ST X-CUBE-SBSFU STM32Cube Integration Manual page 42

Adapting the user application
As explained in the user manual UM2262, some additional constraints are depending on the
STM32 series:
•
STM32F4 Series, STM32F7 Series, and STM32L1 Series: MPU-based Secure Engine
isolation relies fully on the fact that a privileged level of software execution is required
to access the Secure Engine services. The user application must take this constraint
into account and trust any piece of code running in privileged mode.
•
STM32G0 Series, STM32G4 Series, and STM32H7 Series: when secured, any access
to securable memory area (Fetch, read, programming, erase) is rejected, generating a
bus error. As a consequence, there are no Secure Engine runtime services available
for the user application.
Note: IWDG is started during SBSFU execution. It must be refreshed periodically.
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