SPRZ580 December 2024 AM62D-Q1
BCDMA: RX Channel can lockup in certain scenarios
BCDMA RX chan Teardown can lockup channel and cannot be used for subsequent transfers if none of the TRs have EOP flag set in configuration specific flags field. Subsequently when channel is re-enabled, transfer would not complete and will terminate with various errors in TR response.
a) When receiving data from a PSIL/PDMA peripheral, EOP flag needs to be set in the each TR's configuration specific flag field and PDMA's 1 X-Y FIFO Mode Static TR "Z" paramater should be set to non zero value in order for channel teardown to function properly and cleanup the internal state memory. Otherwise it leads to channel lockups on subsequent runs. The PDMA Z count should also match the TR size, so that PDMA delineates each transfer as an individual packet. This is especially problematic in cases like where TRPD has infinite reload count set to perform cyclic transfer using a single set of TRs in streaming mode, in which case each TR could potentially be the last one.
b) If the usecase doesn't allow for PDMA Z count to be set in advance or packet EOP cannot be set then alternate is to use PKTDMA in single buffer mode instead of BCDMA.