單片機80c51設計壹個兩位計數器,能對外部的脈沖進行計數，能進行復位。

#define uchar unsigned char;

uchar distab[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x00}; //0到f

uchar number,dat;

void ext0() interrupt 0

{

dat++;

dat%=100;

}

void t0isr() interrupt 1

{

TH0=(65536-5000)/256;

TL0=(65536-5000)%256;

number++;

if(number>1)number=0;

switch(number)

{

case 0:P2=0x02;P0=distab[dat/10];

break;

case 1:P2=0x01;P0=distab[dat%10];

break;

default:break;

}

}

main()

{

TMOD=0x01;

TH0=(65536-5000)/256;

TL0=(65536-5000)%256;

TR0=1;

ET0=1;

EX0=1;

IT0=1;

PX0=1;

EA=1;

while(1);

}