1.   Connect TWO debounced push buttons to LPC1114FN28 DIP module with external pullup resistors
2.   Connect THREE active high LED to LPC1114FN28 DIP module
3.   Make sure push buttons generate clean active low pulse when pressed
4.   Download following program to LPC1114FN28 DIP module
5.   Press and hold and release Button2
6.   TWO LED will be on, one is on when press, another one is on when release
7.   Press and hold and release Button1
8.   TWO LED will be off, one is off when press, another one is off when release

#include "mbed.h"

DigitalOut  LedR (dp14);
DigitalOut  LedY (dp17);
DigitalOut  LedG (dp18);

InterruptIn Btn1 (dp26);
InterruptIn Btn2 (dp28);

void ISR_Btn1Rise ()
{
	NVIC_DisableIRQ (EINT0_IRQn);

    volatile uint32_t d = 0;
    volatile uint32_t s = 1;

    for (d = 0; d < 10000; d++) {s = Btn1.read ();}  // Debounce

    if      (s            == 0) {}
    else if (LedR.read () == 1) {LedR = 0;}
	else if (LedY.read () == 1) {LedY = 0;}
	else if (LedG.read () == 1) {LedG = 0;}

	NVIC_EnableIRQ  (EINT0_IRQn);
}

void ISR_Btn2Rise ()
{
	NVIC_DisableIRQ (EINT0_IRQn);

    volatile uint32_t d = 0;
    volatile uint32_t s = 1;

    for (d = 0; d < 10000; d++) {s = Btn2.read ();}  // Debounce

    if      (s            == 0) {}
    else if (LedR.read () == 0) {LedR = 1;}
	else if (LedY.read () == 0) {LedY = 1;}
	else if (LedG.read () == 0) {LedG = 1;}

	NVIC_EnableIRQ  (EINT0_IRQn);
}

int main ()
{
	LedR = 0;
	LedY = 0;
	LedG = 0;

	Btn1.mode (PullNone);
	Btn2.mode (PullNone);

	Btn1.rise (&ISR_Btn1Rise);
	Btn2.rise (&ISR_Btn2Rise);

    while (1)
    {
    }
}