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TAD5242EVM-K: No sound in TDM mode.

Kotaro Hagura
Prodigy 20 points
Part Number: TAD5242EVM-K

Tool/software:

USB audio is not working well, no sound.
User's guide says "The default settings for the USB audio interface are 32-bit frame size, 48-kHz sampling rate, BCLK and FSYNC ratio is 256, and the format is
timedivision multiplexing (TDM)" . I confirmed the clock & data which was made by AC-MB were input to the IC, and confirmed the IC hardware properly configurations.
What is causing the problem?

For more infomation about above case, no sound when short to Ground with 4.7KOhm for target TDM  mode, a sound comes out from only in Out1 channel when Short to Ground for target I2S mode, a sound comes out from only in Out2 channel when Short to AVDD with 22KOhm for  target LJ mode.
I tested this with 1kHz Sine wave.

  • 0
    TI__Mastermind 30711 points

    Since this is a HW controlled device, there is no registers to make sure it is set correctly. Only the S0 and S1 on the AC-MB board to select USB which it seems you already set it.

    The next thing is to set the data format that we are sending in. This is done by the 4.7KOhm resistor to GND or direct short to GND.

     You selected Short to Ground with 4.7KOhm : Target   (SLAVE) TDM , so the device expect to receive the clks and you further indicated that ratio of BCLK to fs so you are providing the clks as expected by device. The only thing that is left to confirm is the format of the data  coming to the DAC.

    Using the following equation and above data, since you have a 32bit with x256, it means you have an 8ch input. 

    BCK= # of CH* Ch depth * Fsync, 

    MD4-MD5 Setting also sets SE or Diff or ...( go through all the jumpers setting) 

    So please confirm that the input data has the correct format as shown in  Figure 6-3. TDM Mode Protocol Timing (MD0 shorted to ground with 4.7K Ohms) in Target Mode.

    Please monitor FSYN, DIN and BCLK on the scope and make sure your input matches with Figure 6.3. You can also check the same thing in I2S mode and verify your input is of correct format as you expect.

    Regards,

    Arash