SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
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 MCSPI 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 MCSPI 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 MCSPI transfers have been done. For received words, software must poll the MCSPI_CHSTAT_i[5] RXFFE bit and read the MCSPI_RX_0/1/2/3 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_CHSTAT_0/1/2/3[5] RXFFE bit to know the last MCSPI 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.