STM32CubeMX (STM32WBA63, TrustZone): Can EXTI11 IRQ target be set to Non-Secure while PA11 remains USART2_RX?

[lgc]

Hello,

I am using STM32CubeMX with an STM32WBA63 project in TrustZone enabled mode, and I have a question about interrupt security attribution.

My use case:

• PA11 is configured as USART2_RX (non-secure application).
• In low power mode, I need wakeup on UART RX activity.
• This relies on EXTI11, so I need EXTI11_IRQn to be targeted to the Non-Secure world (ITNS0 bit 22 = 1).

Issue:

• In CubeMX, I cannot find a way to set EXTI11_IRQn as Non-Secure while PA11 is kept as USART2_RX.
• EXTI11 appears configurable only if I change the pin function to GPIO EXTI, but then USART2 configuration becomes incomplete.

Questions:

1. Is it supported in STM32CubeMX to configure EXTI11_IRQn as Non-Secure when PA11 is assigned to USART2_RX?
2. If yes, where is this setting in the CubeMX UI?
3. If not currently supported, what is the recommended ST approach?
   • Manual USER CODE override in partition configuration?
   • Post-generation patch/script?
   • Any other official best practice?

Current workaround:

• I manually set EXTI11 to Non-Secure in USER CODE in the secure partition configuration, and this works.
• I want to confirm whether there is a native CubeMX way to do it and the recommended maintainable approach.

Tool versions:

• STM32CubeMX: 6.15.0
• STM32CubeWBA package: STM32Cube FW_WBA V1.7.0

Thanks in advance.

[Souhaib MAZHOUD]

Hello ​@lgc 

Thank you for sharing your feedback in ST Community,
STM32CubeMX currently does not support this configuration in the GUI, for this use case, PA11 must remain configured as USART2_RX, It should not be changed to GPIO_EXTI11. I recommend that you manually set EXTI11_IRQn to Non-Secure in the Secure code as you described.

KR, Souhaib