iverilog/vvm/vvm_udp.cc

162 lines
3.5 KiB
C++

/*
* Copyright (c) 2000 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: vvm_udp.cc,v 1.2 2000/11/04 06:36:24 steve Exp $"
#endif
# include "vvm_gates.h"
vvm_udp_comb::vvm_udp_comb(unsigned w, const char*t)
: vvm_1bit_out(0), width_(w), table_(t)
{
ibits_ = new char[width_];
obit_ = 'x';
}
vvm_udp_comb::~vvm_udp_comb()
{
delete[]ibits_;
}
void vvm_udp_comb::init_I(unsigned idx, vpip_bit_t val)
{
assert(idx < width_);
if (B_IS1(val))
ibits_[idx] = '1';
else if (B_IS0(val))
ibits_[idx] = '0';
else
ibits_[idx] = 'x';
}
void vvm_udp_sequ1::take_value(unsigned key, vpip_bit_t val)
{
assert(key < width_ - 1);
ibits_[0] = obit_;
vvm_udp_comb::take_value(key+1, val);
}
void vvm_udp_comb::take_value(unsigned key, vpip_bit_t val)
{
char old_bit = ibits_[key];
init_I(key, val);
if (ibits_[key] == old_bit)
return;
for (const char*row = table_ ; row[0] ; row += width_+1) {
unsigned idx;
for (idx = 0 ; idx < width_ ; idx += 1)
{
if (row[idx] != ibits_[idx]
&& row[idx] != '?')
{
if (idx == key)
{
char new_bit = ibits_[idx];
switch (row[idx])
{
case '*':
continue;
case '_':
if (new_bit == '0')
continue;
break;
case '+':
if (new_bit == '1')
continue;
break;
case '%':
if (new_bit == 'x')
continue;
break;
case 'r':
if (old_bit=='0' && new_bit=='1')
continue;
break;
case 'R':
if (old_bit=='x' && new_bit=='1')
continue;
break;
case 'f':
if (old_bit=='1' && new_bit=='0')
continue;
break;
case 'F':
if (old_bit=='x' && new_bit=='0')
continue;
break;
case 'P':
if (old_bit=='1' && new_bit=='x')
continue;
break;
case 'N':
if (old_bit=='0' && new_bit=='x')
continue;
break;
}
// bad edge
}
break; // bad edge/level
}
}
if (idx == width_)
{
if (row[width_] == '-'
|| row[width_] == obit_)
return;
obit_ = row[width_];
switch (obit_)
{
case '0':
output(St0);
return;
case '1':
output(St1);
return;
case 'z':
output(HiZ);
return;
default:
output(StX);
return;
}
}
}
output(StX);
obit_ = 'x';
}
/*
* $Log: vvm_udp.cc,v $
* Revision 1.2 2000/11/04 06:36:24 steve
* Apply sequential UDP rework from Stephan Boettcher (PR#39)
*
* Revision 1.1 2000/03/29 04:37:11 steve
* New and improved combinational primitives.
*
*/