Datasheet

20.8.4 CRC Checksum
Name: CRCCHKSUM
Offset: 0x08
Reset: 0x00000000
Property: PAC Write-Protection, Enable-Protected
The CRCCHKSUM represents the 16- or 32-bit checksum value and the generated CRC. The register is
reset to zero by default, but it is possible to reset all bits to one by writing the CRCCHKSUM register
directly. It is possible to write this register only when the CRC module is disabled. If CRC-32 is selected
and the CRC Status Busy flag is cleared (i.e., CRC generation is completed or aborted), the bit reversed
(bit 31 is swapped with bit 0, bit 30 with bit 1, etc.) and complemented result will be read from
CRCCHKSUM. If CRC-16 is selected or the CRC Status Busy flag is set (i.e., CRC generation is
ongoing), CRCCHKSUM will contain the actual content.
Bit 31 30 29 28 27 26 25 24
CRCCHKSUM[31:24]
Access
R/W R/W R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0 0 0
Bit 23 22 21 20 19 18 17 16
CRCCHKSUM[23:16]
Access
R/W R/W R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0 0 0
Bit 15 14 13 12 11 10 9 8
CRCCHKSUM[15:8]
Access
R/W R/W R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0 0 0
Bit 7 6 5 4 3 2 1 0
CRCCHKSUM[7:0]
Access
R/W R/W R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0 0 0
Bits 31:0 – CRCCHKSUM[31:0] CRC Checksum
These bits store the generated CRC result. The 16 MSB bits are always read zero when CRC-16 is
enabled.
SAM D21 Family
DMAC – Direct Memory Access Controller
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 332