#include <mc9s12dp512.h>     
#define MTR  PORTB_BIT0
void MSDelay(unsigned int value);
void main()
  {
  unsigned int duty;
  DDRB = 0x01;
  DDRA = 0xFC;
  while(1)
    {
	duty = PORTA&0x03;	
     duty++;
     duty *= 25;
     MTR = 0;
     MSDelay(duty);		
     MTR = 1;
     MSDelay(100-duty);	
    }
  }