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Could not find the answer to How many times same interrupt can be in pending state at a time? (In ARM CM-3) e.g. :
We are processing one interrupt INT_RX, at the same time 3 more packets received. so I expect 3 times more this interrupt to appear sequentially. Will it be notified 3 times or once or none?
Only one interrupt can be pending.Any further interrupt is lost. Depending on the peripheral, it might be possible to check there.
42bs's answer is correct, but I'd like to add that you should clear your pending bit as one of the first things you do in your interrupt.
If you clear it as the last thing, the next interrupt of the same type could perhaps go pending while the pending bit is still not cleared, thus an interrupt would be lost.
Such things usually happen only if the interrupts can happen frequently; eg. it would not happen for a timer-interrupt, which occurs once per hour for instance (because you normally won't stay in an interrupt for more than a few nanoseconds or microseconds).
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