13.14.6.3.1.3 Adding a Descriptor Between Existing Descriptors
To insert a new descriptor 'C' between two existing descriptors ('A' and 'B'), the descriptor currently executed by the DMA must be identified.
- If DMA is executing descriptor B, descriptor C cannot be inserted.
- If DMA has not started to execute descriptor A, follow the steps:
- If DMA is executing descriptor A:
- Apply the software suspend command to the channel and
- Perform steps 2.1 through 2.4.
- Apply the software resume command to the channel.