N76E003配置看门狗watchdog

说明

本例子只做软件异常时重置系统用，不需要用作定时器或唤醒用，所以不用打开watchdog中断。需要注意的是：如果上次启动开启过watchdog reset，想要关闭，下次启动必须清除CONFIG4内的WDT配置，否则watchdog还是启动的。

主要代码只是在CONFIG4寄存器对看门狗定时器WDT做使能关闭的配置（[7:4]，0xF0关闭重置只做定时器，0x50和其他任意值开启重置，但0x50在空闲或掉电模式下停止运行），由于是页擦除，所以先保存CONFIG0到CONFIG4的值再写入。

在操作前要执行TA时效访问保护。

参考代码

#include "N76E003.h"

#include "SFR_Macro.h"

#include "Function_define.h"

#include "Common.h"

#include "Delay.h"

#define EN_WATCHDOG

#define CRLF "rn"

#define     CFG_READ            0xC0

#define     CFG_ERASE           0xE2

#define     CFG_BYTE_PROGRAM    0xE1

int is_watchdog_reset_enabled(void)

{

UINT8 cf4;

set_IAPEN;

IAPAL = 0x04;

IAPAH = 0x00;

IAPCN = CFG_READ;

set_IAPGO;                                  //get CONFIG4 data

cf4 = IAPFD;

clr_IAPEN;

//printf("watchdog: cf4=0x%bX"CRLF, cf4);

if ((cf4 & 0xF0) == 0xF0)

{

return 0;

}

else if ((cf4 & 0xF0) == 0x50)

{

return 1; // watchdog reset enabled, but disabled in idle and power down mode

}

else

{

return 2; // watchdog reset enabled, but enabled in idle and power down mode

}

}

#ifdef EN_WATCHDOG

#define FEED_DOG()  set_WDCLR

/***********************************************************************

WDT CONFIG enable 

warning : this macro is only when ICP not enable CONFIG WDT function

copy this marco code to you code to enable WDT reset.

************************************************************************/

void Enable_WDT_Reset_Config(void)

{

set_IAPEN;

    IAPAL = 0x04;

    IAPAH = 0x00;

    IAPFD = 0x5F; //0x0F; // CONFIG4

    IAPCN = CFG_BYTE_PROGRAM;

    set_CFUEN;

    set_IAPGO;                                  //trigger IAP

while((CHPCON&SET_BIT6)==SET_BIT6);          //check IAPFF (CHPCON.6)

    clr_CFUEN;

    clr_IAPEN;

}

#else

/***********************************************************************

WDT CONFIG disable 

warning : this macro is for CONFIG already enable WDT Reset to disable.

Since erase CONFIG is full page 

step 1. storage CONFIG value in RAM

step 2. modify RAM CONFIG4 WDT value to disable 

step 3. erase CONFIG page

step 4. re writer CONFIG.

************************************************************************/

void Disable_WDT_Reset_Config(void)

{

UINT8 cf0,cf1,cf2,cf3,cf4;

set_IAPEN;

IAPAL = 0x00;

IAPAH = 0x00;

IAPCN = CFG_READ;

set_IAPGO;                                  //Storage CONFIG0 data

cf0 = IAPFD;

IAPAL = 0x01;

set_IAPGO;                                  //Storage CONFIG1 data

cf1 = IAPFD;

IAPAL = 0x02;

set_IAPGO;                                  //Storage CONFIG2 data

cf2 = IAPFD;

IAPAL = 0x03;

set_IAPGO;                                  //Storage CONFIG3 data

cf3 = IAPFD;

IAPAL = 0x04;

set_IAPGO;                                  //Storage CONFIG4 data

cf4 = IAPFD;

cf4 |= 0xF0; //Moidfy Storage CONFIG4 data disable WDT reset

set_CFUEN;

IAPCN = CFG_ERASE; //Erase CONFIG all

IAPAH = 0x00;

IAPAL = 0x00;

IAPFD = 0xFF;

set_IAPGO;

IAPCN = CFG_BYTE_PROGRAM; //Write CONFIG

IAPFD = cf0;

set_IAPGO;

IAPAL = 0x01;

IAPFD = cf1;

set_IAPGO;

IAPAL = 0x02;

IAPFD = cf2;

set_IAPGO;

IAPAL = 0x03;

IAPFD = cf3;

set_IAPGO;

IAPAL = 0x04;

IAPFD = cf4;

set_IAPGO;

clr_CFUEN;

clr_IAPEN;

}

#endif /* EN_WATCHDOG */

void init_watchdog(void)

{

printf("watchdog: WDCON=0x%bX"CRLF, WDCON);

if (WDCON & SET_BIT3) // WDTRF

{

printf("WARNING: Last time, the system was reset by the watchdog!"CRLF);

clr_WDTRF;

}

//----------------------------------------------------------------------------------------------

// WDT Init !!! ENABLE CONFIG WDT FIRST !!!

// Warning:

// Always check CONFIG WDT enable first, CONFIG not enable, SFR can't enable WDT reset

// Please call Enable_WDT_Reset_Config() function to enable CONFIG WDT reset

//----------------------------------------------------------------------------------------------

if (is_watchdog_reset_enabled())

{

#ifndef EN_WATCHDOG

Disable_WDT_Reset_Config(); //Software disable WDT reset CONFIG setting

return;

#endif

}

else

{

#ifdef EN_WATCHDOG

Enable_WDT_Reset_Config(); //Software enable WDT reset CONFIG setting

#endif

}

#ifdef EN_WATCHDOG

TA=0xAA;TA=0x55;WDCON|=0x07; //Setting WDT prescale 

set_WDCLR; //Clear WDT timer

while((WDCON|~SET_BIT6)==0xFF); //confirm WDT clear is ok before into power down mode

// EA = 1;

set_WDTR; //WDT run

#endif

}

void main(void)

{

init_watchdog();

while(1)

{

#ifdef EN_WATCHDOG

FEED_DOG();

#endif

printf("main: do something.."CRLF);

}

}