38.8.2 Control B

Name: CTRLB
Offset: 0x04
Reset: 0x00
Property: PAC Write-Protection

Bit 76543210 
     GFMULEOMNEWMSGSTART 
Access R/WR/WR/WR/W 
Reset 0000 

Bit 3 – GFMUL GF Multiplication

This bit is applicable only to GCM mode.
ValueDescription
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.
ValueDescription
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.
ValueDescription
0 No action
1 Setting this bit indicates start of new message to the module.

Bit 0 – START Start Encryption/Decryption

ValueDescription
0 No action
1 Start encryption / decryption in manual mode.