用C语言编写秒表的程序（单片机控制的时钟设计）

这个程序可以实现秒的计时，按键控制开始、暂停、清零功能，更多功能自己在看清程序的基础上进行改进。

#include <reg51.H>

sbit P3_5 =P3^5

unsigned char code dispcode[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,

0x80,0x90,0x88,0x83,0xC6,0xA1,0x86,0x8E,0x00}

unsigned char second

unsigned char keycnt

unsigned int tcnt

void main(void)

{

unsigned char i,j

TMOD=0x02

ET0=1

EA=1

second=0

P1=dispcode[second/10]

P2=dispcode[second%10]

while(1)

{

if(P3_5==0)

{

for(i=20i>0i--)

for(j=248j>0j--)

if(P3_5==0)

{

keycnt++

switch(keycnt)

{

case 1:

TH0=0x06

TL0=0x06

TR0=1

break

case 2:

TR0=0

break

case 3:

keycnt=0

second=0

P1=dispcode[second/10]

P2=dispcode[second%10]

break

}

while(P3_5==0)

}

}

}

}

void t0(void) interrupt 1 using 0

{

tcnt++

if(tcnt==4000)

{

tcnt=0

second++

if(second==100)

{

second=0

}

P1=dispcode[second/10]

P2=dispcode[second%10]

}

}

#include

#define

uchar

unsigned

char

uchar

distab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xff}

uchar

times,num

void

t0isr()

interrupt

1

{

TH0=(65536-50000)/256

//重置初值

TL0=(65536-50000)%256

times++

if(times>=20)

//1秒是否到

{

times=0

num--

//1秒到后，计数值减1

P0=distab[num]

//显示

if(num==0)num=9

//到0后再赋值为9

}

}

main()

{

TMOD=0x01

//定时器0为16为定时

TH0=(65536-50000)/256

//50毫米中断一次

TL0=(65536-50000)%256

ET0=1

EA=1

num=9

times=0

TR0=1

while(1)

}

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