60.4.3.1.1 If AES_MR.LOD = 0

The DATRDY flag is cleared when at least one AES_ODATARx is read (see the following figure).

Figure 60-1. Manual and Auto Modes with AES_MR.LOD = 0

If the user does not want to read AES_ODATARx between each encryption/decryption, the DATRDY flag will not be cleared. If the DATRDY flag is not cleared, the user cannot know the end of the following encryptions/decryptions.