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Enabling Rx0 and Rx1 data lines in TDM16 mode for 32bit (Increased Data Rate Feature)

Category: Software
Product Number: AD2433W

1) We are using Our Own Project Board, in which we are using AD2433 as Main Node.

2) we are using 2 slaves for Downstream A2B Booster Amplifier:

    a) subordinate-1 of 17 Channel audio output and subordinate-2 of 8 channel Audio Output.

    b) Total of 25 Channel Audio output.

3) Initially we had configured TDM Mode as TDM16 and TDM Channel Size as 16 bit and A2B_SLOTFMT for downstream /upstream as 16 bits and DRX0 - 1 pin configuration was used.

4) SFF is 48 kHz

5) This configuration was working fine and all 25 channels, speaker audio output was coming.

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6) As we wanted to improve the audio quality, we moved to 32 Bit configuration

   a) we have configured TDM Mode as TDM16 and TDM Channel Size as 32 bit and A2B_SLOTFMT for downstream/upstream as 32bits and used DRX0/DRX1 - 2 pin configuration was used.

   b) SFF is 48 kHz.

   c) With this Configuration, if we connect only 1 subordinate node of 17 channel A2B Booster Amplifier, we are able to hear audio from all17 Channel's Audio Speaker. (slot0 to slot16 is working)

   d) With this configuration of 1 subordinate in network also, if we use DNMASK register and try to offset the initial slots, and map Amplifier speaker O/p CH1 to slot 4 and CH17 to slot 20, then also from CH1 to CH13 Speaker audio is coming and the rest of the Channels are not giving Audio output.

d) If we connect 2 slaves (17 Ch + 8 CH Amplifier) in the A2b network, then initially both the slaves are discovered, then 2nd subordinate Booster connection get failed or gets disconnected.

So basically, after Slot17 it is not working or looks like clock issue is generated. 

Can we get some feedback for this issue.

Also we tried making subordinate node register - A2B_I2SRATE = 0x05, but this did not work out and the 17-channel audio stopped working.

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7) Also, the I2SGCFG and I2SCFG register setting is controlled by A2B slaves itself

17 Channel A2B Booster:

        A2B_I2SGCFG = 0xE4;

        A2B_I2SCFG = 0x1B; 

  

8 Channel A2B Booster:

        A2B_I2SGCFG = 0xE2;

        A2B_I2SCFG = 0x19; 

Thanks and Regards,

Mandar

  • Hi  

    We suspect something related to your configuration only. We suspect the response cycle value itself might be wrongly configured according to your data slot and cable length requirement. But to confirm is it possible to share your i2c logs with us ? which will make sure what kind of issue is associated with this node drop issue. We would also like to know what INTTYPE you are getting while the node is dropped. 

    If your existing subnode0 itself is not able to produce audio based on the I2S rate register then we guess its the configuration issue at the subnode side. However lets solve the node drop issue first.

    Thanks

    Arun

  • Hi Arun,

      Thanks for the reply.

    I checked the bandwidth usage(once available) using excel sheet - www.analog.com/.../a2b-power-and-bandwidth-calculation-spreadsheet.xlsm

    (a2b-power-and-bandwidth-calculation-spreadsheet)

    After checking the bandwidth, we found that for 25 slots at TDM Mode as TDM32, TDM Channel Size as 32 bits and downstream slot size as 32bits, the bandwidth is exceeding and coming up to 101.7%, so the issue is created.

    so, we decided to make the downstream slot size as 24bits and then the bandwidth decreased and came up to 81.2% and then the issue got resolved.

    Thanks and Regards,

    Mandar