/* filename  FSM12.C  

   Complicated Moore FSM



   PortJ bits 7-0 are inputs, 

   PortH bits 7-0 are outputs 

   Each state can have up to 4 next state arrows

   The input to cause a state change is a sequence of 8 1,0,X

   E.g., 1X0XX1XX means Bit7=1, Bit5=0 and Bit2=1

   This pattern is encoded with AndMask=0xA4 and

                                EquMask=0x84 */

// Last modified 1/16/02 by Jonathan W. Valvano

 

// Copyright 2002 by Jonathan W. Valvano, valvano@uts.cc.utexas.edu 

//    You may use, edit, run or distribute this file 

//    as long as the above copyright notice remains 



#include "HC12.h"



// Nonvolatile structure placed in EEPROM

const struct State{

  unsigned char Out;     /* Output to Port B */

  unsigned int Wait;     /* Time (E cycles) to wait in this state */

  unsigned char AndMask[4];

  unsigned char EquMask[4];

  const struct State *Next[4];};  /* Next state if input=matches */

typedef const struct State StateType;

typedef StateType * StatePtr;



#define stop &fsm[0]

#define turn &fsm[1]

#define bend &fsm[2]

StateType fsm[3]={

{0x34, 2000,   // stop 1 ms

  {0xFF,   0xF0,   0x27,   0x00},

  {0x51,   0xA0,   0x07,   0x00},

  {turn,   stop,   turn,   bend}},

{0xB3,5000,   // turn 2.5 ms

  {0x80,   0xF0,   0x00,   0x00},

  {0x00,   0x90,   0x00,   0x00},

  {bend,   stop,   turn,   turn}},

{0x75,4000,   // bend 2 ms

  {0xFF,   0x0F,   0x01,   0x00},

  {0x12,   0x05,   0x00,   0x00},

  {stop,   stop,   turn,   stop}}};



void Init(void){

  COPCTL = 0x00;    // disable COP 

  DDRT |= 0x40;     // PortT bit 6 is output to LED

  TSCR = 0x80;      // TEN(enable)

}



void main(void){ 

StatePtr Pt; unsigned char Input; int Endt; unsigned int i;

  Init();        // disable COP, enable Port T 

  DDRH = 0xFF;   // PortH bits 7-0 are outputs

  DDRJ = 0x00;   // PortJ bits 7-0 are inputs

  PUPSJ = 0xFF;  // Pullups J7-J0

  PULEJ = 0xFF;  // Enable pull up/down PortJ

  Pt = &fsm[0];  // Initial State 

  while(1){

    PORTT ^= 0x40;            // toggle LED (debug)

    PORTH = Pt->Out;          // 1) output

    Endt = TCNT+Pt->Wait;     // Time (cycles) to wait in this state

    while(Endt-(int)TCNT>0);  // 2) wait 

    Input = PORTJ;            // 3) input 

    for(i=0;i<4;i++){

      if((Input&Pt->AndMask[i])==Pt->EquMask[i]){

	     Pt = Pt->Next[i];    // 4) next depends on input

		 i = 4; 

	  }

	}

  }

}



extern void _start();	

#pragma abs_address:0xfffe

void (*reset_vector[])() = { _start };

#pragma end_abs_address