SPRUIV7B May 2022 – September 2023 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
This flow describes the host sequence for a transfer of any type defined in Section 12.2.3.5.2.1.8, Transfer Procedures With FIFO.
In multi-channel, only one channel can use the FIFO.
Before enabling the FIFO for a channel (MCSPI_CHCONF_0/1/2/3[28] FFER and MCSPI_CHCONF_0/1/2/3[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 Peripheral mode, the channel 0 only can be activated. The correct SPIEN line is chosen in MCSPI_CHCONF_0[22-21] SPIENSLV bits.
The MCSPI module can start the transfer only when the first write request has been released by writing the MCSPI_TX_0/1/2/3 register, even in receive-only mode (only one write request occurs in this case).