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Original question:

TLV320AIC3263: TLV320AIC3263

TLV320AIC3263: Capturing 4 microphones mono inputs simultaneously on TLV320AIC3263

user5937803
Prodigy 10 points
Part Number: TLV320AIC3263
Other Parts Discussed in Thread: PCM1840, TAA3040, TLV320AIC34

Tool/software:

Hello,

I am using the TLV320AIC3263 codec and I have 4 separate AUX (line-level) mono inputs. My goal is to capture all 4 channels simultaneously in digital format.

I would like to clarify the following points:

  1. Is it correct that the codec can capture all 4 channels simultaneously using TDM or multi-slot PCM mode?

  2. Will capturing all 4 channels simultaneously introduce any noticeable latency or buffer timing issues?

  3. If yes, what are the critical considerations for slot mapping in codec registers and host-side (i.MX8 / ALSA/ASoC) configuration?

  4. When using PurePath Studio, do I need to add any DSP blocks to capture these 4 channels as raw inputs, or is configuring TDM slots + host enough?

My objective is to capture 4 line-level mono signals as separate channels and later process them into individual WAV files. Any advice or example register/DT configuration would be very helpful.

Thank you.

  • +1
    TI__Genius 14185 points

    Hi,

    The AIC3263 has two ADCs, so it can only process 2 separate streams of data into digital signal. We can sum some channels, like 2 channels on each ADC, but of course that will include two microphone signals on one digital channel. To get 4 separate channels of TDM, I would recommend to get another stereo ADC to add two more input channels to your ASI, or to check out other options with four channels. This would include the TAA3040, PCM3140, or PCM1840. Or, if you are looking for a codec, I would recommend the TLV320AIC34 which is very similar to two AIC3104 codecs in one chip. 

    Let me know what you think.

    Best,
    Mir

  • 0 in reply to Mir Jeffres
    Prodigy 10 points

    Hi thank you for reply,

    I’m new to this and studying the TLV320AIC3263 datasheet. I’m particularly looking at the Multiple Channel Operation, Single Data Lines (ASI1) section.


    TLV320AIC3263 Application Reference Guide page 117/289

    I have a few questions:

    • Are the “channels” in ASI1 simply digital slots for sending data to DSP or other devices, or can they be directly mapped to physical inputs?

    • My goal is to capture 4 separate microphone inputs as independent digital channels with the hardware I have. Can I use these ASI1 slots for that, or are they only meant for audio coming from ASI1/ASI2 sources like DSP or other digital audio?

    • If it’s possible, what should I consider to route analog microphones to these slots? Are ADC routing and offset settings enough?

    In short, can ASI1 multi-channel slots be used to map physical microphone inputs separately with the hardware I have, or are they just for digital data transport?

    I’m looking to understand the correct approach and any practical solutions I can implement.

    Thanks!

  • 0 in reply to user5937803
    TI__Genius 14185 points

    Hi,

    The ASI channels are slots for sending data, and you can configure which channels/slots the physical inputs on the chip are present on. This would be useful for a system with multiple chips but one multi-channel audio bus, where all DOUT lines would be connected, each chip could have its own channels it transmits for the MCU to analyze all at once. By default it should transmit on the first 2 channels/slots. You configure which analog inputs make it to the ADCs with register writes, and then the ADC converts those analog signals to digital signals which should be transmitted on slot 0 for L ADC, and slot 1 for R ADC.

    Since the device only has two ADCs, there are two total slots that it can transmit on. These slots are the digital audio samples being transmitted with I2S or TDM protocol (TDM is also called DSP). TDM supports more than 2 channels with the way that the clocks are set up, as we can see in your screenshot. This means we can alter which slots the on-board ADCs are transmitting to, and if combined with other chips transmitting on different slots, then you can fill more channels than you have on the chip itself.

    I would recommend you download these example scripts for this device: https://www.ti.com/tool/download/SLAC598 here you can see in example 6.1, a stereo ADC example register configuration. This is using I2S mode, so there are only 2 channels. But, you can change to TDM/DSP mode with page 4 register 1, same register that sets it to I2S mode. Then, the following registers include the BCLK offset which you can use to set the slot.

    Best,
    Mir

  • 0 in reply to Mir Jeffres
    Prodigy 10 points

    Hi Mir again,

    We are now considering using the PCM6140QRGERQ1 codec instead of TLV320AIC3263. According to the documentation, it has 4 ADCs and supports 4 analog microphone inputs simultaneously. Since our application does not require audio playback, only the ADC functionality is needed.

    My question: Is this understanding correct, and would this codec be suitable for our use case (recording 4 independent mono microphone channels at the same time)?
    Is there any limitation or caveat that I might be missing?

    Thanks in advance!

  • 0 in reply to user5937803
    TI__Genius 14185 points

    Hi,

    Yes, the PCM6140 should work for your 4 microphone channels! You can find an example script to set up 4 channels of recording in the datasheet, in section 9.2.1.2.1. Let me know if you need a schematic review or more help with it. It may be best to open a new thread with the other device for ease of tracking in the future.

    Best,
    Mir