main.c

rotary encoder interrupt example on HCS12 using IRQ

#include <hidef.h>      /* common defines and macros */
#include <mc9s12db128.h>     /* derivative information */
#pragma LINK_INFO DERIVATIVE "mc9s12db128a"

signed char epos;

#pragma CODE_SEG NON_BANKED
void interrupt 6 IRS(void) 
{
  if((PORTB & 0x80) == 0x80){
    epos--;
  } else
  
    if((PORTB & 0x80) == 0x00)
    epos++;
}


#pragma CODE_SEG DEFAULT
void main(void) {
  /* put your own code here */
  DDRB = 0x00;     //FF is output  00 is input
  
  
  EnableInterrupts;
  INTCR = 0xC0;

  while(1) 
  {
  }
}