This status bit indicates that there is data in the Receive FIFO. It is set whenever there is at least one block of data in the FIFO i.e. for 8-bit mode 8 bits and for 16-bit mode 16 bits. If the RIE[1:0] bits are configured to ‘01’ then whenever this bit gets set an interrupt will be asserted to the processor. This bit is cleared when all valid data has been read out of the FIFO.
Bit 9 = TFNE: Transmit FIFO Not Empty.
This bit is set whenever the FIFO contains at least one data word.