I would like to be able to encode additional user data in an audio stream transmitted from an ADAU1445 and be able to extract that at a head unit using a ADAU1702 (or possibly a ADAU1761). In this way the audio channel wiring can be used to pass commands down the line to a small processor at the head unit (connected via I2C or SPI). The user data or commands would come from the ADAU1445 host processor via SPI.
Is it possible?
I will be using TDM8 16bit and would allocate one 16-bit value as data and commands to the small micro. This could be used to update uP parameters/commands so that it could reprogram the ADAU1702 or update config.
i.e., can the SigmaDSP allow reading or writing of the user data via the SPI port (or should I use a micro with a I2S port and then route via that).