54.5.10 AES Initialization Vector Register x
This register can only be written if the WPEN bit is cleared in the AES Write Protection Mode Register.
The four 32-bit Initialization Vector registers set the 128-bit Initialization Vector data block that is used by some modes of operation as an additional initial input.
AES_IVR0 corresponds to the first word of the Initialization Vector, AES_IVR3 to the last one.
These registers are write-only to prevent the Initialization Vector from being read by another application.
For CBC, OFB and CFB modes, the IV input value corresponds to the initialization vector.
For CTR mode, the IV input value corresponds to the initial counter value.
These registers are not used in ECB mode and must not be written.
When switching from an operating mode requiring the initialization vectors (e.g. CBC, GCM) to another operating mode that does not require initialization vectors (e.g. ECB) and a message of one block has been processed, AES_IVRx must be cleared before switching to the new mode
| Name: | AES_IVRx |
| Offset: | 0x60 + x*0x04 [x=0..3] |
| Reset: | – |
| Property: | Write-only |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| IV[31:24] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| IV[23:16] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| IV[15:8] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| IV[7:0] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |