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TLV320AIC3106-Q1: TLV320AIC3106-Q1 Connected To Multiple Audio Devices

Part Number: TLV320AIC3106-Q1

Hello 

  If I plan to design a car audio hands-free device using the TLV320AIC3106-Q1 audio codec,
there will be two I2S audio sources (SOC and BT PCM) feeding into the audio codec. In the specification,
Figure 32. TLV320AIC3106-Q1 Connected To Multiple Audio Devices,

I found a similar application. I would like to inquire if there is a reference circuit design available for us to compare against.
In particular, for the connection between DOUT of Processor 1 and Processor 2, is it directly shorted on the circuit?

Sincerely,
Jerry

  • Hello YuJui,

    We have a typical application schematic in our datasheet (see below).  However, I do not know of a "Reference circuit design" that for this device other than the EVM.

    I hope this helps. 

    Best,
    Andrew

  • Hello Andrew,

    The circuit provided in the Typical Application only replicates the application shown in Figure 32. Was the EVM circuit designed specifically for the application with two processors? I need to know what circuits should be reserved for Processor 1 and Processor 2 on the DOUT.

    In EVM circuit (It's using the 1 processor application , how could I design 2 processor on it ?)


    Sincerely,
    Jerry

  • Hi Jerry, 

    The second processor can be connected to MFP, GPIO1 and GPIO2. These pins can be accessed on the J16 header on the EVM and can be configured (either over I2C or the GUI) to act as secondary pins for DIN, BCLK, WCLK. 

    I hope this helps, let me know if you need clarification on anything.

    Best,
    Andrew

  • Hello Andrew,

    I would like to know which circuits should be reserved for Processor 1 and Processor 2 on the DOUT.
    I understand that Processor 2 connects to the DIN, BCLK, and WCLK pins,
    but I'm unsure how to make the connections when both Processor 1 and Processor 2 are active. (DOUT)

    Best regards,
    Jerry


  • Hello Jerry,

    From my understanding, you are trying to have two processors share the I2S bus. You should be able to connect the DOUT pin (using the same trace) of the CODEC to both processor 1 and 2. With DOUT connected to both processors, each processor will be able to handle the data from the CODEC independently. While data into the CODEC can be multiplexed in the data formats listed in 9.5.5 Digital Audio Data Serial Interface.

    Please let me know if I understood correctly.

    Best,
    Andrew

  • Hello Andrew,

    Thank you for your understanding. You are correct in your interpretation. I am indeed trying to have two processors share the I2S bus, and I would like to inquire whether it is necessary to include additional circuitry, such as diodes or MOSFETs, to prevent interference between Processor 1 and Processor 2 when they both connect to the DOUT pin.

    Best regards,
    Jerry

  • Btw as I know when the Dout (digital output) of an I2S (Integrated Inter-IC Sound) audio codec is simultaneously connected to different processors, several scenarios can occur depending on the design and functionality of these processors:

    1. Race Condition: If multiple processors attempt to access the Dout output of the I2S codec simultaneously, it can lead to a race condition. This can result in unpredictable behavior, such as data corruption or errors. Race conditions are common concurrency programming issues that require proper synchronization and mutual exclusion mechanisms to resolve.

    2. Output Conflict: If multiple processors perform write operations on the Dout output of the I2S codec simultaneously, it can cause conflicts. This may make the output data unpredictable or incorrect. To avoid this problem, it is necessary to ensure that only one processor performs write operations on Dout at a given time.

    3. Incorrect Data Reading: If multiple processors simultaneously perform read operations on the Dout of the I2S codec, it can result in incorrect data reading. This is because simultaneous reading by multiple processors can lead to data interference or the reading of invalid data.



  • Hi Jerry,

    No additional circuitry should be needed to connect DOUT from the CODEC to two separate devices. The drive strength of the CODEC output pins is sufficient to drive both controllers. 

    1. Race Condition: from the CODEC point of view this is not an issue. The data will remain the same if both controllers read the data at the same time. 
    2. Output Conflict: for the I2S protocol, the DOUT is the data output of the CODEC. The controllers should not be driving DOUT at all. Only the CODEC will be driving the DOUT line. Each controller has its own DIN path for this reason.
    3. Incorrect Data Reading: Again, this is not an issue since the output buffer has sufficient drive strength for both controller pins.

    I hope this answers your questions.

    Best,
    Andrew

  • Hello Andrew

    Thank you!!

    Sincerely
    Jerry