58.4.5.2 If AESB_MR.LOD = 1

AESB_ISR.DATRDY is cleared when at least one Input Data register is written, so before the start of a new transfer (see the figure below). No more Output Data register reads are necessary between consecutive encryptions/decryptions.

Figure 58-2. Manual and Auto Modes with AESB_MR.LOD = 1