47.7.8.5 Single Data Mode
In Single Data mode, only one data is written every time MCSPI_TDR is accessed, and only one data is read every time MCSPI_RDR is accessed.
When MCSPI_FMR.TXRDYM = 0, the Transmit FIFO operates in Single Data mode.
When MCSPI_FMR.RXRDYM = 0, the Receive FIFO operates in Single Data mode.
If Host mode is used (MCSPI_MR.MSTR=1), the Receive FIFO must operate in Single Data mode.
If Variable Peripheral Select mode is used (MCSPI_MR.PS=1), the Transmit FIFO must operate in Single Data mode.
