/****************************************************************************
			59秒計時器的設計
******************************************************************************/
#include"reg51.h"
#define uchar unsigned char
#define uint unsigned int
sbit p21=P2^1;
sbit p20=P2^0;
uint t=0;
uchar count;
uchar counth,countl;
const uchar tab[]={  0XC0,0XF9,0XA4,0XB0,0X99,/*0~9*/
                     0X92,0X82,0XF8,0X80,0X90};
void delay(void)     //延時
{         uint i;
          for(i=0;i<244;i++);
}
void time0_server_(void) interrupt 1
{   
	TH0=0x3C;      //定時時間為 50ms  12MHZ的晶振
    TL0=0xB0;
	t++;
}
void Init_t0(void)    //定時器初始化
{
      TMOD=0X01;     //選擇方式1
	  TH0=0x3C;
      TL0=0xB0;
 	  EA=1;
      ET0=1;
      TR0=1;  
}
void display(void)
 {counth=count/10;
  countl=count%10;
  P1=tab[counth];   //十位顯示
  p21=1;
  delay();
  p21=0;
  P1=tab[countl];   //十位顯示
  p20=1;
  delay();
  p20=0;
 }
void main(void)
{   count=0;
      while(1)                     //0到99的顯示
	     {if(t==20)
		   {if(count==59)
	         count=0;}
			t=0;
			count++;
			display();
   }   
}