SPRUJF8 May 2026 TMS320F28P551SG
Figure 22-4 shows the full block (128 bits) CFB mode of operation for encryption and decryption. The input for the cryptographic core is the IV; the result is XORed with the data. The result is fed back through the IV register as the next input for the cryptographic core. The decryption operation is reversed, but the cryptographic core still performs encryption.
Figure 30-8 AES - CFB Feedback Mode