Atmel Evaluation Kit for the SAM4E Series of Flash Microcontrollers ATSAM4E-EK ATSAM4E-EK Data Sheet

Product codes
ATSAM4E-EK
Page of 1506
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
638
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 Channel Buffer Transfer Descriptor for DMA 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 631)
.
Warning: In DMA 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”.
Value
Name
Description
0x0
AES128
AES Key Size is 128 bits
0x1
AES192
AES Key Size is 192 bits
0x2
AES256
AES Key Size is 256 bits
Value
Name
Description
0x0
ECB
ECB: Electronic Code Book mode
0x1
CBC
CBC: Cipher Block Chaining mode
0x2
OFB
OFB: Output Feedback mode
0x3
CFB
CFB: Cipher Feedback mode
0x4
CTR
CTR: Counter mode (16-bit internal counter)
Value
Name
Description
0x0
SIZE_128BIT
128-bit
0x1
SIZE_64BIT
64-bit
0x2
SIZE_32BIT
32-bit
0x3
SIZE_16BIT
16-bit
0x4
SIZE_8BIT
8-bit