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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