Data Sheet

302
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
19.8.1.4 CRC Checksum
The CRCCHKSUM represents the 16- or 32-bit checksum value and the generated CRC.
Name: CRCCHKSUM
Offset: 0x08
Reset: 0x00000000
Property: Enable-Protected, Write-Protected
z 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.
These bits should only be read when CRC Module Busy bit in the CRC Status register (CRCSTATUS.BUSY) is
zero.
If CRC-16 is selected and CRCSTATUS.BUSY is zero (CRC generation is completed), this bit group will contain a
valid checksum.
If CRC-32 is selected and CRCSTATUS.BUSY is zero (CRC generation is completed), this bit group will contain a
valid reversed checksum. Bit 31 is swapped with bit 0, bit 30 with bit 1, etc.
Bit 3130292827262524
CRCCHKSUM[31:24]
AccessR/WR/WR/WR/WR/WR/WR/WR/W
Reset00000000
Bit 2322212019181716
CRCCHKSUM[23:16]
AccessR/WR/WR/WR/WR/WR/WR/WR/W
Reset00000000
Bit 151413121110 9 8
CRCCHKSUM[15:8]
AccessR/WR/WR/WR/WR/WR/WR/WR/W
Reset00000000
Bit 76543210
CRCCHKSUM[7:0]
AccessR/WR/WR/WR/WR/WR/WR/WR/W
Reset00000000