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Original question:

TAS6422EQ1EVM: Optical Input don't work

DIR9001-Q1: DIR9001-Q1 transmiting problem on my TAS6422E-Q1 EVM

dorian novelli
Prodigy 40 points
Part Number: DIR9001-Q1
Other Parts Discussed in Thread: DIR9001

Hi everyone,

As you can see in this thread : https://e2e.ti.com/support/audio-group/audio/f/audio-forum/1185148/tas6422eq1evm-optical-input-don-t-work/4480972#4480972 , I'm currently looking for why I can't use my optical INPUT on my TAS6422E-QI EVM.

Obviously, I have a problem with my SDIN1 signal when I swith in optical input. The SDIN1 signal in USB input (it's working) doesn't look the same at all that the SDIN1 signal in optical input.

The DIR9001 have to turn into wave the optical input signal and this is not the case.

Can you help my to test the DIR9001 and to know why it don't work correctly ?

Thank you very much,

Dorian

  • 0
    TI__Mastermind 27470 points

    Hi,

    Out SPDIF expert is out of office until wednesday, please be patient as his responses are delayed.

  • 0
    TI__Mastermind 30991 points

    Hi Dorin,

    Just to be clear on your question: If  you are  using TAS6422 with optical  or non-optical input from a different source directly  and it is working fine , but  fails when you use DIR9001 and provide the optical signal from DIR9001 into TAS6422 EVM, then you need to probe the signals coming out of DIR9001 and see what is different from your expectation. 

    My guess is your output format from DIR device  is not matching the requirement for your TAS EVM. Please note  the description form datasheet : "DIR9001 supports MSB-first PCM data output in 24-bit I2S, 24-bit left justified, 24-bit right justified, or 16-bit right justified form. Sampling rates of 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, and 96 kHz are supported on the serial audio data output when in PLL mode. All functions which the DIR9001 provides can be controlled directly through control pins. This means that they can be pulled high or low for full operation of the DIR9001 without a microcontroller. "  Also there are some basic requirements for inputs going to DIR device that you can read about it in page 12 of DS.

    You have to go through your set up ( for example output format  from DIR  is matching the input format needed  for TAS) and make sure it is set up correctly. 

    So basically you need to do the following:

    1- Get the TAS6422 EVM to work correctly without DIR first.

    2- Plot all the clks and data waveforms for this case

    3- Now set up the DIR to generate the same format at its output , no need to connect TAS to it yet. Just need to get it set up according your target waveforms.

    4- Once your output format from DIR is what you expect then connect it ( send it to) TAS6422 EVM and it should work fine.

    I am closing this thread for now but feel free to reply if you have any additional question.

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 40 points

    Hello arash,

    I understand what you are saying and what you advise me has been done in the previous topic: e2e.ti.com/.../tas6422eq1evm-optical- input-don-t-work/4480972#4480972
    The output of the DIR does not match the output of the Xmos input to the TAS. Knowing that the output of the xmos works and the TAS emits sound. So I don't understand what else to test, there are all the curves in the topic above.

    Good for you,

  • 0 in reply to dorian novelli
    TI__Mastermind 30991 points

    Hello Dorian, I understand you got the TAS EVM to work fine, now you have to make sure your DIR is outputting the exact format and clks. For example does it need LJ or RJ or I2S?  what is the fs and BCK and ... that you need? So  you need to set up the DIR to generate that specific output. I listed few tables that you should check and set up according to your target clks needed for TAS EVM, for example 

    Table 2. Operation Mode and Clock Source ,  

    Table 3. SCKO, BCKO, and LRCKO Frequencies Set by PSCK[1:0]

    Table 7. Serial Audio Data Output Format Set by FMT[1:0]

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 40 points

    Hi,

    Sorry, I don't understand what I need to do.

    I need to program the DIR ?

    It's not programmed before tas6422evm sending ?

    What's the table 2-3-7 ?

    I just want to use the TAS6422EVM with the optical input, that's all.

    Regards,

  • 0 in reply to dorian novelli
    TI__Mastermind 30991 points

    Hi Dorian, 

    Usually when you are using a DIR or any other supporting IC on an EVM, you should not need to program them;  somehow I thought you wanted  to use a dedicated DIR EVM and attached to  TAS6422 EVM for debugging. So all the instruction that I gave above  was for this scenario which is not your case.  You should be able to connect the optical cable and use your TAS6422EVM .

    I would also send the optical data using a different source such as AP (audio precision) so you can set and see the values of clocks putting  in. In AP we have to specify the data is from optical source.

    I also assume you made sure there is no switch or jumper that needs to be set on your EVM , when switching to OPTICAL mode .

    You can do a sanity check and see when  you connect the optical cable, do you get the I2S signals on the board right before  and after the DIR ( if you think the DIR on the board is the issue- I doubt it myself).  If the DIR is really the issue , I don't think there is a way on their EVM to program the DIR.

    Please check the above and meanwhile l'll  talk to TAS6422's  group in person and will see what I can find out for you. 

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    TI__Mastermind 30991 points

    Dorian, I talked to couple of people from TAS6422 group and they both agreed the EVM should not need any programing on DIT or any other IC on the EVM. 

    Suggestion is to follow the TAS6422EVM user's guide and if still you have any issue with the EVM please reopen the original thread and ask for Gregg to take a look at it.

    Regards.

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 40 points

    Hi,

    Thank you for your investigation. This therefore validates that the problem does not come from the DIR. I will continue my research with Gregg.

Thanks Arash!
  • 0 in reply to dorian novelli
    TI__Mastermind 30991 points

    Thanks Dorian,

    I am closing this ticket now.