This behavior is correct.

E.g. some times it was needed, that an interrupt must be disabled. But if an trigger event occur during these time, the interrupt pending flag was still set and if the interrupt was enabled again, it can be served.

Also its possible to enable never the interrupt and poll only the interrupt pending flag to see, that an event was happen.

In other cases, if former events should not be served, the interrupt pending flag (e.g. IE0) must be cleared immediately before the interrupt enable flag (e.g. EX0) was set.


Peter