ADAU1701MINIZ using I2S/TDM input with ADAU1701 as clock master

I want to connect an EVAL-ADAU7002Z board to my EVAL-ADAU1701MINIZ board.  The ADAU7002 requires BCLK and LRCK to be inputs, so I need the ADAU1701 to drive these signals.  It appears that the J7 header on the MINIZ board is hard wired to MP4 and MP5 pins, and these can only be configured as inputs in the Register Controls GUI.   I see that MP10 and MP11 can be configured as "In Lrclk_out" and "In_Bclk_out" respectively in the Register Controls.  These are wired to LEDs on the board, but I can remove the current limit R's and wire these pins up to the MP4 and MP5 pins at J7.  Will this do the trick to drive BCLK and LRCK to the ADAU7002 while also providing these clocks as inputs to the serial input port?

  • 0
    •  Analog Employees 
    on Jul 6, 2021 6:49 PM

    Hello Robsil,

    Yes, you pretty much have this figured out correctly. You have to externally connect MP10 and MP11 over to MP4 and MP5 to bring the serial output port clocks over to the serial input port. Then if course you need to connect it to the ADAU7002. 

    The resistors for the LEDs are optional. I have left them in and it does not seem to cause issues but if you find it is too much of a load then you remove the resistors. It is kind of handy to see them at partial brightness so you know the clocks are there.

    This is a great part but the serial port clocks do not make much sense. You cannot use the serial input or output ports separately with different clocks. So why are there four pins? The connection should have been done inside the part and only take up two MP pins not four. I was not here when this was designed but it was an oversight. 

    Dave T

  • Thanks for the reply Dave!  I just got back to my bench on this project so I'll give it a try.

  • Hi Dave, I can't seem to get audio to flow into the DSP; I'm seeing what looks like good SDOUT signal coming from the ADAU7002 (the clock hooks worked as expected), but I'm not sure how to access that signal in SigmaStudio.  I'm running in I2S mode, and I have MP[3..0] selected to "Input Sdata_in3..0" in the GPIO register controls under Hardware Configuration.   I've tried finding the signal in my schematic by placing the blocks "IO/Input/Input" (and trying all 10 channels) and also the "IO/GPIO/Input/Interface Read"  but none of these seem to be sourcing the signal from the ADAU7002.  I can check my setup is working by feeding analog audio into the line in jack and picking it up on channels 0 and 1 of the "IO/Input/Input" block.  Am I missing some register settings maybe?   See below for my register setup and schematic.

  • 0
    •  Analog Employees 
    on Jul 22, 2021 8:00 PM in reply to Robsil

    Hello Robsil,

    I think it would be good to get the ADAU7002 out of the equation. I do not know if you can do this with your hardware since I see you are using some GPIO that is on the same pins that you would need to do this experiment. 

    I will attach a project that takes an oscillator in the DSP and sends it out of the serial port. Then you need to jumper this serial port output over to the first serial input of the DSP. SDAT_IN0. Then you will be able to hear it on the line out and see it on the meters. If this works then your config of the serial ports are good. 

    If it does not work then you have to look closer as to why it does not work. Are the clock jumpers going to the correct pins? Etc. 

    Also, it would be good to get some screenshots of the I2S signals on a scope to see if something else might be an issue. 

    MP6 is the pin that will have the SDATA Out 0. You have that as an input. Look at your circuit to see if you can just not use a switch or remove it? Basically, all that is needed with this project is to add one jumper from what you should already have setup. 

    Let me know how it goes. 

    Dave T

    ADAU1701 Digital Out with Digital In Loopback test.zip