wdt.c

lpc2148-keil环境下的各个功能模块的例程

/*****************************************************************************
 *   wdt.c:  Watchdog C file for Philips LPC214x Family Microprocessors
 *
 *   Copyright(C) 2006, Philips Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2005.10.01  ver 1.00    Prelimnary version, first Release
 *
*****************************************************************************/
#include "LPC214x.H"                        /* LPC21xx definitions */
#include "type.h"
#include "irq.h"
#include "timer.h"
#include "wdt.h"

DWORD wdt_counter;

/*****************************************************************************
** Function name:		WDTHandler
**
** Descriptions:		Watchdog timer interrupt handler
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
void WDTHandler(void) __irq 
{
    WDMOD &= ~WDTOF;		/* clear the time-out terrupt flag */		  
    IENABLE;			/* handles nested interrupt */
    wdt_counter++;
    IDISABLE;
    VICVectAddr = 0;		/* Acknowledge Interrupt */
}

/*****************************************************************************
** Function name:		WDTInit
**
** Descriptions:		Initialize watchdog timer, install the
**				watchdog timer interrupt handler
**
** parameters:			None
** Returned value:		true or false, return false if the VIC table
**				is full and WDT interrupt handler can be
**				installed.
** 
*****************************************************************************/
DWORD WDTInit( void )
{
    wdt_counter = 0;
    if ( install_irq( WDT_INT, (void *)WDTHandler ) == FALSE )
    {
	return (FALSE);
    }

    WDTC = WDT_FEED_VALUE;	/* once WDEN is set, the WDT will start after 
				feeding */
    WDMOD = WDEN | WDRESET;

    WDFEED = 0xAA;		/* Feeding sequence */
    WDFEED = 0x55;    
    return( TRUE );
}

/*****************************************************************************
** Function name:		WDTFeed
**
** Descriptions:		Feed watchdog timer to prevent it from timeout
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
void WDTFeed( void )
{
    WDFEED = 0xAA;		/* Feeding sequence */
    WDFEED = 0x55;
    return;
}

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