#include <reg51.h>
unsigned char code seg7[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f} //數(shù)碼管碼表
unsigned char code tab[]={0xfe,0xfd}; //數(shù)碼管位選
unsigned char cnt=0; //位選變量
unsigned char deta=0,sec=0; //0.01秒變量，和秒變量
sbit stop=P3^3; //暫停鍵
void init() //定時(shí)初始化
{
TMOD=0x11;
TH1=0xd8;
TL1=0xf0;
TR1=1;
TH0=0xfc;
TL0=0x18;
TR0=1;
ET1=1;
ET0=1;
EA=1;
}
void time10ms()interrupt 3
{
TH1=0xd8;
TL1=0xf0;
deta++;
}
void show()interrupt 1 //掃描顯示2位數(shù)碼管
{
TH0=0xfc;
TL0=0x18;
++cnt;
if(cnt>1)cnt=0;
switch (cnt)
{
case 0: P0=seg7[sec%10];P2=tab[0];break;
case 1: P0=seg7[sec/10];P2=tab[1];break;
default:break;
}
}
void showtime() //時(shí)間顯示
{
if((deta>10)&&stop){sec++;deta=0;} //如果P3^3 不按下，則為高電平，不暫停時(shí)間。
if(sec==99)sec=0;
}
void main()
{
init();
while(1)
{
showtime();
}
}