RM0376 Datasheet, PDF (411/968 Pages) STMicroelectronics – This reference manual targets application developers

RM0376
Advanced encryption standard hardware accelerator (AES)
18.12.3
AES data input register (AES_DINR)
Address offset: 0x08
Reset value: 0x0000 0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
DINR[31:16]
rw
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
rw
rw
rw
7
6
5
rw
rw
rw
4
3
2
rw
rw
1
0
DINR[15:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 31:0 DINR[31:0]: Data Input Register.
This register must be written 4 times during the input phase:
– In Mode 1 (Encryption), 4 words must be written which represent the plain text from MSB to LSB.
– In Mode 2 (Key Derivation), This register is not used because this mode concerns only derivative
key calculation starting from the AES_KEYRx register.
– In Mode 3 (Decryption) and 4 (Key Derivation+Decryption), 4 words must be written which represent
the cipher text MSB to LSB.
Note: This register must be accessed with 32-bit data width.
18.12.4
AES data output register (AES_DOUTR)
Address offset: 0x0C
Reset value: 0x0000 0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
DOUTR[31:16]
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DOUTR[15:0]
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
Bits 31:0 DOUTR[31:0]: Data output register
This register is read only.
Once the CCF flag (Computation Complete Flag) is set, reading this data register 4 times gives
access to the 128-bit output results:
- In Mode 1 (Encryption), the 4 words read represent the cipher text from MSB to LSB.
- In Mode 2 (Key Derivation), there is no need to read this register because the derivative key is
located in the AES_KEYRx registers.
- In Mode 3 (Decryption) and Mode 4 (Key Derivation+Decryption), the 4 words read represent the
plain text from MSB to LSB.
Note: This register must be accessed with 32-bit data width.
DocID025941 Rev 2
411/968
416