Texas Instruments CC2650DK ユーザーズマニュアル
AES Cryptoprocessor Overview
10.1.4.4.1 Algorithm Select
This algorithm-selection register configures the internal destination of the DMA controller.
10.1.4.4.1.1 Algorithm Select
summarizes the allowed bit combinations of the [ALGSEL] register.
Table 10-3. Valid Combinations for ALGSEL Flags
Flags
Operation
KEY STORE
AES
TAG
Key store is loaded through the DMA
1
0
0
AES data is loaded through the DMA and
encrypted/decrypted data are read through the
DMA (encryption/decryption) or AES data is
encrypted/decrypted data are read through the
DMA (encryption/decryption) or AES data is
0
1
0
loaded through the DMA and result tag is read
through the slave interface (authentication-only
operations)
through the slave interface (authentication-only
operations)
AES data is loaded through the DMA, result tag
is read through the DMA (authentication-only
is read through the DMA (authentication-only
0
1
1
operations)
10.1.4.4.2 Master PROT Enable
10.1.4.4.2.1 Master PROT-Privileged Access-Enable
The [DMAPORTCTL] register selects the AHB transfer protection control for DMA transfers, using the key
store as destination.
store as destination.
10.1.4.4.3 Software Reset
Refer to
, Soft Reset, for more details on the soft reset procedure.
To perform a software reset of the AES module, write a 1 to the RESET bit in the SWRESET register.
When the software reset completes, the RESET bit in the SWRESET register is automatically reset.
Software must ensure that the software reset completes before starting any operations.
When the software reset completes, the RESET bit in the SWRESET register is automatically reset.
Software must ensure that the software reset completes before starting any operations.
In the DMA Control module, software reset is used to reset the DMAC to stop all transfers and clear the
[DMAPORTERR] register. After the software reset is performed, all channels are disabled and no new
requests are performed by the channels. The DMAC waits for the existing (active) requests to finish, then
sets the DMAC status registers.
[DMAPORTERR] register. After the software reset is performed, all channels are disabled and no new
requests are performed by the channels. The DMAC waits for the existing (active) requests to finish, then
sets the DMAC status registers.
10.1.4.5 AES Engine
The composition of the AES core is the following:
•
The main data path operates on the input block, performing the required substitution, shift, and mix
operations.
operations.
•
The key scheduler generates the round keys. A new subkey is generated and XORed with the data
each round.
each round.
The AES key scheduler generates the round keys. During each round, a new subkey is generated from
the input key to be XORed with the data. Round keys are generated on-the-fly and parallel to data
processing to minimize register requirements. For encryption operations, the key sequencer transfers the
initial key data to the AES core. For decryption operations, the key scheduler must provide the final
subkey to the AES core so it can generate the subkeys in reverse order.
the input key to be XORed with the data. Round keys are generated on-the-fly and parallel to data
processing to minimize register requirements. For encryption operations, the key sequencer transfers the
initial key data to the AES core. For decryption operations, the key scheduler must provide the final
subkey to the AES core so it can generate the subkeys in reverse order.
The AES core operates on the input block and performs the required substitution, shift, and mix
operations. For each round, the encryption core receives the proper round key from the AES key
scheduler. A fundamental component of the AES algorithm is the S-Box. The S-Box provides a unique
8-bit output for each 8-bit input.
operations. For each round, the encryption core receives the proper round key from the AES key
scheduler. A fundamental component of the AES algorithm is the S-Box. The S-Box provides a unique
8-bit output for each 8-bit input.
805
SWCU117A – February 2015 – Revised March 2015
Cryptography
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