*/ 
// Define LED connection 
sbit LED at RB0_bit; 
unsigned short Num; 
// Interrupt service routine 
void interrupt() { 
  Num ++;           // Interrupt causes Num to be incremented by 1 
  if(Num == 18) { 
   LED = ~LED;       // Toggle LED every sec 
   Num = 0; 
  } 
  TMR0 = 39;        // TMR0 returns to its initial value 
  INTCON.T0IF = 0;  // Bit T0IF is cleared so that the interrupt could reoccur 
} 
void main() { 
 CMCON = 0x07 ; // Disbale comparators 
TRISB = 0b00000000; // PORTB All Outputs 
TRISA = 0b00100000; // PORTA All Outputs, Except RA5=MCLR 
 LED = 0; 
 Num = 0; 
 OPTION_REG = 0x07; // Prescaler (1:256) is assigned to the timer TMR0 
 TMR0 = 39;          // Timer T0 counts from 39 to 255 
 INTCON = 0xA0;     // Enable interrupt TMR0 and Global Interrupts 
 do { 
 // You main programs goes here 
 } while(1);  // infinite loop 
}