SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The slave receive mode is programmable (set the MCSPI_CHxCONF[13:12] TRM bit field [where x = 0] to 0x0).
In slave transmit-and-receive mode, the MCSPI_TXx register must be loaded before McSPI is selected by an external SPI master device.
After a channel is enabled, transmission and reception proceed with interrupt and DMA request events.
The MCSPI_TXx register content is always loaded in the shift register whether it is updated or not. The event TXx_UNDERFLOW is activated accordingly and does not prevent transmission.
When the SPI word transfer completes (the MCSPI_CHxSTAT0[2] EOT bit [where x = 0] is set to 1), the received data is transferred to the channel receive register.
To use McSPI as a slave transmit-only device, the RXx_FULL and RX0_OVERFLOW interrupts and DMA read requests must be disabled due to the state of the MCSPI_RXx register (see Section 26.4.4.7.2, Interrupt Events in Slave Mode).