An EDMA transfer is always defined in terms of three dimensions. Figure 16-18 shows the three dimensions used by EDMA controller transfers. These three dimensions are defined as:
- 1st Dimension or Array (A): The 1st dimension in a transfer consists of EDMA_TPCC_ABCNT_n[15:0] ACNT contiguous bytes.
- 2nd Dimension or Frame (B): The 2nd dimension in a transfer consists of EDMA_TPCC_ABCNT_n[31:16] BCNT arrays of ACNT bytes. Each array transfer in the 2nd dimension is separated from each other by an index programmed using bit-fields EDMA_TPCC_BIDX_n[15:0] SBIDX or EDMA_TPCC_BIDX_n[31:16] DBIDX.
- 3rd Dimension or Block (C): The 3rd dimension in a transfer consists of CCNT frames of BCNT arrays of ACNT bytes. The Count for 3rd Dimension is defined in register EDMA_TPCC_CCNT_n[15:0] CCNT. Each transfer in the 3rd dimension is separated from the previous by an index programmed using EDMA_TPCC_CIDX_n[15:0] SCIDX or EDMA_TPCC_CIDX_n[31:16] DCIDX.
Note: The reference point for the index depends on the synchronization type. The amount of data transferred upon receipt of a trigger/synchronization event is controlled by the synchronization types (EDMA_TPCC_OPT_n[2] SYNCDIM bit). For these three dimensions, only two synchronization types are supported: A-synchronized transfers and AB-synchronized transfers.