sc_signal_resolved.cpp

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  set forth in the SystemC Open Source License Version 2.4 (the "License");
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/*****************************************************************************

  sc_signal_resolved.cpp -- The resolved signal class.

  Original Author: Martin Janssen, Synopsys, Inc., 2001-05-21

 *****************************************************************************/

/*****************************************************************************

  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
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// $Log: sc_signal_resolved.cpp,v $
// Revision 1.1.1.1  2006/12/15 20:31:35  acg
// SystemC 2.2
//
// Revision 1.4  2006/03/21 00:00:27  acg
//   Andy Goodrich: changed name of sc_get_current_process_base() to be
//   sc_get_current_process_b() since its returning an sc_process_b instance.
//
// Revision 1.3  2006/01/13 18:47:42  acg
// Added $Log command so that CVS comments are reproduced in the source.
//

#include "sysc/communication/sc_signal_resolved.h"

namespace sc_core {

// Note that we assume that two drivers driving the resolved signal to a 1 or
// 0 is O.K. This might not be true for all technologies, but is certainly
// true for CMOS, the predominant technology in use today.

const sc_dt::sc_logic_value_t
sc_logic_resolution_tbl[4][4] =
{   //    0      1      Z      X
    { sc_dt::Log_0, sc_dt::Log_X, sc_dt::Log_0, sc_dt::Log_X }, // 0
    { sc_dt::Log_X, sc_dt::Log_1, sc_dt::Log_1, sc_dt::Log_X }, // 1
    { sc_dt::Log_0, sc_dt::Log_1, sc_dt::Log_Z, sc_dt::Log_X }, // Z
    { sc_dt::Log_X, sc_dt::Log_X, sc_dt::Log_X, sc_dt::Log_X }  // X
};


// ----------------------------------------------------------------------------
//  CLASS : sc_logic_resolve
//
//  Resolution function for sc_dt::sc_logic.
// ----------------------------------------------------------------------------

// resolves sc_dt::sc_logic values and returns the resolved value

void
sc_logic_resolve::resolve( sc_dt::sc_logic& result_,
               const std::vector<sc_dt::sc_logic*>& values_ )
{
    int sz = values_.size();

    assert( sz != 0 );

    if( sz == 1 ) {
    result_ = *values_[0];
    return;
    }

    sc_dt::sc_logic_value_t res = values_[0]->value();
    for( int i = sz - 1; i > 0 && res != 3; -- i ) {
    res = sc_logic_resolution_tbl[res][values_[i]->value()];
    }
    result_ = res;
}


// ----------------------------------------------------------------------------
//  CLASS : sc_signal_resolved
//
//  The resolved signal class.
// ----------------------------------------------------------------------------

// destructor

sc_signal_resolved::~sc_signal_resolved()
{
    for( int i = m_val_vec.size() - 1; i >= 0; -- i ) {
    delete m_val_vec[i];
    }
}


// write the new value

void
sc_signal_resolved::write( const data_type& value_ )
{
    sc_process_b* cur_proc = sc_get_current_process_b();

    bool value_changed = false;
    bool found = false;
    
    for( int i = m_proc_vec.size() - 1; i >= 0; -- i ) {
    if( cur_proc == m_proc_vec[i] ) {
        if( value_ != *m_val_vec[i] ) {
        *m_val_vec[i] = value_;
        value_changed = true;
        }
        found = true;
        break;
    }
    }
    
    if( ! found ) {
    m_proc_vec.push_back( cur_proc );
    m_val_vec.push_back( new data_type( value_ ) );
    value_changed = true;
    }
    
    if( value_changed ) {
    request_update();
    }
}


void
sc_signal_resolved::update()
{
    sc_logic_resolve::resolve( m_new_val, m_val_vec );
    base_type::update();
}


} // namespace sc_core

// Taf!

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