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/*
* Copyright (c) 1999 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT) && !defined(macintosh)
#ident "$Id: PDelays.cc,v 1.4 2001/01/20 02:15:50 steve Exp $"
#endif
# include "PDelays.h"
# include "PExpr.h"
# include "verinum.h"
PDelays::PDelays()
{
for (unsigned idx = 0 ; idx < 3 ; idx += 1)
delay_[idx] = 0;
}
PDelays::~PDelays()
{
for (unsigned idx = 0 ; idx < 3 ; idx += 1)
delete delay_[idx];
}
void PDelays::set_delay(PExpr*del)
{
assert(del);
assert(delay_[0] == 0);
delay_[0] = del;
}
void PDelays::set_delays(const svector<PExpr*>*del)
{
assert(del);
assert(del->count() <= 3);
for (unsigned idx = 0 ; idx < del->count() ; idx += 1)
delay_[idx] = (*del)[idx];
}
static unsigned long calculate_val(Design*des, const NetScope*scope,
const PExpr*expr)
{
assert(expr);
unsigned long val;
int shift = scope->time_unit() - des->get_precision();
if (verireal*dr = expr->eval_rconst(des, scope)) {
val = dr->as_long(shift);
delete dr;
} else {
verinum*dv = expr->eval_const(des, scope->name());
if (dv == 0) {
cerr << expr->get_line() << ": sorry: non-constant "
<< "delays not supported here: " << *expr << endl;
des->errors += 1;
return 0;
}
assert(dv);
val = dv->as_ulong();
val = des->scale_to_precision(val, scope);
delete dv;
}
return val;
}
void PDelays::eval_delays(Design*des, const string&path,
unsigned long&rise_time,
unsigned long&fall_time,
unsigned long&decay_time) const
{
NetScope*scope = des->find_scope(path);
assert(scope);
int shift = scope->time_unit() - des->get_precision();
if (delay_[0]) {
rise_time = calculate_val(des, scope, delay_[0]);
if (delay_[1]) {
fall_time = calculate_val(des, scope, delay_[1]);
if (delay_[2]) {
decay_time = calculate_val(des, scope, delay_[2]);
} else {
if (rise_time < fall_time)
decay_time = rise_time;
else
decay_time = fall_time;
}
} else {
assert(delay_[2] == 0);
fall_time = rise_time;
decay_time = rise_time;
}
} else {
rise_time = 0;
fall_time = 0;
decay_time = 0;
}
}
/*
* $Log: PDelays.cc,v $
* Revision 1.4 2001/01/20 02:15:50 steve
* apologize for not supporting non-constant delays.
*
* Revision 1.3 2001/01/14 23:04:55 steve
* Generalize the evaluation of floating point delays, and
* get it working with delay assignment statements.
*
* Allow parameters to be referenced by hierarchical name.
*
* Revision 1.2 2000/02/23 02:56:53 steve
* Macintosh compilers do not support ident.
*
* Revision 1.1 1999/09/04 19:11:46 steve
* Add support for delayed non-blocking assignments.
*
*/
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