STMicroelectronics STM32WLEx Reference Manual page 582

AES hardware accelerator (AES)
Bits 16, 6:5 CHMOD[2:0]: Chaining mode selection
This bitfield selects the AES chaining mode:
000: Electronic codebook (ECB)
001: Cipher-block chaining (CBC)
010: Counter mode (CTR)
011: Galois counter mode (GCM) and Galois message authentication code (GMAC)
100: Counter with CBC-MAC (CCM)
others: Reserved
Attempts to write the bitfield are ignored when the EN bit of the AES_CR register is set before the
write access and it is not cleared by that write access.
Bits 4:3 MODE[1:0]: AES operating mode
This bitfield selects the AES operating mode:
00: Mode 1: encryption
01: Mode 2: key derivation (or key preparation for ECB/CBC decryption)
10: Mode 3: decryption
11: Reserved
Attempts to write the bitfield are ignored when the EN bit of the AES_CR register is set before the
write access and it is not cleared by that write access.
Bits 2:1 DATATYPE[1:0]: Data type selection
This bitfield defines the format of data written in the AES_DINR register or read from the
AES_DOUTR register, through selecting the mode of data swapping:
00: None
01: Half-word (16-bit)
10: Byte (8-bit)
11: Bit
For more details, refer to
Attempts to write the bitfield are ignored when the EN bit of the AES_CR register is set before the
write access and it is not cleared by that write access.
Bit 0 EN: AES enable
This bit enables/disables the AES peripheral:
0: Disable
1: Enable
At any moment, clearing then setting the bit re-initializes the AES peripheral.
This bit is automatically cleared by hardware upon the completion of the key preparation (Mode 2)
and upon the completion of GCM/GMAC/CCM initial phase.
21.7.2 AES status register (AES_SR)
Address offset: 0x04
Reset value: 0x0000 0000
31 30 29 28
Res. Res. Res. Res.
15 14 13 12
Res. Res. Res. Res.
Bits 31:4 Reserved, must be kept at reset value.
582/1306
Section 21.4.13: AES data registers and data
27 26 25 24
Res. Res. Res. Res.
11 10 9 8
Res. Res. Res. Res.
RM0461 Rev 5
23 22 21 20
Res. Res. Res. Res.
7 6 5 4
Res. Res. Res. Res.
RM0461
swapping.
19 18 17
Res. Res. Res. Res.
3 2 1
BUSY WRERR RDERR CCF
r r r
16
0
r