GPIO interupts

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by IanB on Mon Feb 09 08:06:05 MST 2015
Could I have some clarification how the GPIO interrupts work on the LPC11E37.

I have 8 interrupts - PINTSEL determines which pin activates which interrupt.

Then for each interrupt I have PIN INTERRUPT MODE register (PMODE) which determines if each interrupt is level or edge sensitive.

Then I have a "Pin interrupt level (rising edge) interrupt enable register", a "Pin interrupt active level (falling edge) interrupt enable register", a "Pin interrupt rising edge register", a "Pin interrupt falling edge register" and finally a "Pin interrupt status register".

The manual says that the bits in the interrupt enable registers enable the interrupt (which makes sense), but do I also have to have bits set in the ISEL register before the interrupt will actually work?

If I didn't want interrupts, but just wanted to poll in software to find whether there had been a rising edge or not, presumably I would look in the "pin interrupt rising edge register", but would I have to set bits in the "Pin interrupt level (rising edge) interrupt enable register" to make it work?