SLAU847D October 2022 – May 2024 MSPM0L1105 , MSPM0L1106 , MSPM0L1227 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2228 , MSPM0L2228-Q1
Each DMA channel is independently configured for its trigger source with DMATSEL. The DMATSEL bits should be modified only when the DMACTLx.DMAEN bit is 0; otherwise, unpredictable DMA triggers can occur.
See the device-specific data sheet for the list of triggers available, along with their respective DMATSEL values.
When selecting the trigger, the trigger must not have already occurred, or the transfer does not take place.
DMA channels can be internally triggered upon the completion of activity on another channel to support cascading. Completion of activity occurs when a DMA channel’s DMASZ counter reaches zero. This is beneficial for applications where data can be retrieved, transferred, and/or error-checked without an interrupt or event configuration.
Set the DMATINT bit to internally trigger the next DMA channel based on the DMATSEL trigger source. Once the DMATSEL trigger occurs, the next DMA channel begins to automatically execute.
For example, if UART data is received and transmitted to SRAM through DMA channel 0 and DMATSEL is set to UART RX, then DMA channel 1 can be internally triggered when the UART is finished receiving data. If DMA channel 1 is configured to transmit the data from SRAM to CRC, then the DMA transfer will trigger once the UART data is received. In this case, the DMA channels are cascaded from Channel 0 to Channel 1.