SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The master transmit-only mode prevents the microprocessor unit (MPU) from reading the MCSPI_RXx register (minimizing data movement) when only transmission is meaningful.
The master transmit-only mode is programmable per channel (the MCSPI_CHxCONF[13:12] TRM bit field). Transmission starts only after data is loaded into the MCSPI_TXx register.
Rule 1 and Rule 2, defined in Section 26.4.4.3.2, apply in this mode.
Rule 3, defined in Section 26.4.4.3.2, does not apply.
In master transmit-only mode, the MCSPI_RXx register state FULL does not prevent transmission and the MCSPI_RXx register is always overwritten with the new SPI word. This event is not significant when only transmission is meaningful. Thus, the RX0_OVERFLOW bit in the MCSPI_IRQSTATUS register is never set in this mode.
The hardware automatically disables the RX_FULL interrupt and the DMA read requests.
The transfer status is given by the MCSPI_CHxSTAT[2] EOT bit.