SWRU543B January 2019 – June 2025 CC3230S , CC3230SF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
When the FIFO buffer is enabled for a channel, the user configures the MCSPI_XFERLEVEL register, the AEL and AFL levels, and the WCNT bit field to define the number of SPI word to be transferred using the FIFO before enabling the channel.
This counter allows the controller to stop the transfer after a defined number of SPI word transfers. If WCNT is set to 0x0000, the counter is not used and the user must stop the transfer manually by disabling the channel, if the user does not know how many SPI transfers have been done. For a receive transfer, the software polls the corresponding FFE bit field and reads the receive register to empty the FIFO buffer. When the end of word count interrupt is generated, the user can disable the channel and poll on the MCSPI_CHSTAT[FFE] register to see if there is a SPI word in the FIFO buffer, and read the last words.