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ADAU1446 ASRC

Question asked by bill on May 13, 2013
Latest reply on Jul 19, 2013 by bill

I have two digital audio devices that will not be synchronized to each other and that I want to exchange digital audio back and forth between. Into and out of each device there are 4 lines of I2S TDM4 serial audio (16x16). Each device will be the master clock generator on their own separate boards. I'm thinking I can pull this off using 2 ADAU1446's? I'm not 100% familiar with ASRC's but it looks like this is the way to go. The DSP's can be synchronized to  the devices in anyway that allows for this to work. If I understand the spec. sheet correctly the flow would be as follows.

1) The 4 input TDM4 lines are sent to through the Automatic Input Channel Assignment section and assigned to 16 of the total 24 individual input channels.

2)Then based off of registers setting  the FARM  inputs each channel pair into the 8x2 ASRC block

3) I can make the Output Rate selection pairs synchronize to one LRCLK/BLCK clock pair from the receiving device?

4) Each serial output selection pair will come directly from the ASRC

5) Again my register settings will setup the Automatic Output Channel Assignments to put the output pairs back into TDM4 format

 

All of this above will be repeated with another ADAU1446 but the audio will be headed in the opposite direction.

 

If any of  what I typed above is correct my questions are:

1) If the audio comes directly into and out of the ASRC's block will the audio be available to the DSP core for Sigma Studio manipulation?

2) What tells the ASRC what pins contain the rate of the input audio?

 

Attached is what I think would be the schematic for this setup and I also sketched by hand a overall connection diagram.

Your help with this would be much appreciated.

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