// filename  Interp12.C  

// Linked List Interpreter

// Last modified 12/12/02 by Jonathan W. Valvano

 

// Copyright 2003 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"

#include "SCI12.H"



const struct Node{

  unsigned char Letter;     // type this letter

  void (*fnctPt)(void);     // to execute this command

  const struct Node *Next;};  

typedef const struct Node NodeType;

typedef NodeType * NodePtr;



//*****************OutCRLF***************

// Output a CR,LF to go to a new line

void OutCRLF(void){

  SCI_OutChar(CR);

  SCI_OutChar(LF);

}



//******** CommandA *************** 

// output a simple message

void CommandA(void){

  OutCRLF();

  SCI_OutString("Executing Command a"); 

}



//******** CommandB *************** 

// output a simple message

void CommandB(void){

  OutCRLF();

  SCI_OutString("Executing Command b"); 

}



//******** CommandC *************** 

// output a simple message

void CommandC(void){

  OutCRLF();

  SCI_OutString("Executing Command c"); 

}



//******** Help *************** 

// explain how to use this system

void Help(void){

  OutCRLF();

  SCI_OutString("a executes Command a");

  OutCRLF();

  SCI_OutString("b executes Command b");

  OutCRLF();

  SCI_OutString("c executes Command c");

}



NodeType LL[4]={ // linear linked list

{ 'a', &CommandA, &LL[1]},

{ 'b', &CommandB, &LL[2]},

{ 'c', &CommandC, &LL[3]},

{ '?', &Help, 0 }};



//******** InitTimer *************** 

// Turn off COP, enable timer, PT6 is output

void InitTimer(void){

  COPCTL = 0x00;    // disable COP 

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

  TSCR = 0x80;      // TEN(enable)

}



void main(void){ NodePtr pt; char string[40];

  SCI_Init(13);

  InitTimer();     // initialize COP, Port T 



  OutCRLF();

  SCI_OutString("Interpreter example  12/12/02 -JWV");

  Help();

  OutCRLF();

  SCI_OutString("Enter a single letter command followed by <enter>"); 

  while(1){

    PORTT ^= 0x40;   // toggle LED

    OutCRLF();

    SCI_OutString(">"); 

    SCI_InString(string,39);

    pt = &LL[0];           // first node to check

    while(pt){

      if(string[0]==pt->Letter){

        pt->fnctPt();

        break;

      }

      else {

        pt = pt->Next;

        if(pt==0){ 

          SCI_OutString(" Error");

        }

      }

    }

  }

}

#include "SCI12.C"



extern void _start();	

#pragma abs_address:0xfffe

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

#pragma end_abs_address