BF70x DMA PSIZE behaviour


what happens when I have configured the SLEN of a SPORT in receive mode to 32 bit but use a DMA to transfer rx'ed data to memory with PSIZE of 16 bit?

Will that copy just 16 bit from the receive data register and if so: the low or high portion?

I want to interface a chip needing 32 colcks and FS but delivering only 16 meaningful bits. Thus, the 16 MSB shifted in could be discarded right away.