Datasheet

32072H–AVR32–10/2012

AT32UC3A3

• CKEY: Countermeasure Key

Writing the value 0xE to this field allows the CTYPE field to be modified.

Writing another value to this field has no effect.

This bit always reads as zero.

• CFBS: Cipher Feedback Data Size

• LOD: Last Output Data Mode

Writing a one to this bit will enabled the LOD mode.

Writing a zero to this bit will disabled the LOD mode.

These mode is described in the Table 33-3 on page 895.

• OPMOD: Operation Mode

• KEYSIZE: Key Size

CFBS Description

0 128-bit

1 64-bit

2 32-bit

3 16-bit

48-bit

Others Reserved

OPMOD Description

0 ECB: Electronic Code Book mode

1 CBC: Cipher Block Chaining mode

2 OFB: Output Feedback mode

3 CFB: Cipher Feedback mode

4 CTR: Counter mode

Others Reserved

KEYSIZE Description

0 AES Key Size is 128 bits

1 AES Key Size is 192 bits

Others AES Key Size is 256 bits