Timer with PIC

Program:

#include<pic.h>

#include<htc.h>

#define __16f877A_H

__CONFIG(WDTE_OFF&LVP_OFF&FOSC_HS&PWRTE_ON);

void main()

{

unsigned int i;

TRISB=0x00;

OPTION_REG=0x01;

PORTB=0xff;

while(1)

{

for(i=0;i<3921;i++)

{

TMR0=0x00;

while(!TMR0IF);

TMR0IF=0;

}

TMR0=0x6f;

//while(!TMR0IF);

//TMR0IF=0;

PORTB=~PORTB;

}

}