Datasheet
13.4.1.2 Initialization Subsequence
The following sections list the initialization subsequences for the available encryption/decryption
modes:
Subsequence: Initialize CCM AES Core Mode
The CCM mode initialization is as follows:
1. Define the width of the length field and the length of the authentication field by programming
the CCM_L and CCM_M bit fields in the AES_CTRL register at offset 0x050.
2. Enable counter mode by setting the CTR bit in the AES_CTRL register.
3. Load the authentication data length in the AUTH field of the AES Authentication Data Length
(AES_AUTH_LENGTH) register at offset 0x05C.
4. Select the IV counter by programming the CTR_WIDTH field in the AES_CTRL register.
5. Load the AES Initialization Vector Input n (AES_IV_IN_n) registers at offset 0x040 to 0x04C.
Subsequence: Initialize GCM AES Core Mode
The following steps to enable GCM mode is as follows:
1. Enable counter mode by setting the CTR bit in the AES_CTRL register.
2. Load the authentication data length in the AUTH field of the AES Authentication Data Length
(AES_AUTH_LENGTH) register at offset 0x05C.
3. Select the IV counter by programming the CTR_WIDTH field in the AES_CTRL register.
4. Load the AES Initialization Vector Input n (AES_IV_IN_n) registers at offset 0x040 to 0x04C.
Subsequence: Initialize CBC-MAC AES Core Mode
To initialize CBC-MAC Mode:
1. Enable CBC-MAC Mode by setting the CBCMAC bit in the AES_CTRL register.
2. Select encryption mode by setting the DIRECTION bit in the AES_CTRL register at offset 0x050
3. Load the AES Initialization Vector Input n (AES_IV_IN_n) registers at offset 0x040 to 0x04C.
Subsequence: Initialize F9 AES Core Mode
The steps for configuring the AES for F9 mode is as follows:
1. Enable F9 Mode by setting the F9 bit in the AES_CTRL register.
2. Set the key size to 128 bits by programming the KEY_SIZE field to 0x1 in the AES_CTRL
register.
3. Load the AES Initialization Vector Input n (AES_IV_IN_n) registers at offset 0x040 to 0x04C.
Subsequence: Initialize F8 AES Core Mode
The steps for configuring the AES for F8 mode is as follows:
June 18, 2014980
Texas Instruments-Production Data
Advance Encryption Standard Accelerator (AES)