Hello,
There might be a confusion in nomenclature here. I2S (inter-IC sound) is an audio interface that transfers data encoded in linear PCM (pulse code modulation) format. So, I2S actually is a kind of PCM.
The ADAU144x devices allow you to set the number of data bits in the word, the number of channels in the frame, and where the MSB (most significant bit) starts in relation to the frame start (delay by 0, 1, or 8). You can also set the frame clock waveform type, and the clock polarity for the frame clock and the bit clock.