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// ----------------------------------------------------------------------------

// TAP DR-Scan action: definition

// Copyright (C) 2009  Embecosm Limited <info@embecosm.com>

// Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>

// This file is part of the Embecosm cycle accurate SystemC JTAG library.

// This program is free software: you can redistribute it and/or modify it

// under the terms of the GNU Lesser General Public License as published by

// the Free Software Foundation, either version 3 of the License, or (at your

// option) any later version.

// This program is distributed in the hope that it will be useful, but WITHOUT

// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public

// License for more details.

// You should have received a copy of the GNU Lesser General Public License

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// The C/C++ parts of this program are commented throughout in a fashion

// suitable for processing with Doxygen.

// ----------------------------------------------------------------------------

// $Id$

#ifndef TAP_ACTION_DR_SCAN__H

#define TAP_ACTION_DR_SCAN__H

#include <stdint.h>

#include "TapAction.h"

#include "TapStateMachine.h"

//! Class to represent a TAP DR-Scan action.

//! JTAG data registers can be huge and are represented generically as arrays

//! of uint64_t. However for efficiency versions of methods are provided based

//! on a single uint64_t.

//! The SystemC classes for large unsigned ints are fabulously inefficient in

//! the reference implementation, so are not used here.

class TapActionDRScan:public TapAction {

public:

        // Constructors and destructor

        TapActionDRScan(sc_core::sc_event * _doneEvent,

                        uint64_t _dRegInArray[], int _dRegSize);

         TapActionDRScan(sc_core::sc_event * _doneEvent,

                         uint64_t _dRegIn, int _dRegSize);

         TapActionDRScan(sc_core::sc_event * _doneEvent,

                         uint64_t _dRegInArray[],

                         int _dRegSize,

                         int _goToPauseState, int _bitsBeforePauseState);

         TapActionDRScan(sc_core::sc_event * _doneEvent,

                         uint64_t _dRegIn,

                         int _dRegSize,

                         int _goToPauseState, int _bitsBeforePauseState);

        ~TapActionDRScan();

        // Get the shifted out value

        void getDRegOut(uint64_t dRegArray[]);

        uint64_t getDRegOut();

protected:

        // Process the action for IR-Scan

         bool process(TapStateMachine * tapStateMachine,

                      bool & tdi, bool tdo, bool & tms);

private:

        //! Number of bits in the data register

        int dRegBitSize;

        //! Number of uint64_t words in the data register

        int dRegWordSize;

        //! Mask for top word in multi-word register

        uint64_t topMask;

        //! The value being shifted in

        uint64_t *dRegInArray;

        //! The value being shifted in (small version optimization)

        uint64_t dRegIn;

        //! The value shifted out

        uint64_t *dRegOutArray;

        //! The value being shifted out (small version optimization)

        uint64_t dRegOut;

        //! Should we go to PAUSE state and poll tdo during operation?

        int goToPauseState;

        //! Number of bits to shift before going to PAUSE state and polling tdo

        int bitsBeforePause;

        int pauseStateCount;

        //! Bits shifted so far

        int bitsShifted;

        //! Where we are in the Shift-DR process

        enum {

                SHIFT_DR_PREPARING,

                SHIFT_DR_SHIFTING,

                SHIFT_DR_SHIFTING_BEFORE_PAUSE,

                SHIFT_DR_SHIFTING_PAUSE,

                SHIFT_DR_EXIT2,

                SHIFT_DR_SHIFTING_AFTER_PAUSE,

                SHIFT_DR_UPDATING

        } dRScanState;

        // Utilities to shift the bottom bit out and top bit in

        bool shiftDRegOut();

        void shiftDRegIn(bool bitIn);

};                              // TapActionDRScan

#endif // TAP_ACTION_DR_SCAN__H