#include <mc9s12dp512.h>     
#define SW PORTA_BIT7
#define ENABLE PORTB_BIT0
#define MTR_1 PORTB_BIT1
#define MTR_2 PORTB_BIT2
void main()
  {
  DDRA = DDRA & ~0x80;   
  DDRB = DDRB | 0x07;   
  SW = 1;
  ENABLE = 0;
  MTR_1 = 0;
  MTR_2 = 0;
  while(1)
    {
      ENABLE = 1;
      if(SW == 1)
        {
          MTR_1 = 1;
          MTR_2 = 0;
        }
      else
        {
          MTR_1 = 0;
          MTR_2 = 1;
        }
    }
  }