00~99 up down

#include <at89x52.h>

char P0table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};

char P2table[]={0xfe,0xfd};

char bdata flag;

sbit up_flag=flag^0;

sbit down_flag=flag^1;

char bcd[]={0,0};

int count=0;

int time=20;

int j;

sbit btn1=P3^0;

void delay_1ms(int k)

{

int i,j;

for(i=0;i<k;i++)

for(j=0;j<114;j++)

      ;

}

main()

{

IE=0x8A;

TMOD=0x10;

TH0=(8192-5000)/32;

TL0=(8192-5000)%32;

TH1=(65536-50000)/256;

TL1=(65536-50000)%256;

TR0=1;

TR1=1;

up_flag=1;

down_flag=0;

while(1)

{

if(btn1==0)

{

up_flag=~up_flag;down_flag=~down_flag;delay_1ms(20);while(btn1!=1);delay_1ms(20);

}

}

}

void t0_int0(void) interrupt 1

{

TH0=(8192-5000)/32;

TL0=(8192-5000)%32;

P0=P0table[bcd[j]];

P2=P2table[j];

j++;

if(j==2)

j=0;

}

void t1_int0(void) interrupt 3

{

TH1=(65536-50000)/256;

TL1=(65536-50000)%256;

time--;

if(time==0)

{

time=20;

if(up_flag==1)

{

  count++;

  if(count>99)

  count=0;

}

else if(down_flag==1)

{

count--;

if(count<0)

count=99;

}

bcd[0]=count%10;

bcd[1]=count/10;

}

}