TIMER2 MODULE OF PIC16F877A

Timer2 is an 8-bit timer with a prescaler and a postscaler. It can be used as the PWM time base for the PWM mode of the CCP module(s). The TMR2 register is readable and writable and is cleared on any device Reset. The input clock (FOSC/4) has a prescale option of 1:1, 1:4 or 1:16, selected by control bits T2CKPS1:T2CKPS0 (T2CON<1:0>).The Timer2 module has an 8-bit period register, PR2.Timer2 increments from 00h until it matches PR2 and then resets to 00h on the next increment cycle. PR2 is a readable and writable register. The PR2 register is initialized to FFh upon Reset.
The match output of TMR2 goes through a 4-bit postscaler (which gives a 1:1 to 1:16 scaling inclusive) to generate a TMR2 interrupt (latched in flag bit, TMR2IF (PIR1<1>)). Timer2 can be shut-off by clearing control bit, TMR2ON (T2CON<2>), to minimize power consumption.

Program to Generate a 1s delay ....

#include<pic.h>
void timer();
void main()
{
TRISD=0X00;
T2CON=0X7E;
while(1)
{
PORTD=0XFF;
timer();
PORTD=0X00;
timer();
}
}
void timer()
{
int i;
TMR2=0X00;
for(i=0;i<15;i++)
{
while(TMR2IF==0);
TMR2IF=0;
}
}