31.3.10.4 Auto Repeat Usage Model

When the Auto Repeat bit selects repeat mode (CRCCTRL.AUTOR=1), the CRC operation only sets INTFLAG.CRCDONE at the end of a loop if there is a comparison error. The error causes the logic to set both INTFLAG.CRCDONE and INTFLAG.CRCERR. To restart the CRC, simply clear CRCCTRL.CRCEN, then INTFLAG.CRCDONE and INTFLAG.CRCERR before setting CRCCTRL.CRCEN again.

If there is no comparison error the logic restarts the CRC operation by loading the initial value into ACC, the MLEN into the length counter, and Period into the Period counter. CRCDONE, CRCERR, and CRCEN remain unchanged. As mentioned above, each read waits the Period count including the first read of a loop. The CRC operation continues looping until it detects an error or is stopped manually.