I want to interface the TK1 to a Bluetooth module that requires PCM formatted audio data (not I2S formatted). Does the TK1 support PCM format, or do I need to add an external chip to change the format
Certainly. While we at Toradex so far only tested I2S with NXP SGTL5000 codecs (be it on-module or on-carrier) the TK1 audio IP definitely supports PCM as well. The K1 data sheet says the following about this:
4 x I2S interfaces: support I2S, RJM, LJM, PCM, TDM (multi-slot mode), S/PDIF (Sony/Philips Digital Interface)
And the Linux kernel sources reveal e.g. the following which could be integrated on Apalis TK1 as well.