Yeah, the SA1100 has no I2S on it, so the I2S is actually generated by an SPI port, with some external logic to make the word select. If it glitches at all, word select resyncs so the first worked after a falling CS is left (or right... whichever, it's always the same one). That, and the display interfacing to CLCD using every 4th pixel and a PIC was thought of on the train to and from London

The HW is locked at 44,100 too.

This may impede you finding any audio drivers for it, simply because the SA1100 didn't really have I2S audio in the first place (I think it had PCM?)

If you just rebuffer your audio output it into 4608 byte chunks you should be just fine, however.

The "DSP" does no decode at all. It's a car audio DSP designed to be used with a CD and/or tape mechanism. It does EQ and FM stereo processing, balance, loudness boost, dynamic range compression type of thing. It is fed the vanilla I2S by the SA1100.