extint.c

NXP LPC系列AMR7的开发程序源码（LCD

/*****************************************************************************
 *   extint.c:  External interrupt API C file for NXP LPC23xx/24xx 
 *   Family Microprocessors
 *
 *   Copyright(C) 2006, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2006.07.13  ver 1.00    Prelimnary version, first Release
 *
*****************************************************************************/
#include "LPC230x.h"                        /* LPC23xx/24xx definitions */
#include "type.h"
#include "irq.h"
#include "extint.h"

#include <intrinsics.h>

volatile DWORD eint0_counter;

/*****************************************************************************
** Function name:		EINT0_Handler
**
** Descriptions:		external INT handler
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
__irq __nested __arm void EINT0_Handler (void)
{
    EXTINT = EINT0;		/* clear interrupt */

    __enable_interrupt();       /* handles nested interrupt */

    eint0_counter++;
    if ( eint0_counter & 0x01 )	/* alternate the LED display */
    {
		FIO2SET = 0x0000000F;	/* turn off P2.0~3 */
		FIO2CLR = 0x000000F0;	/* turn on P2.4~7 */
    }
    else
    {
		FIO2SET = 0x000000F0;	/* turn on P2.0~3 */
		FIO2CLR = 0x0000000F;	/* turn off P2.4~7 */
    }

    VICVectAddr = 0;		/* Acknowledge Interrupt */
}

/*****************************************************************************
** Function name:		EINTInit
**
** Descriptions:		Initialize external interrupt pin and
**				install interrupt handler
**
** parameters:			None
** Returned value:		true or false, return false if the interrupt
**				handler can't be installed to the VIC table.
** 
*****************************************************************************/
DWORD EINTInit( void )
{
    PINSEL4 = 0x00100000;	/* set P2.10 as EINT0 and P2.0~7 GPIO output */
    FIO2DIR = 0x000000FF;	/* port 2, bit 0~7 only */
    FIO2CLR = 0x000000FF;	/* turn off LEDs */

    IO2_INT_EN_F = 0x200;	/* Port2.10 is falling edge. */
    EXTMODE = EINT0_EDGE;	/* INT0 edge trigger */
    EXTPOLAR = 0;		/* INT0 is falling edge by default */

    if ( install_irq( EINT0_INT, (void *)EINT0_Handler, HIGHEST_PRIORITY ) == FALSE )
    {
		return (FALSE);
    }

    return( TRUE );
}

/******************************************************************************
**                            End Of File
******************************************************************************/