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ADAU1966A I2S Multiplexing

dears:

        I have a special need now .

        I need to make a multi-channel audio product .

        I want to know how many analog audio channels can I output if I input one channel  I2S to adau1966a. (for example ,DSDATA1 input)

        Because I want to get multichannel audio, but I don't know what to do now,

        (1)  The first way is to turn all the I2S into multi-channel, but I don't know how to do it. 

        (2)  The second  Looking for a DAC with single I2S and multiple analog audio 

        I want to be able to control the on-off operation of each path independently.

        Could the experts of ADI please give me a good proposal?   I would appreciate it if you could help me.

thanks!

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  • Hello terryyuan,

    I will first define my terminology,

    I2S is a somewhat standard serial format where two channels of audio is sent over one SDATA line during one sample period. 

    TDM, (Time Domain Multiplexed) is a format where multiple channels of data can be sent over one SDATA line during one sample period.

    TDM not as standard in its details as I2S but our parts are flexible enough to handle most variations. Generally, you append "TDM" with the number of channels it has per sample period. So TDM8 has eight channels and TDM16 has sixteen channels etc.

    The ADAU1966A has eight SDATA inputs. So you can send to it eight I2S signals to be able to send out 16 channels of audio with two channels per SDATA input.

    If you use TDM4 then you only need to use the first four SDATA inputs to reach all 16 DAC outputs.

    If you use TDM8 then you only needs DSDATA1 and DSDATA2 pins to get signal to all 16 outputs. (Note that in this part we use DSDATA instead of SDATA, it means the same thing.

    If you use TDM16 then all 16 DAC output signals will be taken off of DSDATA1. All the other DSDATA pins will do nothing.

    The register settings need to be set to properly route the data from the DSDATAx pins to the correct DACs. 

    There are individual volume and mote registers for each channel of the DAC. So you can mute any channel by changing a setting in a register. 

    What the part cannot do is route data from one channel to another channel internally. It only takes the data from the DSATA pin it is assigned to and no others. So it is not possible to take one channel of audio and send it out of all 16 channels. This part is intended to be connected to a DSP and the DSP will have to send the audio to each channel. 

    One thing you can do is externally route the same I2S signal to all eight DSDATA pins and then the same two audio channels will be sent out on the eight stereo pairs of DACs. We do this on the evaluation board where you can take the SPDIF input if the evaluation board and send that signal to all eight inputs of the DAC. We use a buffer to do it. You can see this detailed in the user guide where there is a schematic in the guide. 

    So are you using a DSP? 

    How many channels do you want to send to how many outputs? Is it one channel or two channels of input to go to 16 channels of DAC output?

    Dave T

  • Hi Dave:

          Thank you very much.

          I am using ADAU1452. the adau 1452 only one channel I2S input. and output two channel I2S.and then i wanna get 18 channel analog music.

          And then i must route the same I2S signal to all eight DSDATA pins.

         And then I  can get so much analog audio.because i do not konw whether the TDM  is suitable for music transmission, because it is generally used in voice applications, such as multi array mic.Even if I use TDM, I should also need to change one I2S into multiple TDM in DSP.

         Can one channel I2S generate multiple TDM(TDM4\8\16) in adau1452 ?

          Now, i wanna get 16 channel analog audio from adau1966A. so i need route the one channel i2s becoming eight channel i2s.

          i send the two picture of this ,is the dsp i2s output connection to all dsdata directly?

    Thanks!

         

Reply
  • Hi Dave:

          Thank you very much.

          I am using ADAU1452. the adau 1452 only one channel I2S input. and output two channel I2S.and then i wanna get 18 channel analog music.

          And then i must route the same I2S signal to all eight DSDATA pins.

         And then I  can get so much analog audio.because i do not konw whether the TDM  is suitable for music transmission, because it is generally used in voice applications, such as multi array mic.Even if I use TDM, I should also need to change one I2S into multiple TDM in DSP.

         Can one channel I2S generate multiple TDM(TDM4\8\16) in adau1452 ?

          Now, i wanna get 16 channel analog audio from adau1966A. so i need route the one channel i2s becoming eight channel i2s.

          i send the two picture of this ,is the dsp i2s output connection to all dsdata directly?

    Thanks!

         

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