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Syous.1
Syous.1
Associate
July 29, 2020
Question

What "EXTI" stands for ?

  • July 29, 2020
  • 7 replies
  • 4775 views

Hi All

About EXTI :

In some stm reference manual about "EXTI" i read some strange things :

 For example:

In STM32f070 Ref. manual "EXTI" stands for " Extended Interrupt/event Controller".

In STM32f407 Ref. manual "EXTI" stands for " External Interrupt/event Controller".

I want to know which is correct? bcs of this controller issues with external and internal interrupts/events, I personally thinks that Extended will be more meaningfull.

Is'nt this a mistake on manuals?

This topic has been closed for replies.

7 replies

S.Ma
S.Ma
Principal
July 29, 2020

It's external interrupt, it can generate interrupt or HW events based on incoming signal rise and/or falling edge on some GPIO pins.

It seems specs are not built to be consistent.

TDK
TDK
July 29, 2020

For the F0 it means extended. For the F4 it means external. I don't think there's really a conflict with calling them different things in different manuals. It's just a name. As long as the manuals are self-consistent.

Edit: They are also different peripherals. In the F4, it only handles external events. In the F0 (and H7), it handles external and internal events, so "external" would be misleading. Makes sense to me.

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S.Ma
S.Ma
Principal
July 30, 2020

so there is room for another ip change with Enhanced interrupt event, evolved interrupt event, etc...

waclawek.jan
waclawek.jan
Super User
July 30, 2020

> In the F4, it only handles external events.

In F4, EXTI has 23 inputs - 16 are from pins, the rest are internal signals.

This is the same in ALL STM32s. The reason is, that EXTI handles the wake-up mechanism from the low-power modes.

As others said, it's just a name, which nobody actually uses (only the acronym is actually used), so it does not really matter.

JW

Syous.1
Syous.1Author
Associate
July 31, 2020

> it's just a name,

As a matter of fact if just naming varies, It's a poor naming that can make people confusing.

I think must be a rational reasons for these different naming on various series or it should be corrected to use consistent naming in all series.

Thanks alot,

    TDK
    TDK
    July 30, 2020

    Yeah, I guess you're right. Looking at register, F0/F4/F7 are almost identical. H7 is another beast, but similar.

    Seems the manuals aren't consistent either, at least not the F7 manual:

    0693W000003Bg4YQAS.png

    But agreed, it hardly matters.

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    Piranha
    Piranha
    Principal III
    August 1, 2020

    Also take a note that "external" in this context means external relative to CPU core, not the whole MCU.

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