SPRUIV7B May 2022 – September 2023 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
The PDMA channel remains idle until data is received from the UDMA-P over the PSIL interface. At this time, the PDMA immediately starts copying packet bytes into the MCAN TX buffer corresponding the PDMA/MCAN channel. The number of bytes copied is smaller of the remaining bytes in the packet, or the value of the 'Y' parameter. Once a TX buffer has been filled, the PDMA transfers ownership of the buffer to MCAN by performing an MCAN register write. The PDMA then waits to regain ownership of the TX buffer by waiting for the corresponding MCAN TX event. At this time, the PDMA continues with refilling the TX buffer for the next packet fragment. On subsequent fills (until the end of packet is reached), the PDMA skips over the 8 byte MCAN header, leaving the original contents from the initial fragment copy in place.