STM32G474 - DS12288 Rev 4 - What is EVENTOUT in Sections 4.10 and 4.11

[Singh.Harjit]

Section 4.10: on pages 58:73, Table 12, every pin has "EVENTOUT".

Section 4.11: on pages 74:80, Table 13, every row has "EVENTOUT" under AF15.

I found this: https://community.st.com/s/question/0D50X00009Xkc2bSAB/what-is-the-eventout-cortex-output but it doesn't have any information.

Did a web search and came across a reference to a "SEV" instruction and multiprocessing but it doesn't make sense.

[KnarfB]

When a GPIO is configured as EVENTOUT, it can generate a short pulse when a SEV instruction is executed. This is meant for multiprocessor sleep/wakeup synchronization. The Definitive Guide by Joseph Yiu has some more explanations.

[Andrea Canepa]

Also I have always wondered the usefulness of mapping a GPIO as EVENTOUT, but in the documentation of STM32G4 it does not mention it.

I also tried to read the post you are referring to (dating back to 2008/2011 so with references to documents not valid for STM32G4), but I didn't understand how you can use it.

From the documentation of the EXTI peripheral we can understand that a GPIO can be used to generate an event (Input) with the EXTI0 / EXTI15, and this is clear, and I have personally tried it and it works.

But if I look at the description of the EXTI_EMR1 or EMR2 register, I have the possibility to enable some events towards the peripherals (which ones?).

However, if I activate EVENTOUT in more GPIO outputs I should be able to select which event to send to which of the outputs, otherwise both EVENTOUT outputs would have the same signal. What use can it have?

In short, a clarification with reference to our dear STM32G4 would be welcome.

Thanks

Andrea