Programmtechnische Frage PIC16F877A

void main (void)

{

  unsigned long int ADC_VALUE;

  TRISC = 0b00000000;

  TRISA = 0b11111111;

  ADCON1  = 0b10001110;

  ADCON0  = 0b11000001;

  while (1)

  {    

    ADIE  =  0;                                                  

    ADRESL  = 0;             

    ADRESH  = 0;              

     GO = 1;

    while(GO != 0) continue;               

    ADC_VALUE  = ADRESL;            

    ADC_VALUE  += (ADRESH << 8);          

    if (ADC_VALUE > 500)

    {

      PORTC |= 0b00001000;

      PORTC &= 0b11101111;

    }

    if (ADC_VALUE <= 500)

    {      

      PORTC |= 0b00010000;

      PORTC &= 0b11110111;

    }

  }

}