OMAPL138 McBSP FIFO data width

HI,

Let me make sure that, data width of FIFO on McBSP (on L138) is always 32bit, isn't it?

 So I think that, for example when McBSP transfer element size is 8 bit,  data request to DMA will be 32bit, then bus efficiency will be down to 25% ( valid 1 byte, & 3 bytes will discarded) ,  right? And in other words,  data element size should be 32bit when FIFO is enabled?

best regards,

Hirofumi Fujita