*program to find the toff*/

PLEASE FIND D CODE BELOW AND SUGGEST CHANGES I NEED TO MAKE TO GET "OFF TIME OF SQUARE PULSE".. .
i am using EX0 and TR0 interrupt to find low pulse time.

THANKS IN ADVANCE.

/*program to find the toff*/

#include <reg51.h>
#include <stdio.h>

sbit led=P1^0;

unsigned int count = 0,flag=0;

void EX0_ISR (void) interrupt 0
{ TR0=1; if(INT0) TR0=0; EX0=0;
}

void ET0_ISR(void) interrupt 1
{ count++; TF0=0;
}

void main (void)
{ SCON = 0x50; TMOD = 0x20; //timer 1 mode 2 auto reload TH1=-3;//9600 //TH1 = 0xFA; //Baud=9600 or -6d TR1 = 1; TI = 1; //PCON = 0x80; //setting SMOD TMOD = (TMOD & 0xF0) | 0x09; //value of TMOD =0x29 timer 0 for 16 bit mode 1

EA=EX0=ET0=1;

count=0; TH0=TL0=0;

while(1) { IT0=1; result=((unsigned long)((TH0<< 8) |TL0 | ((unsigned long)count << 16))); printf ("\noff pulse... %ld nSec\n", result);

} }

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