/* filename ********** tof.c *****************
   Simulator tutorial program showing timer overflow interrupts

   This example accompanies the book
     "Embedded Microcomputer Systems: Real Time Interfacing", Brooks-Cole, copyright (c) 2000,
      Jonathan W. Valvano 7/16/99

   Interface between the TExaS simulator running a MC68HC11 EVB
      with ICC11 freeware compiler 
   TExaS Copyright 1999 by Jonathan W. Valvano 
   for more information about ICC11 
      see http://www.imagecraft.com
   You may use this file without restrictions */

#include "HC11.h"

/* counts the number of TOF interrupts */
unsigned int time;

void main(void){ 
  time=0;
  TMSK2=0x80;   /* arm TOF */
  TFLG2=0x80;   /* initially clear TOF */
asm(" cli");    /* enable interrupts */  
  while(1){}
}
/* ----------called when TCNT=0--------- */
void TOFhndlr(void){
  time++;
  PORTB ^= 0x40;    /* toggle PB6 */
  TFLG2 =  0x80;    /* acknowledge TOF */
asm(" rti");
}
/* 6811 interrupts supported by TExaS
  $FFFE	Reset
  $FFFC	COP Clock Monitor Fail (not supported)
  $FFFA	COP Failure Reset (not supported)
  $FFF8	Unimplemented Instruction Trap 	 (not supported)
  $FFF6	SWI 
  $FFF4	XIRQ  (not supported) 
  $FFF2	IRQ or STRA (IRQ not supported, STRA is supported)
  $FFF0	Real Time Interrupt (not supported) 
  $FFEE	Timer input capture 1	 
  $FFEC	Timer input capture 2	
  $FFEA	Timer input capture 3	
  $FFE8	Timer output compare 1	
  $FFE6	Timer output compare 2	
  $FFE4	Timer output compare 3
  $FFE2	Timer output compare 4	
  $FFE0	Timer output compare 5	
  $FFDE 	Timer Overflow 
  $FFDC 	Pulse Accumulator Overflow (not supported) 
  $FFDA 	Pulse Accumulator Input Edge  (not supported)
  $FFD8 	SPI Serial Transfer Complete  (not supported) 
  $FFD6 	SCI Transmit Buffer Empty
               SCI Transmit Complete (not supported)
               SCI Receiver Buffer Full */
void resetVectors(void){
/* not really a function, 
   but this must be last */
  asm(" org $FFDE");
  asm(" FDB _TOFhndlr");
  asm(" org $FFFE");
  asm(" FDB __start");
  asm(" org $FC00"); /* puts rts in a harmless place */
/* string constants also placed here */
/* the value FC00 means you can have up to 1000 characters of strings  */
}