单片机：按秒计时，10秒响一次 每秒LED0 1亮 10进制

#include<reg51.h>
#define uchar unsigned char;
#define uint unsigned int;
uchar position;           
uchar tt,bz1=0,bz2=0,bz3=0;             
uint second;       
uchar minute;
uchar hour;       
uchar code table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};//0--9
sbit smg_q = P2^0; 
sbit smg_b = P2^1; 
sbit smg_s = P2^2;
sbit smg_g = P2^3;
sbit key1=P3^2;                 
sbit key2=P3^3;
sbit key3=P3^4;
sbit key4=P3^5;
sbit led1=P1^0;
sbit led2=P1^1;
sbit led3=P1^2;
sbit led4=P1^3;
sbit led5=P1^4;
sbit led6=P1^5;
sbit beep=P2^5;
void keyscan();                   
void display(unsigned int second);
void delay(unsigned int timer);
void init(); 
void main()
{
    init();                                    
   while(1)
      {
       if(tt==20)
                 { led1=~led1;led2=~led2;
                     if (bz1==10)
                     {
                     beep=0;
                     bz1=0;}
                     bz1=bz1+1;
                     
           tt=0;
           second++;
          
           }
           keyscan();
           display(second);      
          delay(1);
                     beep=1;
         }
}
void keyscan()
{  if(key1==0)     
     {
      TR0=1;
      }
   if(key2==0)               
     {
    TR0=1;
     }
  if(key3==0)    
    {
     
    TR0=1;
    }
  if(key4==0)          
   {
    
   TR0=1;
   }
}
void init()
{
    tt=0;
    position=0;               
    second=0; 
    minute=0;        
    hour=0;   
    smg_q=1;
    smg_b=1;
    smg_s=1;
    smg_g=1;
    key1=1;
    key2=1;
    TMOD=0X01;  
    TH0=0x4c;        
    TL0=0x00;
    EA=1;                
    ET0=1;              
    TR0=1;              
}
void t0() interrupt 1
{
  TH0=0x4c;        
  TL0=0x00;
  tt++;

}
void display(unsigned int second)
{     P0=0XFF;                             
      switch(position)
      {
       case 0:   smg_g=1;smg_q=0;P0=table[second/1000]; break;
       case 1:   smg_q=1;smg_b=0; P0=table[(second-second/1000*1000)/100];break;
       case 2:   smg_b=1;smg_s=0;P0=table[(second-second/100*100)/10];break;
       case 3:   smg_s=1;smg_g=0;P0=table[(second-second/100*100)%10];if(tt>=10) P0&=0x7f; break;
       }
      position++;               
      if(position>3)
          position=0;      
}
void delay(unsigned int time)
{                
   unsigned int x,y;
   for(x=time;x>0;x--)
     for(y=110;y>0;y--);
}