38.8.2. Control B
Name:
CTRLB
Offset:
0x04
Reset:
0x00
Property:
PAC Write-Protection
Bit
7
6
5
4
3
2
1
0
GFMUL
EOM
NEWMSG
START
Access
R/W
R/W
R/W
R/W
Reset
0
0
0
0
Bit 3 – GFMUL: GF Multiplication
This bit is applicable only to GCM mode.
Value
Description
0
No action
1
Setting this bit calculates GF multiplication with data buffer content and hashkey register
content.
Bit 2 – EOM: End of Message
This bit is applicable only to GCM mode.
Value
Description
0
No action
1
Setting this bit generates final GHASH value for the message.
Bit 1 – NEWMSG: New Message
This bit is used in cipher block chaining (CBC), cipher feedback (CFB) and output feedback (OFB),
counter (CTR) modes to indicate the hardware to use Initialization vector for encrypting the first block of
message.
Value
Description
0
No action
1
Setting this bit indicates start of new message to the module.
Bit 0 – START: Start Encryption/Decryption
Value
Description
0
No action
1
Start encryption / decryption in manual mode.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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