58.1 Description

The Advanced Encryption Standard Bridge (AESB) provides on-the-fly off-chip memory encryption/decryption compliant with the American FIPS (Federal Information Processing Standard) Publication 197 specification.

The AESB supports three confidentiality modes of operation for symmetrical key block cipher algorithms (ECB, CBC and CTR), as specified in the NIST Special Publication 800-38A Recommendation.

The AESB key is loaded by the software.

The 128-bit AESB key is stored in the AESB Key register made of four 32-bit write-only AESB Key Word registers (AESB_KEYWR0–3).

The 128-bit input data and initialization vector (for some modes) are each stored in four 32-bit registers (AESB_IDATARx and AESB_IVRx) which are all write-only.

As soon as the initialization vector, the input data and the key are configured, the encryption/decryption process may be started. Then the encrypted/decrypted data will be ready to be read out on the four 32-bit output data registers (AESB_ODATARx).