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propinit.cc
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propinit.cc
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/*
* Copyright (c) 1998 Stephen Williams (steve@picturel.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)
#ident "$Id: propinit.cc,v 1.1 1998/12/20 02:05:41 steve Exp $"
#endif
/*
* The propinit function runs through the devices that can impose
* initial values in the netlist and propogates those values. The
* process works by first scanning the active devices for outputs that
* they generate.
*/
# include "netlist.h"
/*
* prop_sequdp_output takes the output from the located sequential UDP
* device and propogates it to the signals connected to it.
*/
static bool is_sequ_udp(const NetNode*net)
{
const NetUDP*udp;
if ((udp = dynamic_cast<const NetUDP*>(net)) == 0)
return false;
return udp->is_sequential();
}
static void prop_sequdp_output(NetUDP*udp)
{
/* Get from the UDP class the initial output value. */
verinum::V ival;
switch (udp->get_initial()) {
case '0':
ival = verinum::V0;
break;
case '1':
ival = verinum::V1;
break;
default:
ival = verinum::Vx;
break;
}
/* Take the output value and write it to all the NetNet pins
that are connected to the output pin. */
for (NetObj::Link*lnk = udp->pin(0).next_link()
; (*lnk) != udp->pin(0) ; lnk = lnk->next_link()) {
if (NetNet*sig = dynamic_cast<NetNet*>(lnk->get_obj()))
sig->set_ival(lnk->get_pin(), ival);
}
}
void propinit(Design*des)
{
des->clear_node_marks();
while (NetNode*net = des->find_node(&is_sequ_udp)) {
net->set_mark();
prop_sequdp_output(dynamic_cast<NetUDP*>(net));
}
}
/*
* $Log: propinit.cc,v $
* Revision 1.1 1998/12/20 02:05:41 steve
* Function to calculate wire initial value.
*
*/