How to output  multiple I2S signal through ADAU1442 SPDIF out?

The S/PDIF transmitter on the ADAU1442 only supports two audio channels, so you would need to mix down your multiple I2S sources inside the DSP into two audio channels. Is that OK for your application?

If the HDMI receiver and SigmaDSP are synchronous to each other, you can simply route the I2S data from the HDMI receiver to the SigmaDSP and have the SigmaDSP act as a slave on the clock port. If the HDMI receiver and SigmaDSP are not synchronous (which is the more likely scenario), you'll need to route the data from the I2S inputs to the SigmaDSP's ASRCs (Asynchronous Sample Rate Converters) and then send them to the DSP to be mixed and output on the S/PDIF transmitter.

This is all accomplished using the register control GUI in SigmaStudio and then programming a basic signal flow that would take the ASRC inputs, mix them down to 2 channels, and then output to the S/PDIF transmitter.

We can provide more help if you can provide some more details about your system.

Hi Brett,

Thank a lot for your quick answer, I already routed the I2S data from HDMI receiver to the SigmaDSP acting as a slave and it works fine.

It is a perfect solution for our application.

Best regards,

Yamil Garcia.