#include

"

config.h

"

#define

LED1 (1 << 19)

#define

KEY1 (1 << 18)

void

DelayNS(uint32 dly)

{

uint32 i;

for

(;dly

>

0

; dly

--

)

{

for

(i

=

0

; i

<

50000

; i

++

);

}

}

void

WDTInit(uint32 uiTime)

{

WDTC

=

uiTime;

WDMOD

=

0x03

;

WDFEED

=

0xaa

;

WDFEED

=

0x55

;

}

void

FeedDog(

void

)

{

IRQDisable();

WDFEED

=

0xaa

;

WDFEED

=

0x55

;

IRQEnable();

}

int

main(

void

)

{

uint32 i;

PINSEL0

=

0x00000000

;

PINSEL1

=

0x00000000

;

IODIR

=

LED1;

IOCLR

=

LED1;

DelayNS(

100

);

IOSET

=

LED1;

WDTInit(

0x200000

);

while

(

1

)

{

while

((IOPIN

&

KEY1)

==

0

);

for

(i

=

0

; i

<

0xff

; i

++

);

FeedDog();

}

}

 

#include "config.h"

 

#define LED1 (1 << 19)

#define KEY1 (1 << 18)

void DelayNS(uint32 dly)

{

    uint32 i;

    for(;dly > 0; dly--)

    {

        for(i = 0; i < 50000; i++);

    }

}

void WDTInit(uint32 uiTime)

{

    WDTC = uiTime;

    WDMOD = 0x03;

   

   

    WDFEED = 0xaa;

    WDFEED = 0x55;

}

void FeedDog(void)

{

    IRQDisable();

    WDFEED = 0xaa;

    WDFEED = 0x55;

   

    IRQEnable();

}

int main(void)

{

    uint32 i;

    PINSEL0 = 0x00000000;

    PINSEL1 = 0x00000000;

   

    IODIR = LED1;

    IOCLR = LED1;

   

    DelayNS(100);

    IOSET = LED1;

   

    WDTInit(0x200000);

   

    while(1)

    {

        while((IOPIN & KEY1) == 0);

        for(i = 0; i < 0xff; i++);

        FeedDog();

    }

}

 

实验现象，正常情况下：上电后，LED会闪一下。因为定时喂狗，就这样一直不闪了。

我们通过按键来模拟意外事件。

 

当长按住按键时，因为不能定时的喂狗，所以LED就会不停的闪烁。