SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
When the FIFO buffer is enabled for a channel, the user must previously configure in the MCSPI_XFERLEVEL register the AEL and AFL levels and especially the MCSPI_XFERLEVEL[31:16] WCNT bit field to define the number of SPI words to be transferred using the FIFO before enabling the channel.
This counter lets the controller stop the transfer correctly after a defined number of SPI word transfers. If WNCT is set to 0x0000, the counter is not used and the user must stop the transfer manually by disabling the channel; in this case, the user does not know how many SPI transfers have been done. For received words, software must poll the CHxSTAT[5] RXFFE bit and read the MCSPI_RXx receive register to empty the FIFO buffer.
When the end-of-word count interrupt is generated (the MCSPI_IRQSTATUS[17] EOW bit is set), the user can disable the channel and poll the MCSPI_CHxSTAT[5] RXFFE bit to know the last SPI words in the FIFO buffer and read them.
No new request is asserted as long as the system has not performed the correct number of write accesses.