LPC43xx code for GPIO pin interrupts, ripped from the quadrature encoder code of my HackRF spectrum analyzer. (I should clean up that code and post it someday...)

gistfile1.cpp

// Pin configuration.

scu_pinmux(SCU_SD_CD, SCU_GPIO_PUP | SCU_CONF_FUNCTION0);
scu_pinmux(SCU_SD_DAT3, SCU_GPIO_PUP | SCU_CONF_FUNCTION0);
SCU_PINTSEL0 =
	(1 << 13) |		// GPIO1[6]
	(6 <<  8) |
	(1 <<  5) |		// GPIO1[5]
	(5 <<  0)
	;

// Interrupt configuration.

GPIO_PIN_INTERRUPT_ISEL =
	(0 << 1) |	// 1: edge-sensitive
	(0 << 0)	// 0: edge-sensitive
	;
GPIO_PIN_INTERRUPT_IENR =
	(1 << 1) |	// 1: Enable rising-edge interrupt
	(1 << 0)	// 0: Enable rising-edge interrupt
	;
GPIO_PIN_INTERRUPT_IENF =
	(1 << 1) |	// 1: Enable falling-edge interrupt
	(1 << 0)	// 0: Enable falling-edge interrupt
	;

nvic_set_priority(NVIC_M4_PIN_INT0_IRQ, 255);
nvic_enable_irq(NVIC_M4_PIN_INT0_IRQ);
nvic_set_priority(NVIC_M4_PIN_INT1_IRQ, 255);
nvic_enable_irq(NVIC_M4_PIN_INT1_IRQ);	

// Interrupt handlers.

void pin_int0_irqhandler() {
	if( GPIO_PIN_INTERRUPT_IST & (1 << 0) ) {
		encoder_update();
		GPIO_PIN_INTERRUPT_IST = (1 << 0);
		GPIO_PIN_INTERRUPT_RISE = (1 << 0);
		GPIO_PIN_INTERRUPT_FALL = (1 << 0);
	}
}

void pin_int1_irqhandler() {
	if( GPIO_PIN_INTERRUPT_IST & (1 << 1) ) {
		encoder_update();
		GPIO_PIN_INTERRUPT_RISE = (1 << 1);
		GPIO_PIN_INTERRUPT_FALL = (1 << 1);
		GPIO_PIN_INTERRUPT_IST = (1 << 1);
	}
}