There are multiple ways to initiate a programmed data transfer using the EDMA_TPCC channel controller. Transfers on DMA channels are initiated by three sources.
They are listed as follows:
- Event-triggered transfer request (this is the typical usage of EDMA controller): A peripheral, system, or externally-generated event triggers a transfer request.
- Manually-triggered transfer request:The CPU manually triggers a transfer by writing a 1 to the corresponding bit in the event set registers (EDMA_TPCC_ESR / EDMA_TPCC_ESRH).
- Chain-triggered transfer request: A transfer is triggered on the completion of another transfer or sub-transfer.
Transfers on QDMA channels are initiated by two sources. They are as follows:
- Auto-triggered transfer request: Writing to the programmed trigger word triggers a transfer.
- Link-triggered transfer requests: Writing to the trigger word triggers the transfer when linking occurs.