iverilog/vvp/udp.h

125 lines
3.8 KiB
C++

#ifndef __udp_H
#define __udp_H
/*
* Copyright (c) 2005 Stephen Williams (steve@icarus.com)
*
* (This is a rewrite of code that was ...
* Copyright (c) 2001 Stephan Boettcher <stephan@nevis.columbia.edu>)
*
* 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
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: udp.h,v 1.16 2005/04/03 05:45:51 steve Exp $"
#endif
# include <vvp_net.h>
# include <delay.h>
/*
* The vvp_udp_s instance represents a *definition* of a
* primitive. netlist instances refer to these definitions.
*
* The ports argument of the constructor is the number of input ports
* to the device. The single output port is not counted. The port
* count must be greater then 0.
*
* A level sensitive UDP has a table that includes all the rows that
* generate a 0 output and another table that includes all the rows
* that generate a 1 output. A set of inputs is tested against the
* entries in both sets, and if there are no matches, the output is
* set to x.
*
* The levels0 and levels1 tables are each an array of levels
* tables. Each levels table is a mask of positions that are supposed
* to be 0, 1 and x. The LSB of each mask represents first port, and
* so on. If the bit is set in mask0, a bit4_0 is expected at that
* position, and similarly for mask1 and maskx. Only exactly 1 bit
* will be set in the three masks for each bit position.
*
* This table structure implies that the number of inputs to the level
* sensitive device is limited to the number of bits in an unsigned long.
*/
struct udp_levels_table {
unsigned long mask0;
unsigned long mask1;
unsigned long maskx;
};
class vvp_udp_s {
public:
vvp_udp_s(char*label, char*name, unsigned ports, bool sequ);
~vvp_udp_s();
void compile_table(char**tab);
// Return the number of input ports for the defined UDP.
unsigned port_count() const;
// Test the cur table with the compiled rows, and return the
// bit value that matches.
vvp_bit4_t test_levels(const udp_levels_table&cur);
private:
char*name_;
unsigned ports_;
// Level sensitive rows of the device.
struct udp_levels_table*levels0_;
struct udp_levels_table*levels1_;
unsigned nlevels0_, nlevels1_;
};
/*
* Ths looks up a UDP definition from its LABEL.
*/
struct vvp_udp_s *udp_find(const char *label);
/*
* The udp_fun_core is the core of the udp instance in the
* netlist. This core is a vvp_wide_fun_core that takes care of
* dispatching the output. This class also receives the inputs from
* the vvp_wide_fun_t objects and processes them to generate the
* output to be sent.
*/
class vvp_udp_fun_core : public vvp_wide_fun_core {
public:
vvp_udp_fun_core(vvp_net_t*net, vvp_udp_s*def, vvp_delay_t*del);
~vvp_udp_fun_core();
void recv_vec4_from_inputs(unsigned);
private:
vvp_udp_s*def_;
vvp_delay_t*delay_;
vvp_bit4_t cur_out_;
udp_levels_table current_;
};
/*
* $Log: udp.h,v $
* Revision 1.16 2005/04/03 05:45:51 steve
* Rework the vvp_delay_t class.
*
* Revision 1.15 2005/04/01 06:02:45 steve
* Reimplement combinational UDPs.
*
*/
#endif