#include <mc9s12dp512.h>     
void MSDelay(unsigned int);
#define Dsensor PORTB_BIT1
#define buzzer PORTA_BIT7
void main(void)
  {
    DDRB_BIT1 = DDRB & ~0x02;		
    DDRA_BIT7 = DDRA | 0x80;		
    while(1)
    {
      while(Dsensor == 1)
        { 
          buzzer = 0;
          MSDelay(2);
          buzzer = 1;
          MSDelay(2);
        }
    }
  }