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// ----------------------------------------------------------------------------
 
// TAP IR-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_IR_SCAN__H
#define TAP_ACTION_IR_SCAN__H
 
#include <stdint.h>
 
#include "TapAction.h"
#include "TapStateMachine.h"
 
 
//! Class to represent a TAP IR-Scan action.
 
//! This class assumes that JTAG instruction registers are relatively
//! small. IEEE 1149.1 mandates at least 2 bits, although implementations
//! often have a wider range of instructions. The OpenRISC 1000 debug unit for
//! example uses 5 bits. 32-bits seems more than enough for the largest
//! applications.
 
class TapActionIRScan
  : public TapAction
{
public:
 
  // Constructor
  TapActionIRScan (sc_core::sc_event *_doneEvent,
		   uint32_t           _iRegIn,
		   int                _iRegSize);
 
  // Get the shifted out value
  uint32_t  getIRegOut ();
 
 
protected:
 
  // Process the action for IR-Scan
  bool  process (TapStateMachine *tapStateMachine,
		 bool            &tdi,
		 bool             tdo,
		 bool            &tms);
 
 
private:
 
  //! The value being shifted in
  uint32_t  iRegIn;
 
  //! The number of bits to shift
  int       iRegSize;
 
  //! The value shifted out
  uint32_t  iRegOut;
 
  //! The number of bits shifted so far
  int       bitsShifted;
 
  //! Where we are in the IR-scan process
  enum {
    SHIFT_IR_PREPARING,
    SHIFT_IR_SHIFTING,
    SHIFT_IR_UPDATING
  } iRScanState;
 
};	// TapActionIRScan
 
#endif	// TAP_ACTION_IR_SCAN__H