net_udp.cc

   1 /*
   2  * Copyright (c) 2000 Stephen Williams (steve@icarus.com)
   3  * Copyright (c) 2001 Stephan Boettcher <stephan@nevis.columbia.edu>
   4  *
   5  *    This source code is free software; you can redistribute it
   6  *    and/or modify it in source code form under the terms of the GNU
   7  *    General Public License as published by the Free Software
   8  *    Foundation; either version 2 of the License, or (at your option)
   9  *    any later version.
  10  *
  11  *    This program is distributed in the hope that it will be useful,
  12  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *    GNU General Public License for more details.
  15  *
  16  *    You should have received a copy of the GNU General Public License
  17  *    along with this program; if not, write to the Free Software
  18  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  19  */
  20 #ifdef HAVE_CVS_IDENT
  21 #ident "$Id: net_udp.cc,v 1.10 2004/10/04 01:10:54 steve Exp $"
  22 #endif
  23
  24 # include  "config.h"
  25 # include  "compiler.h"
  26
  27 # include  "netlist.h"
  28
  29 NetUDP::NetUDP(NetScope*s, perm_string n, unsigned pins, PUdp *u)
  30   : NetNode(s, n, pins), udp(u)
  31 {
  32       pin(0).set_dir(Link::OUTPUT);
  33       pin(0).set_name(perm_string::literal("O"), 0);
  34       for (unsigned idx = 1 ;  idx < pins ;  idx += 1) {
  35             pin(idx).set_dir(Link::INPUT);
  36             pin(idx).set_name(perm_string::literal("I"), idx-1);
  37       }
  38 }
  39
  40 bool NetUDP::first(string&inp, char&out) const
  41 {
  42   table_idx = (unsigned) -1;
  43   return next(inp, out);
  44 }
  45
  46 bool NetUDP::next(string&inp, char&out) const
  47 {
  48   table_idx++;
  49
  50   if (table_idx >= udp->tinput.count())
  51     return false;
  52
  53   if (is_sequential())
  54     {
  55       inp = string("") + udp->tcurrent[table_idx] + udp->tinput[table_idx];
  56       assert(inp.length() == pin_count());
  57     }
  58   else
  59     {
  60       inp = udp->tinput[table_idx];
  61       assert(inp.length() == (pin_count()-1));
  62     }
  63
  64   out = udp->toutput[table_idx];
  65   assert( (out == '0')
  66        || (out == '1')
  67        || (out == 'x')
  68        || (is_sequential() && (out == '-')));
  69
  70   return true;
  71 }
  72
  73 char NetUDP::get_initial() const
  74 {
  75   assert (is_sequential());
  76
  77   switch (udp->initial)
  78     {
  79     case verinum::V0:
  80       return '0';
  81     case verinum::V1:
  82       return '1';
  83     case verinum::Vx:
  84     case verinum::Vz:
  85       return 'x';
  86     }
  87
  88   assert(0);
  89   return 'x';
  90 }
  91
  92
  93 /*
  94  * $Log: net_udp.cc,v $
  95  * Revision 1.10  2004/10/04 01:10:54  steve
  96  *  Clean up spurious trailing white space.
  97  *
  98  * Revision 1.9  2004/02/18 17:11:56  steve
  99  *  Use perm_strings for named langiage items.
 100  *
 101  * Revision 1.8  2003/03/06 00:28:42  steve
 102  *  All NetObj objects have lex_string base names.
 103  *
 104  * Revision 1.7  2002/08/12 01:34:59  steve
 105  *  conditional ident string using autoconfig.
 106  *
 107  * Revision 1.6  2001/07/25 03:10:49  steve
 108  *  Create a config.h.in file to hold all the config
 109  *  junk, and support gcc 3.0. (Stephan Boettcher)
 110  *
 111  * Revision 1.5  2001/04/24 02:23:58  steve
 112  *  Support for UDP devices in VVP (Stephen Boettcher)
 113  *
 114  * Revision 1.4  2001/04/22 23:09:46  steve
 115  *  More UDP consolidation from Stephan Boettcher.
 116  *
 117  * Revision 1.3  2000/12/15 01:24:17  steve
 118  *  Accept x in outputs of primitive. (PR#84)
 119  *
 120  * Revision 1.2  2000/11/04 06:36:24  steve
 121  *  Apply sequential UDP rework from Stephan Boettcher  (PR#39)
 122  *
 123  * Revision 1.1  2000/03/29 04:37:11  steve
 124  *  New and improved combinational primitives.
 125  *
 126  */
 127