单片机60s倒计时程序c语言

#define uchar unsigned char

sbit P13=P1^3;

sbit P14=P1^4;

uchar c,i,a=60,z;

uchar code Numcode[]={0XC0,//;0

0XF9,//;1

0XA4,//;2

0XB0,//;3

0X99,//;4

0X92,//;5

0X82,//;6

0XF8,//;7

0X80,//;8

0X90,//;9

};

void delay(z)

{ while(z--);

}

void main()

{TMOD=1;

TH0=(65536-50000)/256;

TL0=(65536-50000)%256;

c=0;

i=0;

EA=1;

ET0=1;

TR0=1;

while(1)

{ if(c==20)

{ c=0;

a--;}

if(a>=0)

{i=a/10;

P13=1;

P0=Numcode[i];

P14=0;

delay(20);

P14=1;

i=a%10;

P0=Numcode[i];

P13=0;

delay(10);}

else

{a=60;}

}

}

void timer0() interrupt 1

{TH0=(65536-50000)/256;

TL0=(65536-50000)%256;

c++;

}