54.4.3.1.2 If AES_MR.LOD = 1

This mode is optimized to process AES CBC-MAC operating mode.

The DATRDY flag is cleared when at least one AES_IDATAR is written (see the following figure). No additional AES_ODATAR reads are necessary between consecutive encryptions/decryptions.

Figure 54-2. Manual and Auto Modes with AES_MR.LOD = 1