I have some trouble with my st32cubeMX. I can not enable the EXTI on line 2, why ??

[KHaug.1]

The enable boxed are there, but only for EXTI line 2, it's greyed out.

[waclawek.jan]

Maybe you don't have a free pin with which this interrupt would be associated? Cube has a weird notion of EXTI being an exclusive function of a pin.

I don't use Cube/CubeMX so may be completely wrong.

JW

[ChahinezC · Accepted solution]

Hello @KHaug.1​,

Thank you for your feedback,

Actually this is an expected behavior. When it comes to multicontext MCUs, you need to use "pin reservation" feature for GPIO pins. The interrupt will be available when you assign the used pin for EXTI 2 to CM4.

To do so, right click on the pin then select Pin Reservation and finally check Cortex-M4.

Please find below an example with pin PA2:

 

Regards,

Chahinez.

[KHaug.1]

Thanks for your answer. I have stacking the pin to be both EXTI2 and PB2 GPIO input. I this case I need to unstack before I can reserve the pin for CM4. But now it works, thanks !