示例#1
0
        public Instruction Create(uint data)
        {
            byte operationType = Instruction.GetOperationType(data);
            bool bit4          = Memory.TestFlagInData(data, 4);

            switch (operationType)
            {
            case 0x0:                                                                                       // 000
                if (Memory.ExtractBits(data, 21, 24) == 0 && (Memory.ExtractBits(data, 4, 7) >> 4) == 0x09) // instruction is a MUL
                {
                    Data dInstr = new Data(data);
                    dInstr.DataMul();
                    dInstr.ExecuteInstruction(true);
                    return(dInstr);
                }
                else if (bit4 == false)     // Data Register, Immediate-shifted Register
                {
                    Data dInstr = new Data(data);
                    dInstr.DataRegImmShiftedReg();
                    dInstr.ExecuteInstruction(true);
                    return(dInstr);
                }
                else if (bit4 == true && Memory.ExtractBits(data, 20, 24) >> 20 == 0x12)     // BX instruction
                {
                    Branch bInstr = new Branch(data);
                    bInstr.Branch();
                    bInstr.ExecuteInstruction(true);
                    return(bInstr);
                }
                else     // Data Register-shifted Immediate
                {
                    Data dInstr = new Data(data);
                    dInstr.DataRegShiftedReg();
                    dInstr.ExecuteInstruction(true);
                    return(dInstr);
                }

            case 0x1:     // 001 - Data Immediate
                Data dataInstr = new Data(data);
                dataInstr.DataImmediate();
                dataInstr.ExecuteInstruction(true);     // generate disassembly
                return(dataInstr);

            case 0x2:     // 010 - Load/Store Immediate
                LdStore ldstrInstr = new LdStore(data);
                ldstrInstr.LdStrImmediate();
                ldstrInstr.ExecuteInstruction(true);
                return(ldstrInstr);

            case 0x3:     // 011 - Load/Store Immediate-shifted Register
                LdStore ldstInstr = new LdStore(data);
                ldstInstr.LdStrImmShiftedReg();
                ldstInstr.ExecuteInstruction(true);
                return(ldstInstr);

            case 0x4:     // 100 - Load/Store Multiple
                LoadStoreMultiple ldstrMul = new LoadStoreMultiple(data);
                ldstrMul.LdStrMultiple();
                ldstrMul.ExecuteInstruction(true);
                return(ldstrMul);

            case 0x5:     // 101 - Branch
                Branch b = new Branch(data);
                b.Branch();
                b.ExecuteInstruction(true);
                return(b);

            case 0x07:     // 111 - SWI
                SWI swiInstr = new SWI(data);
                swiInstr.LoadDataSWI();
                swiInstr.ExecuteInstruction(true);
                return(swiInstr);

            default:
                // an unsupported instruction was provided
                Instruction i = new Instruction();
                return(i);
            }
        }