957
SAM4CP [DATASHEET]
43051E–ATPL–08/14
KEYSIZE: Key Size
Values which are not listed in the table must be considered as “reserved”.
OPMOD: Operation Mode
Values which are not listed in the table must be considered as “reserved”.
For CBC-MAC operating mode, please set OPMOD to CBC and LOD to 1.
LOD: Last Output Data Mode
0: No effect.
After each end of encryption/decryption, the output data are available either on the output data registers (Manual and Auto
modes) or at the address specified in the Receive Pointer register (AES_RPR) for PDC mode.
In Manual and Auto modes, the DATRDY flag is cleared when at least one of the Output Data registers is read.
1: The DATRDY flag is cleared when at least one of the Input Data Registers is written.
No more Output Data Register reads is necessary between consecutive encryptions/decryptions (see
“Last Output Data Mode”
on page 945
).
Warning:
In PDC mode, reading to the Output Data registers before the last data encryption/decryption process may lead to
unpredictable results.
CFBS: Cipher Feedback Data Size
Values which are not listed in table must be considered as “reserved”.
CKEY: Key
Value
0x0
0x1
0x2
Name
AES128
AES192
AES256
Description
AES Key Size is 128 bits
AES Key Size is 192 bits
AES Key Size is 256 bits
Value
0x0
0x1
0x2
0x3
0x4
0x5
Name
ECB
CBC
OFB
CFB
CTR
GCM
Description
ECB: Electronic Code Book mode
CBC: Cipher Block Chaining mode
OFB: Output Feedback mode
CFB: Cipher Feedback mode
CTR: Counter mode (16-bit internal counter)
GCM: Galois/Counter mode
Value
0x0
0x1
0x2
0x3
0x4
Name
SIZE_128BIT
SIZE_64BIT
SIZE_32BIT
SIZE_16BIT
SIZE_8BIT
Description
128-bit
64-bit
32-bit
16-bit
8-bit
Value
Name
Description
This field must be written with 0xE the first time that AES_MR is programmed. For subsequent
programming of the AES_MR, any value can be written, including that of 0xE.
0xE
PASSWD
Always reads as 0.