I am using LPC1837, i need to enable active low interrupt in individual GPIO PIN.
/* enable GPIO port clock */
GPIO_PortClock(1);
/* Set GPIO6[0] pin and GPIO6[2] as input */
GPIO_SetDir(6,0,GPIO_DIR_INPUT);
GPIO_SetDir(6,2,GPIO_DIR_INPUT);
/* enable pin as GPIO Mode pin in pin multiplexing*/
SCU_PinConfigure(0xC,1,( SCU_CFG_MODE_FUNC4 | SCU_SFS_EPUN | SCU_SFS_ZIF ));
SCU_PinConfigure(0xC,3,( SCU_CFG_MODE_FUNC4 | SCU_SFS_EPUN | SCU_SFS_ZIF ));
/* set values for PINTSEL0 to choose GPIO Port 6,pin no 0 on INTPIN0 */
SCU_PinInterruptSourceSelect(0x00, 0x06, 0x00);
/* set values for PINTSEL0 to choose GPIO Port 6,pin no 2 on INTPIN1 */
SCU_PinInterruptSourceSelect(0x01, 0x06, 0x02);
/* enable level interrupt */
LPC_GPIO_PIN_INT->ISEL = (GPIO_PIN_INT_ISEL_PMODE0_Msk |
GPIO_PIN_INT_ISEL_PMODE1_Msk);
/* enable level interrupt */
LPC_GPIO_PIN_INT->IENR = (GPIO_PIN_INT_IENR_ENRL0_Msk |
GPIO_PIN_INT_IENR_ENRL1_Msk );
LPC_GPIO_PIN_INT->SIENR = ( GPIO_PIN_INT_SIENR_SETENRL0_Msk |
GPIO_PIN_INT_SIENR_SETENRL1_Msk );
/* enable active LOW interrupt */
LPC_GPIO_PIN_INT->IENF = 0x00UL;
LPC_GPIO_PIN_INT->CIENF = (GPIO_PIN_INT_CIENF_CENAF0_Msk |
GPIO_PIN_INT_CIENF_CENAF1_Msk );
/* enable active HIGH level interrupt */
/*
LPC_GPIO_PIN_INT->IENF = ( GPIO_PIN_INT_IENF_ENAF0_Msk |
GPIO_PIN_INT_IENF_ENAF1_Msk );
LPC_GPIO_PIN_INT->SIENF = (GPIO_PIN_INT_SIENF_SETENAF0_Msk |
GPIO_PIN_INT_SIENF_SETENAF1_Msk );
*/
// NVIC->ICPR[(((uint32_t)(int32_t)33) >> 5UL)] = (uint32_t)(1UL << (((uint32_t)(int32_t)33) & 0x1FUL));
NVIC->ISER[(((uint32_t)(int32_t)33) >> 5UL)] = (uint32_t)(1UL << (((uint32_t)(int32_t)33) & 0x1FUL));
