GCUState.hh

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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/**
 * @file GCUState.hh
 *
 * Declaration of GCUState class.
 *
 * @author Jussi Nykänen 2004 (nykanen-no.spam-cs.tut.fi)
 * @author Pekka Jääskeläinen 2005 (pjaaskel-no.spam-cs.tut.fi)
 * @note rating: red
 */
 
#ifndef TTA_GCU_STATE_HH
#define TTA_GCU_STATE_HH
 
#include <vector>
 
#include "FUState.hh"
#include "SimValue.hh"
#include "SimulatorConstants.hh"
 
/**
 * Models the global control unit state.
 */
class GCUState : public FUState {
public:
    GCUState(
        int latency,
        int nww,
        int cuDelaySlots,
        int instructionAddressIncrement = 1);
    virtual ~GCUState();
 
    InstructionAddress& programCounter();
    SimValue& returnAddressRegister();
 
    void setProgramCounter(const InstructionAddress& value);
    void setReturnAddress(const InstructionAddress& value);
    void setReturnAddress();
 
    virtual void advanceClock();
    virtual void reset();
 
    virtual OperationContext& context();
 
private:
    /// Copying not allowed.
    GCUState(const GCUState&);
    /// Assignment not allowed.
    GCUState& operator=(const GCUState&);
    /// Natural word width as minimum addressable units.
    int naturalWordWidth_;
    /// The return address register.
    SimValue returnAddressRegister_;
    /// Program counter.
    InstructionAddress programCounter_;
    /// In case an control flow operation is pending, this variable
    /// contains the program counter value that should be updated
    /// when the control stage counter goes down.
    InstructionAddress newProgramCounter_;
    /// The delay of the control flow operations to take place.
    int latency_;
    /// The delay of branch operations in the pipeline, as opposed to this unit
    int branchDelayCycles_;
    /// If this this is true, there's a control flow operation pending.
    bool operationPending_;
    /// This indicates how many cycles the operation has been pending,
    /// when this reaches the latency, the PC is updated with the
    /// new value.
    int operationPendingTime_;
    /// The operation context for this FU.
    OperationContext operationContext_;
    /// The increment to instruction address to retrieve next instruction.
    int instructionAddressIncrement_ = 1;
};
 
#include "GCUState.icc"
 
#endif