EXTI in STM32MP257F in cubeMX and configuring NVIC.

Amit_RS · ‎2026-03-26

Dear all,
I was trying to setup the NVIC for EXTI for certain pins on STM32MP257F over CubeMX. However the nomenclature in CubeMX confuses me a lot. As I know there are two EXTIs: EXTI1 and EXTI2 which completely changes when we look into NVIC there it shows EXTI and EXTI1. Now the confusion is if EXTI is EXTI1 or 2 and so on.

Thanking you all.

with regards

Amit

PatrickF · ‎2026-03-27

Hi @Amit_RS

Agree CubeMx is not clear enough.

Looking at RM0547 Section "31 Interrupt list" will help you.

Regards.

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Amit_RS · ‎2026-03-27

Hi @PatrickF ,

I looked through the reference manual, however it doesn't mention why assigning GPIOs to EXTI open up two EXTI instances i.e EXTI and EXTI1. Also I couldn't find information on what is the difference between them. If you see my first image there you can clearly see EXTI line 7 interrupt and EXTI1 line 7 interrupt. So it completely confuses me as RM never mentions it.

regards
Amit

PatrickF · ‎2026-03-27

Agreed, it is confusing. I could guess 'EXTI' is EXTI2.
I confirm you could assign a GPIO to either EXTI1 or EXTI2 (or both, but useless).
Maybe looking at generated code could help to clarify.

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Amit_RS · ‎2026-03-27

Yeah looking at generated code could may help. But I don't think if that it could be assigned to both 1 and 2 or it confuses because if it is so why the RIF assigns CID2 to EXTI1 only even if I haven't enabled the NVIC in any of them as in my picture. Please look into line 0, 7, and 8 in my attached pictures of RIF for EXTI 1 and EXTI 2.