Subversion Repositories openrisc_me

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

// TAP action header: abstract class implementation

// 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.

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

// $Id$

#include <iostream>

#include "TapAction.h"

class  sc_event;

//! Constructor

//! Records the SystemC event used to notify completion and sets the

//! resetCounter to zero.

//! @param _actionType  The action type

TapAction::TapAction (sc_core::sc_event *_doneEvent) :

  doneEvent (_doneEvent),

  resetCounter (0)

{

}       // TapAction ()

//! Accessor to get the SystemC completion event

//! @return  The SystemC completion event

sc_core::sc_event *

TapAction::getDoneEvent ()

{

  return  doneEvent;

}       // getDoneEvent ()

//! Function to check the TAP is in a consistent state, optionally with a

//! warning.

//! This is a convenience for subclasses (hence protected), so they can ensure

//! the state machine is in a consistent state.

//! @note The method returns TRUE to indicate that the machine is in the

//!       consistent state. However the TapStateMachine resetDone flag is set

//!       when the final TMS is set - the state will only be reached IF that

//!       TMS is driven. This mechanism gives users flexibility. They can

//!       detect the final TMS being driven.

//! @param[in]  tapStateMachine  The TAP state machine with which we are

//!                              associated.

//! @param[out] tms              The value to drive on the JTAG TMS

//! @param[in]  warn             True to indicate a warning message should be

//!                              issued when starting a reset cycle.

//! @return  TRUE if the TAP state machine was already in a consistent state.

bool

TapAction::checkResetDone (TapStateMachine *tapStateMachine,

                           bool            &tms,

                           bool             warn)

{

  // Nothing more to do if we are consistent

  if (tapStateMachine->getResetDone ())

    {

      return  true;

    }

  // Need to reset. If requested and this is the first cycle of reset, give a

  // warning.

  if (warn && (0 == resetCounter))

    {

      std::cerr << "JTAG TAP state inconsistent: resetting" << std::endl;

    }

  // Drive towards reset

  resetCounter++;

  tms = 1;

  // If we have got to the end of the reset sequence we can clear the

  // tapStateMachine and report we are consistent. However we will not return

  // true until the next call.

  if (tapStateMachine->TAP_RESET_CYCLES == resetCounter)

    {

      tapStateMachine->setResetDone (true);

      resetCounter = 0;                          // Ready for next time

    }

  else

    {

      return false;

    }

}       // checkResetDone ()