VirtualMachine.h

/******************************************************************************
Filename: VirtualMachine.h
By: Matthew DeBord and Ronald Radut
Created: 04/11/2011
Last Modified: 04/20/2011
Description: This header contains class declarations for the Virtual Machine
******************************************************************************/


#include <cstdlib>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <sstream>
using namespace std;

// following format classes property of K Zemoudeh
class format1 {
    public:
        unsigned UNUSED:6;
        unsigned RS:2;
        unsigned I:1;
        unsigned RD:2;
        unsigned OP:5;
    };
class format2 {
    public:
        unsigned ADDR:8;
        unsigned I:1;
        unsigned RD:2;
        unsigned OP:5;
    };
class format3 {
    public:
        int CONST:8;
        unsigned I:1;
        unsigned RD:2;
        unsigned OP:5;
    };
union instruction {
        int i;
        format1 f1;
        format2 f2;
        format3 f3;
    };

// Begin Virtual Machine Class
class VirtualMachine
{
            private:
                static const int REG_FILE_SIZE = 4;
                static const int MEM_SIZE = 256;
                vector<int> r;
                vector<int> mem;
                string line;
                unsigned int ir, pc, sr, sp, clock, base, limit;

                //sign extender
                int signExtend(int i);

                // following functions set the corresponding bit for the sr
                void setV(int i);
                void setL(int i);
                void setE(int i);
                void setG(int i);
                void setC(int i);

                //following functions GET the corresponding bit from sr
                int getV();
                int getL();
                int getE();
                int getG();
                int getC();

                bool checkOverflow(int a, int b);
                bool checkOverflow3(int a, int b, int c);
                bool checkOverflow1(int a);
                // need base/limit registers??  <--- ATTN <----

           public:
               VirtualMachine();
               void Execute();

};