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/*
* Copyright (c) 2002-2010 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
* General Public License as published by the Free Software
* Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
# include "config.h"
# include "functor.h"
# include "netlist.h"
# include <cassert>
bool NetAssign::is_asynchronous()
{
return true;
}
bool NetCondit::is_asynchronous()
{
return false;
}
/*
* NetEvWait statements come from statements of the form @(...) in the
* Verilog source. These event waits are considered asynchronous if
* all of the events in the list are ANYEDGE, and all the inputs to
* the statement are included in the sensitivity list. If any of the
* events are posedge or negedge, the statement is synchronous
* (i.e. an edge-triggered flip-flop) and if any of the inputs are
* unaccounted for in the sensitivity list then the statement is a
* latch.
*/
bool NetEvWait::is_asynchronous()
{
/* The "sense" set contains the set of Nexa that are in the
sensitivity list. We also require that the events are all
level sensitive, but the nex_async_ method takes care of
that test. */
NexusSet*sense = new NexusSet;
for (unsigned idx = 0 ; idx < events_.size() ; idx += 1) {
NexusSet*tmp = events_[idx]->nex_async_();
if (tmp == 0) {
delete sense;
return false;
}
sense->add(*tmp);
delete tmp;
}
NexusSet*inputs = statement_->nex_input();
if (! sense->contains(*inputs)) {
delete sense;
delete inputs;
return false;
}
delete sense;
delete inputs;
/* If it passes all the other tests, then this statement is
asynchronous. */
return true;
}
bool NetProc::is_asynchronous()
{
return false;
}
bool NetProcTop::is_asynchronous() const
{
if (type_ == IVL_PR_INITIAL)
return false;
return statement_->is_asynchronous();
}
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