--> 6 digit Frequency counter using AT89S51

This project is done with help of AT89S51 microcontroller. The T0 & T1 timers of the At89s51 is used to measure the frequency of the input clock. This project can measure clock frequencies upto 250Khz.
Circuit Diagram:

Circuit Connections:

1. P0.0 to P0.7 is connected to the ABCDEFG segments of the display.
2. P2.0 to P2.7 is connected to the S1S2S3S4S5S6S7S8 of the displays.
3. The input signal is fed to the P3.4

C Program:
[code:c]#include
unsigned char code dispbit[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
unsigned char code dispcode[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x00,0x40};
unsigned char dispbuf[8]={0,0,0,0,0,0,10,10};
unsigned char temp[8];
unsigned char dispcount;
unsigned char T0count;
unsigned char timecount;
bit flag;
unsigned long x;

void main(void)
{
  unsigned char i;
  TMOD=0x15;
  TH0=0;
  TL0=0;
  TH1=(65536-4000)/256;
  TL1=(65536-4000)%256;
  TR1=1;
  TR0=1;
  ET0=1;
  ET1=1;
  EA=1;

  while(1)
   {
     if(flag==1)
       {
         flag=0;
         x=T0count*65536+TH0*256+TL0;
         for (i=0; i<8; i++)
           {
             temp[i]=0;
           }
         i=0;
         while(x/10)
           {
             temp[i]=x%10;
             x=x/10;
             i++;
           }
         temp[i]=x;
         for (i=0; i<6; i++)
           {
             dispbuf[i]=temp[i];
           }
         timecount=0;
         T0count=0;
         TH0=0;
         TL0=0;
         TR0=1;
       }
   }
}

void t0(void) interrupt 1 using 0
{
  T0count++;
}

void t1(void) interrupt 3 using 0
{
  TH1=(65536-4000)/256;
  TL1=(65536-4000)%256;
  timecount++;
  if(timecount==250)
    {
      TR0=0;
      timecount=0;
      flag=1;
    }
  P0=dispcode[dispbuf[dispcount]];
  P2=dispbit[dispcount];
  dispcount++;
  if(dispcount==8)
    {
      dispcount=0;
    }
}
[/code]