Figure 507. Example Of Suspend Mode Management - ST STM32G4 Series Reference Manual

AES hardware accelerator (AES)
Note: Padding data are swapped in a similar way as normal data, according to the
DATATYPE[1:0] field of the AES_CR register (see
data swapping on page 1477
33.4.7 AES task suspend and resume
A message can be suspended if another message with a higher priority must be processed.
When this highest priority message is sent, the suspended message can resume in both
encryption or decryption mode.
Suspend/resume operations do not break the chaining operation and the message
processing can resume as soon as AES is enabled again to receive the next data block.
Figure 507
order to send a shorter and higher-priority Message 2.
New higher-priority
message 2 to be
processed
A detailed description of suspend/resume operations is in the sections dedicated to each
AES mode.
33.4.8 AES basic chaining modes (ECB, CBC)
Overview
This section gives a brief explanation of the four basic operation modes provided by the
AES computing core: ECB encryption, ECB decryption, CBC encryption and CBC
decryption. For detailed information, refer to the FIPS publication 197 from November 26,
2001.
1456/2083
for details).
gives an example of suspend/resume operation: Message 1 is suspended in

Figure 507. Example of suspend mode management

Message 1
128-bit block 1
128-bit block 2
128-bit block 3
128-bit block 4
128-bit block 5
128-bit block 6
...
RM0440 Rev 1
Section 33.4.13: AES data registers and
AES suspend
sequence
AES resume
sequence
RM0440
Message 2
128-bit block 1
128-bit block 2
MSv42148V1