I am planning to use the ADAU1979 in an unorthodox manner. I would like to use asynchronous sources for the serial audio port clocks
(LRCLK, BCLK) and the PLL MCLKIN. Is it possible at all? I can select the sampling frequency freely to be either higher or lower
than the serial port frame frequency. If it is possible, I understand that with different Fs there will be either missing or duplicate samples, but in this application it does not matter. (A longish explanation why I would like to do this, so not written here).
Another question: there is the facility to mute the output in case of PLL out of lock, but I did not find what the muting actually does at the output of the ADC (i.e. possibly just holds the previous value, or maybe has a Nth order interpolation between the values before and after the out of lock incident, or maybe it works on the analog side?).
I do not have the evaluation board that would easily be used for testing, but maybe somebody can try?