105 lines
3.0 KiB
C++
105 lines
3.0 KiB
C++
/*
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* Copyright (c) 1998 Stephen Williams (steve@picturel.com)
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*
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* This source code is free software; you can redistribute it
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* and/or modify it in source code form under the terms of the GNU
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* General Public License as published by the Free Software
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* Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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#if !defined(WINNT) && !defined(macintosh)
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#ident "$Id: propinit.cc,v 1.4 2000/06/25 19:59:42 steve Exp $"
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#endif
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/*
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* The propinit function runs through the devices that can impose
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* initial values in the netlist and propogates those values. The
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* process works by first scanning the active devices for outputs that
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* they generate.
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*/
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# include "netlist.h"
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/*
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* prop_sequdp_output takes the output from the located sequential UDP
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* device and propogates it to the signals connected to it.
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*/
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static bool is_sequ_udp(const NetNode*net)
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{
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const NetUDP*udp;
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if ((udp = dynamic_cast<const NetUDP*>(net)) == 0)
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return false;
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return udp->is_sequential();
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}
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static void prop_sequdp_output(NetUDP*udp)
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{
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/* Get from the UDP class the initial output value. */
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verinum::V ival;
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switch (udp->get_initial()) {
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case '0':
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ival = verinum::V0;
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break;
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case '1':
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ival = verinum::V1;
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break;
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default:
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ival = verinum::Vx;
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break;
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}
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/* Take the output value and write it to all the NetNet pins
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that are connected to the output pin. */
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Nexus*nex = udp->pin(0).nexus();
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for (Link*lnk = nex->first_nlink()
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; lnk ; lnk = lnk->next_nlink()) {
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if (NetNet*sig = dynamic_cast<NetNet*>(lnk->get_obj()))
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sig->set_ival(lnk->get_pin(), ival);
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}
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}
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void propinit(Design*des)
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{
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des->clear_node_marks();
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while (NetNode*net = des->find_node(&is_sequ_udp)) {
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net->set_mark();
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prop_sequdp_output(dynamic_cast<NetUDP*>(net));
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}
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}
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/*
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* $Log: propinit.cc,v $
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* Revision 1.4 2000/06/25 19:59:42 steve
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* Redesign Links to include the Nexus class that
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* carries properties of the connected set of links.
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*
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* Revision 1.3 2000/05/07 04:37:56 steve
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* Carry strength values from Verilog source to the
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* pform and netlist for gates.
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*
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* Change vvm constants to use the driver_t to drive
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* a constant value. This works better if there are
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* multiple drivers on a signal.
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*
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* Revision 1.2 2000/02/23 02:56:55 steve
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* Macintosh compilers do not support ident.
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*
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* Revision 1.1 1998/12/20 02:05:41 steve
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* Function to calculate wire initial value.
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*
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*/
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