SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The master receive mode prevents the MPU from refilling the MCSPI_TXx register (minimizing data movement) when only reception is meaningful.
The master receive mode is programmable per channel (the MCSPI_CHxCONF[13:12] TRM bit field).
The master receive-only mode enables channel scheduling only on the empty state of the MCSPI_RXx register.
Rule 1 and Rule 3, defined in Section 24.4.4.3.2, apply in this mode.
Rule 2, defined in Section 24.4.4.3.2, does not apply.
In the master receive-only mode, software must write dummy data to the MCSPI_TXx register. Only one dummy write is enough to receive any number of words from the slave. Software must ensure that the MCSPI_TXx register is always full (the TXx_EMPTY bits of MCSPI_IRQSTATUS) when receiving. The content of the MCSPI_TXx register is always loaded into the shift register when the shift register is assigned. After writing the dummy data to the MCSPI_TXx register, the TXx_EMPTY and TXx_UNDERFLOW bits in the MCSPI_IRQSTATUS register are never set in receive-only mode.
The MCSPI_CHxSTAT[2] EOT bit gives the status of serialization. The RXx_FULL bits of the MCSPI_IRQSTATUS register are set when received data is loaded from the shift register to the corresponding MCSPI_RXx register. The MCSPI_IRQSTATUS[3] RX0_OVERFLOW bit is never set in this mode.