数码管显示00~59按键1每按一次显示值加一，按键2每按一次显示值减一，按键3功能归零，按键4启动或停止定时器0

#include<reg52.h>
#define uchar unsigned char 
#define uint unsigned int 
sbit key1=P3^4;
sbit key2=P3^5;
sbit key3=P3^6;
sbit key4=P3^7;
sbit dula=P2^6;
sbit wela=P2^7;
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71
};
void delayms(uint);
uchar numt0,num;
void display(uchar numdis)
{
uchar shi,ge;
shi=numdis/10;
ge=numdis%10;

dula=1;
P0=table[shi];
dula=0;
P0=0xff;
wela=1;
P0=0xfe;
wela=0;
delayms(5);

dula=1;
P0=table[ge];
dula=0;
P0=0xff;
wela=1;
P0=0xfd;
wela=0;
delayms(5);
}


void delayms(uint xms)
{
uint i,j;
for(i=xms;i>0;i--)
for(j=110;j>0;j--);
}
void init()
{
TMOD=0x01;
TH0=(65535-45872)/256;
TL0=(65536-45872)%256;
EA=1;
ET0=1;
}


void keyscan()
{
if(key1==0)
{
delayms(10);
if(key1==0)
{
num++;
if(num==60)
num=0;
while(!key1);
}
}
if(key2==0)
{
delayms(10);
if(key2==0)
{
if(num==0)
num=60;
num--;
while(!key2);
}
}
if(key3==0)
{
delayms(10);
if(key3==0)
{
num=0;
while(!key3);
}
}
if(key4==0)
{
delayms(10);
if(key4==0)
{
while(!key4);
TR0=~TR0;
}
}
}


void main()
{
init();
while(1)
{
keyscan();
display(num);
}
}
void T0_timer() interrupt 1
{
TH0=(65536-45872)/256;
//重装初值
TL0=(65536-45872)%256;
numt0++;
if(numt0==20)
{
numt0=0;
num++;
if(num==60)
num=0;
}
}