How to Generate the Clock for EXTI ?

[Anthony Lauly]

Posted on July 06, 2018 at 16:09

Sorry for my stupid question, but this makes me really confused. I was just looking for the the bus with connected with the EXTI, then I found that APB2 bus is connected as it is shown in the reference manual in here : 

https://www.st.com/content/ccc/resource/technical/document/reference_manual/4d/ed/bc/89/b5/70/40/dc/DM00135183.pdf/files/DM00135183.pdf/jcr:content/translations/en.DM00135183.pdf

 

so here I attach the screenshot of the datasheet 

But when I tried to activate the clock for APB2 bus in APB2ENR, I cannot find in what bit is the EXTI in.

Then I got confused in what bus and what bit is it to activate the clock for exti. Sorry for this stupid question, by the way I am a new learner

#stm-mcu #datasheet-inconsistency #stm32-interrupt

[waclawek.jan · Accepted solution]

Posted on July 06, 2018 at 16:41

EXTI clock is always enabled.

JW

[Anthony Lauly]

Posted on July 07, 2018 at 05:50

So I dont have to enable it with APB2ENR ?

[waclawek.jan]

Posted on July 08, 2018 at 00:56

No.

[Anthony Lauly]

Posted on July 08, 2018 at 05:57

Thank you sir

[bgaurav1718]

How can I know whether the peripheral needs to have a clock enabled or not? Where exactly in Reference Manual/Datasheet should I look for this info?

[Uwe Bonnes]

A RCC_AHB2ENR_EXTIEN would be a strong sign that explicit enable is needed. absence of that bit is a stong sign that no explicit  enable is needed. And to my knowledge no other STM32 needs explicit EXTI enable.

[Tesla DeLorean]

On the F1 isn't it part of the AFIO ? Been an age, but definitely a couple of things under the AFIO, perhaps SYSCFG/DBGMCU type stuff, would have to look at RM0008 again.