#include <reg51.h>
#define uchar  unsigned char
#define uint   unsigned int
#define A   5
sbit  P1_0=P1^0;
sbit  P1_1=P1^1;
uchar msn=A;
bit idata tf=0;

uint count(void)
{
  P1_0=0;P1_0=1;
  TMOD=0x59;
  TH0=0x3c;TL0=0xb0; /*T/C0--timer*/
  TH1=0x00;TL1=0x00; /*T/C1--counter*/
  TR0=1;TR1=1;PT0=1;ET0=1;ET1=1;EA=1;EA=1;
  P1_1=0; P1_1=1;
  while(tf!=1);
  P1_0=0;P1_0=1;
  TR0=0;TR1=0;
  return(TH1*256+TL1);
}

void timer0(void) interrupt 1 using 1
{
  TH0=0x3c;
  TL0=0xb0;
  msn--;
  if(msn==0) {msn=A;tf=1;}
}

void timer1(void) interrupt 3 { }

void main(void)
{
  float rate;
  rate=(10/A)*count();
}