SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The EDMA_TPCC event queue includes watermarking/threshold logic that allows to keep track of maximum usage of all event queues. This is useful for debugging real-time deadline violations that may result from head-of-line blocking on a given EDMA event queue.
The maximum number of events are programed that the queue up in an event queue by programming the threshold value (between 0 to 15) in the queue watermark threshold A register EDMA_TPCC_QWMTHRA. The maximum queue usage is recorded actively in the watermark EDMA_TPCC_QSTATN_i[20:16] WM field of the queue status register, that keeps getting updated based on a comparison of number of valid entries, which is also visible in the EDMA_TPCC_QSTATN_i[12:8] NUMVAL bit and the maximum number of entries.
If the queue usage is exceeded, this status is visible in the EDMA_TPCC registers: the QTHRXCDn bits in the channel controller error register EDMA_TPCC_CCERR[7:0] and the EDMA_TPCC_QSTATN_i[24] THRXCD bit, where n stands for the event queue number. Any bits that are set in EDMA_TPCC_CCERR also generate an EDMA_TPCC error interrupt.