External Interrupt configuration in DUE board.

Hi, Friends.

I have switch connected to PIN no 2 of DUE board. I want to do following things.

  1. When Switch pressed (ON/CLOSED) it should go into ISR, in ISR i will make 3 LEDs ON Connected to DUE's Pin no 4,5 and 6.

2)When Switch is OFF/OPEN. it should work normal.

i tried arduino Mega's interrupt code as per Arduino's Instruction using

attachInterrupt(digitalPinToInterrupt(interruptPin), ISR, FALLING);

but using this Interrupt works for only single time. and not getting proper working like it happens in AVR.

i am looking for CORE Code, So that it may give clear picture to what happen inside controller. i mean which register need to select etc..

i am also looking for some good tutorials if anyone has any links where these explanation is available for beginner.

Thanks in advance