SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Packet reception is accomplished within the PDMA by moving data from structures that are located in memory accessible via the VBUSP Memory Interface(s) onto the receive PSI-L interface. On the Rx side of the PDMA, these transfers are always reads. Data is read from an attached memory mapped space and packed into the Rx per-channel buffer for that channel. At a later time, the data is moved from the Rx per-channel FIFO to a remote peer DMA entity via the Rx PSI-L interface.
The sequences of logical transactions that are performed by the PDMA on the memory interface during receive is dependent on the channel type. The following sections describe what will happen for the two different channel types.