Arch.SM213.Machine.Student
Class CPU

java.lang.Object
  java.util.Observable
      Machine.AbstractCPU
          Arch.SM213.Machine.AbstractSM213CPU
              Arch.SM213.Machine.Student.CPU

public class CPU
extends AbstractSM213CPU

The Simple Machine CPU. Simulate the execution of a single cycle of the Simple Machine CPU.

See Also:

AbstractSM213CPU

Nested Class Summary

Nested classes/interfaces inherited from class Machine.AbstractCPU

AbstractCPU.InvalidInstructionException, AbstractCPU.MachineHaltException

Field Summary

Fields inherited from class Arch.SM213.Machine.AbstractSM213CPU

curInst, insOp0, insOp1, insOp2, insOpCode, insOpExt, insOpImm, instruction, pc, ps

Fields inherited from class Machine.AbstractCPU

CURRENT_INSTRUCTION_ADDRESS, isInterrupt, mem, PC, processorState, reg

Constructor Summary

CPU(MainMemory aMem)

Method Summary

protected void	execute() Execution Stage of CPU Cucle.
protected void	fetch() Fetch Stage of CPU Cycle.

Methods inherited from class Arch.SM213.Machine.AbstractSM213CPU

cycle, setPC

Methods inherited from class Machine.AbstractCPU

getMainMemory, getName, getPC, getProcessorState, getRegisterFile, start, triggerInterrupt

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CPU

public CPU(MainMemory aMem)

Method Detail

fetch

protected void fetch()
              throws AbstractMainMemory.InvalidAddressException

Fetch Stage of CPU Cycle. Fetch instruction at address stored in "pc" register from memory into instruction register and set "pc" to point to the next instruction to execute. Input register: pc. Output registers: pc, instruction, insOpCode, insOp0, insOp1, insOp2, insOpImm, insOpExt

Specified by:

fetch in class AbstractSM213CPU

Throws:

MainMemory.InvalidAddressException - when program counter contains an invalid memory address

AbstractMainMemory.InvalidAddressException

See Also:

for pc, instruction, insOpCode, insOp0, insOp1, insOp2, insOpImm, insOpExt

execute

protected void execute()
                throws AbstractCPU.InvalidInstructionException,
                       AbstractCPU.MachineHaltException,
                       RegisterSet.InvalidRegisterNumberException,
                       AbstractMainMemory.InvalidAddressException

Execution Stage of CPU Cucle. Execute instruction that was fetched by Fetch stage. Input state: pc, instruction, insOpCode, insOp0, insOp1, insOp2, insOpImm, insOpExt, reg, mem Ouput state: pc, reg, mem

Specified by:

execute in class AbstractSM213CPU

Throws:

InvalidInstructionException - when instruction format is invalid

MachineHaltException - when instruction is the HALT instruction

RegisterSet.InvalidRegisterNumberException - when instruction references an invalid register (i.e, not 0-7)

MainMemory.InvalidAddressException - when instruction references an invalid memory address

AbstractCPU.InvalidInstructionException

AbstractCPU.MachineHaltException

AbstractMainMemory.InvalidAddressException

See Also:

for pc, instruction, insOpCode, insOp0, insOp1, insOp2, insOpImm, insOpExt, for mem, for reg