示例#1
0
        //Method:       Fetch
        //Purpose:      Reads next word to execute, increments program counter.
        public uint Fetch()
        {
            //retrive command pointed to by addr stored in register 15
            uint command = myRegisters.ReadWord(15);

            return(myMemory.ReadWord(command - 8));
            //read word from RAM address specified by program counter register
            //(program counter register is 15)
        }
示例#2
0
        public uint getValue()
        {
            if (Instructions.getSectionValue(25, 25, instruction) == 1)
            {
                if (Instructions.getSectionValue(11, 8, instruction) == 0)
                {
                    In_DataProcessing.opTwoDissasembly = '#' + Convert.ToString(Instructions.getSectionValue(7, 0, instruction));
                }
                type = 3;
                In_DataProcessing.opTwoDissasembly = '#' + Convert.ToString((Instructions.getSectionValue(7, 0, instruction) >> (int)(2 * Instructions.getSectionValue(11, 8, instruction))) | (Instructions.getSectionValue(7, 0, instruction) << (32 - (int)(2 * Instructions.getSectionValue(11, 8, instruction)))));
                return((Instructions.getSectionValue(7, 0, instruction) >> (int)(2 * Instructions.getSectionValue(11, 8, instruction))) | (Instructions.getSectionValue(7, 0, instruction) << (32 - (int)(2 * Instructions.getSectionValue(11, 8, instruction)))));
            }

            rm    = Instructions.getSectionValue(3, 0, instruction);
            shift = Instructions.getSectionValue(6, 5, instruction);


            //this instruction will be shifting rn by something
            if (rm == 15)
            {
                In_DataProcessing.opTwoDissasembly = "pc";
            }
            else
            {
                In_DataProcessing.opTwoDissasembly = 'r' + Convert.ToString(rm);
            }


            if (Instructions.getSectionValue(4, 4, instruction) == 1)
            {
                type        = 2;
                shiftAmt    = myRegisters.ReadWord(Instructions.getSectionValue(11, 8, instruction));
                strShiftAmt = 'r' + Convert.ToString(Instructions.getSectionValue(11, 8, instruction));
                return(getShiftDone()); //calculate shift
            }
            else
            {
                type        = 1;
                shiftAmt    = Instructions.getSectionValue(11, 7, instruction);
                strShiftAmt = '#' + Convert.ToString(Instructions.getSectionValue(11, 7, instruction));
                return(getShiftDone()); //calculate shift
            }
        }
示例#3
0
        public override void execute()
        {
            //switch statement to determine WHICH execute command to do.
            switch (opcode)
            {
            case 1:
                //to string
                disassembly = "bx" + Instructions.firstOpcode + (myRegister.ReadWord(getSectionValue(3, 0, instruction)));
                if (!disassembling)
                {
                    executeBX();
                }
                break;

            case 10:
                //to string
                disassembly = "b" + Instructions.firstOpcode + " " + (myRegister.ReadWord(15) + targetAddr);
                if (!disassembling)
                {
                    executeB();
                }
                break;

            case 11:
                //to string
                disassembly = "bl" + Instructions.firstOpcode + " " + (myRegister.ReadWord(15) + targetAddr);
                if (!disassembling)
                {
                    executeBL();
                }
                break;

            default:
                break;
            }
        }
示例#4
0
        public uint getShiftDone()
        {
            rm = myRegisters.ReadWord(rm);
            switch (shift)
            {
            case 0:
                //LSL
                if (shiftAmt != 0)
                {
                    In_LoadStore.opTwoDissasembly += ", lsl " + strShiftAmt;
                }
                return(rm << (int)shiftAmt);

            case 1:
                //LSR
                if (shiftAmt != 0)
                {
                    In_LoadStore.opTwoDissasembly += ", lsr " + strShiftAmt;
                }
                return(rm >> (int)shiftAmt);

            case 2:
                //ASR
                //CAST TO INT (logic shift becomes arithmaic)
                if (shiftAmt != 0)
                {
                    In_LoadStore.opTwoDissasembly += ", asr " + strShiftAmt;
                }
                return((uint)((int)rm >> (int)shiftAmt));

            default:
                //ROR
                In_LoadStore.opTwoDissasembly += ", ror " + strShiftAmt;
                return((rm >> (int)shiftAmt) | (rm << (int)(32 - shiftAmt)));
            }
        }
示例#5
0
文件: Computer.cs 项目: wiglz4/ARMsim
        //Method:       Run
        //Purpose:      Runs through entire simulated program using CPU fetch-decode-execute.
        public void Run()
        {
            uint curCommand = myCPU.Fetch();

            while (curCommand != 0 && !abort)
            {
                storedBranchPC = 0;
                stepNum++;
                //used for debugging stuffs
                //check stepnum OR pc counter

                /* if (stepNum == 2396)
                 * {
                 *  string x;
                 * }*/
                if (myCPU.Decode(curCommand))
                {
                    if (Instructions.dontDoItBro == false)
                    {
                        myCPU.Execute();

                        //check to see if we wrote word to 100000
                        if (myRam.output)
                        {
                            //prompt user for input
                            //call event handler to update screen

                            if (outputQ.Count == 0)
                            {
                                output = '0';
                            }
                            else
                            {
                                output = outputQ.Dequeue();
                            }
                            myRam.output = false;
                            putChar(this, e);
                        }
                    }
                    else
                    {
                        myRegisters.IncrCounter();
                    }
                    curCommand = myCPU.Fetch();
                    if (trace)
                    {
                        if (storedBranchPC == 0)
                        {
                            WriteTrace((int)myRegisters.ReadWord(15) - 12);
                        }
                        else
                        {
                            WriteTrace(storedBranchPC);
                        }
                    }
                }
                else
                {
                    if (trace)
                    {
                        WriteTrace((int)myRegisters.ReadWord(15) - 8);
                    }
                    curCommand = 0;
                }
            }
            endRun(this, e);
        }
示例#6
0
 public void executeMUL()
 {
     myRegister.WriteWord(rd, (myRegister.ReadWord(rs) * myRegister.ReadWord(rm)));
 }
示例#7
0
        public void executeLDR()
        {
            int operand2int = Convert.ToInt32(operand2);

            if (u == 0)
            {
                operand2int *= -1;
            }
            //gettin rn
            if (p == 1)
            {
                addr = (uint)(myRegister.ReadWord(rn) + operand2int);
            }
            else if (p == 0)
            {
                addr = myRegister.ReadWord(rn);
            }
            //performing the load
            if (bs == 0)
            {
                if (!disassembling)
                {
                    myRegister.WriteWord(rd, myMemory.ReadWord(addr));
                }
                disassembly = "ldr" + Instructions.firstOpcode + " ";
            }
            else if (bs == 1)
            {
                if (!disassembling)
                {
                    myRegister.WriteWord(rd, myMemory.ReadByte(addr));
                }
                disassembly = "ldrb" + Instructions.firstOpcode + " ";
            }

            disassembly += "r" + Convert.ToString(rd);

            //writeback?
            if (p == 1 && w == 1)
            {
                if (!disassembling)
                {
                    myRegister.WriteWord(rn, addr);
                }
                disassembly += "!";
            }

            disassembly += ", [r" + Convert.ToString(rn) + opTwoDissasembly + "]";
        }
示例#8
0
 public void executeADD()
 {
     myRegister.WriteWord(rd, (myRegister.ReadWord(rn) + operand2));
 }