STMicroelectronics STM32WL5 Series Reference Manual page 686

AES hardware accelerator (AES)
Bit 3 BUSY: Busy
This flag indicates whether AES is idle or busy during GCM payload encryption phase:
0: Idle
1: Busy
When the flag indicates "idle", the current GCM encryption processing may be suspended to
process a higher-priority message. In other chaining modes, or in GCM phases other than payload
encryption, the flag must be ignored for the suspend process.
Bit 2 WRERR: Write error
This flag indicates the detection of an unexpected write operation to the AES_DINR register (during
computation or data output phase):
0: Not detected
1: Detected
The flag is set by hardware. It is cleared by software upon setting the ERRC bit of the AES_CR
register.
Upon the flag setting, an interrupt is generated if enabled through the ERRIE bit of the AES_CR
register.
The flag setting has no impact on the AES operation. Unexpected write is ignored.
Bit 1 RDERR: Read error flag
This flag indicates the detection of an unexpected read operation from the AES_DOUTR register
(during computation or data input phase):
0: Not detected
1: Detected
The flag is set by hardware. It is cleared by software upon setting the ERRC bit of the AES_CR
register.
Upon the flag setting, an interrupt is generated if enabled through the ERRIE bit of the AES_CR
register.
The flag setting has no impact on the AES operation. Unexpected read returns zero.
Bit 0 CCF: Computation completed flag
This flag indicates whether the computation is completed:
0: Not completed
1: Completed
The flag is set by hardware upon the completion of the computation. It is cleared by software, upon
setting the CCFC bit of the AES_CR register.
Upon the flag setting, an interrupt is generated if enabled through the CCFIE bit of the AES_CR
register.
The flag is significant only when the DMAOUTEN bit is 0. It may stay high when DMA_EN is 1.
686/1450 RM0453 Rev 5
RM0453