25.7.8.5 Append Mode

The DMA provides a CRC append mode, CHCTRLCRCk.CRCAPP, which appends the CRC or Checksum value to the end of a block transfer.

When CRCAPP=0, the DMA reads the data from the source, passes through the CRC module and writes the data to the destination. The calculated CRC or checksum is left in the CRCDAT register at the end of the block transfer.

Setting CRCAPP=1 enables the append mode. The DMA performs the same function as described for CRCAPP=0. However, at the end of the block transfer the DMA appends the CHCRCDATk.CRCDATA content to the destination by writing up to 4 bytes of data depending on the CRCMD setting. The BYTORDER and WBOEN settings do not affect the CRC value being written to the destination. Only the CHCTRLCRCk.CRCXOR and CHCTRLCRCk.CRCROUT register affect how the CHCRCDATk.CRCDATA value is written out.