SPRUIV7B May 2022 – September 2023 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
The Host initiates a channel teardown by setting the tdown bit in the UDMA-P channel paired with the PDMA. The UDMA-P communicates the teardown state through the PSI-L data channel, to ensure that the teardown is not seen by the PDMA until all the previous UDMA-P data for the channel has been flushed. At this time, the teardown state is reflected in the PSI-L RT Enable register of the PDMA. Note that a non-synchronized teardown can also be initiated by directly clearing the enable bit in the PSI-L RT Enable register of the PDMA.
Once all data has been flushed from the PDMA to the peripheral, the enable state of the PDMA channel is cleared in the PSI-L RT enable register, but the teardown bit remains high. A teardown completion indication is sent back across the status pins of the PSI-L in the form of a credit response with sccnt=0. Upon completion, no further packet processing occurs until the Host re-configures the channel. If the channel fails to teardown because the peripheral has stopped responding, or if the UDMA-P transmission stops on a data boundary that is not compatible with the static TR configuration, the flush bit in the RT enable register can be set to ensure that all data can be properly flushed from the internal pipe.