External interrupts question

[matic]

Posted on August 08, 2016 at 20:22

Hi.

Currently I use PA15 pin as external interrupt. The ISR routine is common for lines 10 through 15 and it is called EXTI15_10_IRQHandler. Now, I would like to have another signal connected to pin PB12, which has same IRQ Handler as PA15, and enable interrupt also for PB12. But I don't want to come into ISR when event on PB12 occurs. I just want to poll for the flag in EXTI->PR register. Interrupt (ISR) should occur only at event on PA15.

Is this possible or should I move one signal to different pin?

Thanks

[Tesla DeLorean]

Posted on August 08, 2016 at 20:36

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I don't know, try experimenting.. Obvious things to try are just looking at the GPIO->IDR, or using a pin on a timer with Input Capture that just time-stamps the event and not interrupt, where it would still latch as a CCx event. If the number of pulses were critical, it could be an External Clock. Sounds like you want it to latch, and review later even if it goes away. Does the EXTI differentiate between a pin change ''event'' and masking an interrupt, like other peripheral?

[matic]

Posted on August 08, 2016 at 23:09Yes, the idea was to latch an event and review it later, even if it goes away before. I don't know if a flag in EXTI->PR register could be raised without triggering interrupt, when pin between numbers 10 - 15 is used and when another pin with one of these numbers is already used as EXT interrupt.From: clive1Posted: Monday, August 08, 2016 8:36 PMSubject: External interrupts question

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I don't know, try experimenting..Obvious things to try are just looking at the GPIO->IDR, or using a pin on a timer with Input Capture that just time-stamps the event and not interrupt, where it would still latch as a CCx event. If the number of pulses were critical, it could be an External Clock.Sounds like you want it to latch, and review later even if it goes away.Does the EXTI differentiate between a pin change ''event'' and masking an interrupt, like other peripheral?

[troy1818]

Posted on August 09, 2016 at 08:43

Hi, I am curious about your dilemma. It would be interesting to know if this is possible.

As another solution, depending on the frequency of the signal on PB12 and the frequency running your MCU, you could make that pin a normal input pin and just try and poll it from time to time.Could you please explain why you do not want to have PB12 as interrupt ?