#include<at89x52.h>

const unsigned char code flook [][5] =

{

{ 0x3E, 0x51, 0x49, 0x45, 0x3E }, // 0

{ 0x00, 0x42, 0x7F, 0x40, 0x00 }, // 1

{ 0x42, 0x61, 0x51, 0x49, 0x46 }, // 2

{ 0x21, 0x41, 0x45, 0x4B, 0x31 }, // 3	  k*

{ 0x18, 0x14, 0x12, 0x7F, 0x10 }, // 4

{ 0x27, 0x45, 0x45, 0x45, 0x39 }, // 5

{ 0x3C, 0x4A, 0x49, 0x49, 0x30 }, // 6

{ 0x01, 0x71, 0x09, 0x05, 0x03 }, // 7

{ 0x36, 0x49, 0x49, 0x49, 0x36 }, // 8

{ 0x06, 0x49, 0x49, 0x29, 0x1E } // 9

};

const unsigned char code colon[]={0x00,0x18,0x00};

unsigned char a,b,c,d,e,f;

bit tog;

void Int0(void) interrupt 0 using 2

{

EX0=0;   // Avoid another INT1* until we are completely finished...

TH0=0xA4;

TR0=1;    // Start timer 0

}

void timer0(void) interrupt 1  using 3

{

static unsigned char i,k;

k++;

if(k==12)

{

k=0;

if(i<5)	  //hours ten digit

{

P0=~(flook[f][i]);

i++;

}

else if(i==5)//space

{

P0=0xFF;

i++;

}

else if(i<11)//space

{

P0=~(flook[(e%10)][i-6]);

i++;

}

else if(i<14)//colon

{

if(tog==1)

{

P0=~(colon[i-11]);

}

else

{

P0=0xFF;

}
i++;
}

else if(i<19)//min tens

{

P0=~(flook[d][i-14]);

i++;

}

else if(i==19)//space

{

P0=0xFF;

i++;

}

else if(i<25)//min one

{

P0=~(flook[c][i-20]);

i++;

}

else if(i<28)//colon

{

if(tog==1)

{

P0=~(colon[i-25]);

}

else

{

P0=0xFF;

}
i++;
}

else if(i<33)//sec tens

{

P0=~(flook[b][i-28]);

i++;

}

else if(i==33)//space

{

P0=0xFF;

i++;

}

else if(i<39)//sec ones

{

P0=~(flook[a][i-34]);

i++;

}

else

{TR0=0;

P0=0xFF;

EX0=1;

i=0;

}

}

}

void delay()

{

int fi,fj;

for(fi=0;fi<160;fi++)

{

for(fj=0;fj<1250;fj++)	;

}

}

void main()

{

TMOD=0x02;

TH0=0xA4;

EX0   = 1;                      /* External interrupt 0 enable              */

IT0   = 1;                      /* External interrupt 0 Edge sesitive       */

ET0   = 1;                      /* Enable Timer 0 interrupts                */

PT0   = 1;                      /* Timer 0 high priority                    */

PX0   = 1;                      /* External interrupt 0 high priority       */

/*-----------------------------------------------

Configure INT0 (external interrupt 0) to generate

an interrupt on the falling-edge of /INT0 (P3.2).

Enable the EX0 interrupt and then enable the

global interrupt flag.

-----------------------------------------------*/

EX0 = 1;   // Enable EX0 Interrupt

EA = 1;    // Enable Global Interrupt Flag

P0=0xFF;

P3=0xFF;

a=0;	  //sec one's

b=0;	  //sec ten's

c=0;	  //min one's

d=0;	  //min ten's

e=0;	  //hr one's

f=0;	  //hr ten's

tog=0;

while(1)

{

delay();

tog=~tog;

a++;

if(a>9)

{

a=0;

b++;

}

if(b>5)

{

b=0;

c++;

}

if(c>9)

{

c=0;

d++;

}

if(d>5)

{

d=0;

e++;

}

if(e>12)

{

e=0;

}

if(e>9)

{

f=1;

}

else

{

f=0;

}

}

}