Subversion Repositories openrisc_2011-10-31

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

// 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