SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
There are some differences in the way the EDMA_TPCC logic treats a dummy versus a null transfer request. A null transfer request is an error condition, but a dummy transfer is a legal transfer of 0 bytes. A null transfer causes an error bit (En) in EDMA_TPCC_EMR to get set and the En bit in EDMA_TPCC_SER remains set, essentially preventing any further transfers on that channel without clearing the associated error registers.
Table 16-61 summarizes the conditions and effects of null and dummy transfer requests.
Feature | Null TR | Dummy TR |
---|---|---|
EDMA_TPCC_EMR / EDMA_TPCC_EMRH / EDMA_TPCC_QEMR is set | Yes | No |
EDMA_TPCC_SER / EDMA_TPCC_SERH / EDMA_TPCC_QSER remains set | Yes | No |
Link update (STATIC = 0 in EDMA_TPCC_OPT_n) | Yes | Yes |
EDMA_TPCC_QER is set | Yes | Yes |
EDMA_TPCC_IPR / EDMA_TPCC_IPRH, EDMA_TPCC_CER / EDMA_TPCC_CERH is set using early completion | Yes | Yes |