SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
This flow describes the host sequence for a transfer of any type defined in Section 26.4.5.2.1.8, Transfer Procedures With FIFO.
In multi-channel, only one channel can use the FIFO.
Before enabling the FIFO for a channel (MCSPI_CHxCONF[28] FFER and MCSPI_CHxCONF[27] FFEW bits), the host must check that the FIFO is not enabled for another channel, even if these channels are not used.
In transmit-and-receive mode, the FIFO can be enabled for write or read request only, without FIFO for the other request.
In Slave mode, the channel 0 only can be activated. The correct SPIEN line is chosen in MCSPI_CHxCONF[22:21] SPIENSLV bits (where x = 0).
The McSPI module can start the transfer only when the first write request has been released by writing the MCSPI_TXx register, even in receive-only mode (only one write request occurs in this case).