/* Moore FSM   filename  MOORE11.C
   Simulator program of a Moore Finite State Machine

   This example accompanies the book
      "Embedded Microcomputer Systems: Real Time Interfacing", Brooks-Cole, copyright (c) 2000,
      Jonathan W. Valvano 7/6/99

   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
*/

/* PortC bits 1-0 are inputs, 
   PortB bits 7-0 are outputs 
   Each state has
     a function to execute
     a time to wait and
     4 next state arrows
*/
#include "HC11.h"
const struct State{
    void (*CmdPt)(void);   /* function to execute */
    unsigned int Time;     /* Time (cycles) to wait in this state */
    const struct State *Next[4];};  /* Next state if input=0,1,2,3 */
typedef const struct State StateType;
typedef StateType * StatePtr;
void DoStop(void){  PORTB=0x34;}
void DoTurn(void){  PORTB=0xB3;}
void DoBend(void){  PORTB=0x75;}
#define stop &fsm[0]
#define turn &fsm[1]
#define bend &fsm[2]
StateType fsm[3]={
{&DoStop, 200, {turn, stop, turn, bend}},  /* Stop state */
{&DoTurn, 500, {bend, stop, turn, turn}},  /* Turn state */
{&DoBend, 400, {stop, stop, turn, stop}}}; /* Bend state */
StatePtr Pt; unsigned char Input; 
void Wait(unsigned int delay){ int Endt;
    Endt=TCNT+delay;        /* Time (500ns cycles) to wait */
    while((Endt-(int)TCNT)>0);   /* wait */
};
void main(void){   
/* PortB bits 7-0 are outputs */
  DDRC=0x00;     /* PortC bits 1-0 are inputs */
  Pt=stop;       /* Initial State  */
  while(1){
    (*Pt->CmdPt)();           /* 1) execute function */
    Wait(Pt->Time);           /* 2) Time (cycles) to wait in this state */
    Input=(PORTC)&0x03;       /* 3) input */ 
    Pt=Pt->Next[Input];       /* 4) next depends on input */
  }
};

void resetVectors(void){
/* not really a function, 
   but this must be last */
  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  */
}