When reading the SAI receiver FIFO, how can one tell whether the sample read is left or right channel? Surely this is written somewhere but I have not found it.
It looks as though the mask register (RMR) can prevent one of the channels from not being stored into the FIFO. Is that right? I presume that 0x0001 would cause left to be ignored, and 0x0002 would cause right to be ignored?
One thing that I find missing from the SAI documentation, is the definition of frame. I assume a frame is one left and one right sample for I2S. Is that right?
Is I2S always stereo? I can't see how it would work otherwise as it requires a pulse on the LRCLK to know what's what. But nowhere have a I found the definitive statement, not even in the Phillips spec.