SLAU893B October 2023 – July 2024 MSPM0C1103 , MSPM0C1103-Q1 , MSPM0C1104 , MSPM0C1104-Q1
The SPI provides an interface to the DMA controller with separate channels for transmit and receive. The DMA operation of the SPI is enabled through the SPI Event and DMA register. When DMA operation is enabled, the SPI asserts a DMA request on the receive or transmit channel when the associated FIFO can transfer data.
For the receive channel a transfer request is asserted whenever the amount of data in the receive FIFO is at or above the FIFO trigger level configured using the RXIFLSEL bit in IFLS register or the receive timeout has triggered, in this case the amount of data received so far will be transmitted.
For the transmit channel a transfer request is asserted whenever the transmit FIFO contains fewer characters than the FIFO trigger level configured using the TXIFLSEL bit in IFLS register. The DMA transfer requests are handled automatically by the DMA controller depending on how the DMA channel is configured.
The DMA transfers can be configured and aligned between the data width of the SPI transfers and the bus accesses width of 8/16 bits to make an efficient usage of the bus. The trigger and transfers are independent for receive and transmit.
See more information about the interrupt and event in Section 12.2.6.2 section.