Atmel Evaluation Kit for the SAM4E Series of Flash Microcontrollers ATSAM4E-EK ATSAM4E-EK Data Sheet
Product codes
ATSAM4E-EK
637
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
31.6.2 AES Mode Register
Name: AES_MR
Address:
0x40004004
Access: Read/Write
CIPHER: Processing Mode
0: Decrypts data.
1: Encrypts data.
DUALBUFF: Dual Input Buffer
PROCDLY: Processing Delay
Processing Time = N
× (PROCDLY + 1)
where
N = 10 when KEYSIZE = 0
N = 12 when KEYSIZE = 1
N = 14 when KEYSIZE = 2
The Processing Time represents the number of clock cycles that the AES needs in order to perform one
encryption/decryption.
encryption/decryption.
Note: The best performance is achieved with PROCDLY equal to 0.
SMOD: Start Mode
Values which are not listed in the table must be considered as “reserved”.
If a DMA transfer is used, 0x2 must be configured. Refer to
for more details.
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
CKEY
–
CFBS
15
14
13
12
11
10
9
8
LOD
OPMOD
KEYSIZE
SMOD
7
6
5
4
3
2
1
0
PROCDLY
DUALBUFF
–
–
CIPHER
Value
Name
Description
0x0
INACTIVE
AES_IDATARx cannot be written during processing of previous block.
0x1
ACTIVE
AES_IDATARx can be written during processing of previous block when SMOD = 0x2. It speeds
up the overall runtime of large files.
up the overall runtime of large files.
Value
Name
Description
0x0
MANUAL_STAR
T
T
Manual Mode
0x1
AUTO_START
Auto Mode
0x2
IDATAR0_START
AES_IDATAR0 access only Auto Mode