if you meter all the inputs.

    Dave T

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