NAME
Verilog-Perl - Overview of Verilog language packages for Perl
DESCRIPTION
The Verilog-Perl distribution provides Perl parsing and utilities for the Verilog Language. This file provides an overview of the distribution, for specific details on each component, see that component's manpage.
You may also want to try the AUTO features present in <http://www.veripool.org/verilog-mode> Verilog-Mode.
INSTALLATION
Skip this section if Verilog-Perl has already been installed.
Supported Systems
Verilog-Perl should run on any system with Perl, G++, Flex, and Bison. It is known to work on at least:
CPAN Installation
Easiest installation is using the "CPAN" command line that comes
with Perl. After configuring CPAN the first time, simply
$ cpan
cpan> install Verilog-Perl
Read the rest of this file for details on the programs provided.
Manual Installation
Download the latest version from <http://www.perl.org/CPAN/>, or
from <http://www.veripool.org/verilog-perl>.
"cd" to the directory containing this README notice.
Type "perl Makefile.PL" to configure Verilog for your system.
Type "make" to compile Verilog. Some Solaris users have had trouble
with "open" being redefined. If this happens, try editing the
Makefile to change FILEOFFSET_BITS to 32 instead of 64.
Type "make test" to check the package. If you don't have Synopsys'
VCS, the test will print a warning, which you can ignore.
Type "make install" to install the programs and any data files and
documentation.
Read the rest of this file for details on the programs provided.
SCRIPTS
The following scripts are installed by Verilog-Perl:
vhier
Vhier reads the Verilog files passed on the command line and outputs
a tree of all of the filenames, modules, and cells referenced by
that file.
vpassert
Vpassert will read the specified Verilog files and preprocess
special PLI assertions.
vppreproc
Vppreproc (Verilog-Perl Pre Processor) reads the Verilog files
passed on the command line and outputs preprocessed output.
vrename
Vrename will allow a signal to be changed across all levels of the
design hierarchy, or to create a cross reference of signal names.
PACKAGES
Verilog::Getopt
Verilog::Getopt provides standardized handling of options similar to
Verilog/VCS and cc/GCC.
Verilog::Language
Verilog::Language provides general utilities for using the Verilog
Language, such as parsing numbers or determining what keywords
exist.
Verilog::Netlist
Verilog::Netlist reads and holds interconnect information about a
whole design database.
Verilog::Netlist::Cell
A Verilog::Netlist::Cell object is created by Verilog::Netlist for
every instantiation in the current module.
Verilog::Netlist::ContAssign
A Verilog::Netlist::ContAssign object is created by Verilog::Netlist
for every continuous assignment in the current module.
Verilog::Netlist::File
Verilog::Netlist::File allows Verilog::Netlist objects to be read
and written in Verilog format.
Verilog::Netlist::Module
A Verilog::Netlist::Module object is created by Verilog::Netlist for
every module in the design.
Verilog::Netlist::Net
A Verilog::Netlist::Net object is created by
Verilog::Netlist::Module for every signal and input/output
declaration in the current module.
Verilog::Netlist::Pin
A Verilog::Netlist::Pin object is created by Verilog::Netlist::Cell
for for each pin connection on a cell.
Verilog::Netlist::Port
A Verilog::Netlist::Port object is created by
Verilog::Netlist::Module for every port connection in the module.
Verilog::Netlist::Subclas
The Verilog::Netlist::Subclass is used as a base class for all
Verilog::Netlist::* structures.
Verilog::Parser
Verilog::Parser will tokenize a Verilog file and invoke various
callback methods.
Verilog::Preproc
Verilog::Preproc reads Verilog files, and preprocesses them
according to the Verilog specification. Programs can be easily
converted from reading a IO::File into reading preprocessed output
from Verilog::Preproc.
Verilog::SigParse
Verilog::SigParser builds upon the Verilog::Parser package to
provide callbacks for when a signal is declared, a module
instantiated, or a module defined.
WHICH PARSER PACKAGE?
If you are starting a new application which needs to parse the Verilog language you have several tools available to you. Which you pick depends on how low level and complete the information you need is.
VParseBison.y
The low level VParse* source files may be of use when you need a
starting point for your own a full C++ SystemVerilog grammar parser,
using Bison and Flex. It understands the full SystemVerilog 2009
grammar (1800-2009 Appendix A).
Verilog::Preproc
Verilog::Preproc is useful when you need only text out, or a list of
defines, etc. It can preprocess a file, or be used to provide the
Verilog macro language on top of synthesis scripts. It understands
the full SystemVerilog 2009 preprocessor syntax.
Verilog::Parser
Verilog::Parser is useful when you need to tokenize or write source
filters (where you need everything including whitespace). It can
take raw files, or preprocessed input. It understands all
SystemVerilog 2005 keywords.
Abstract Syntax Tree
Verilog::Parser knows enough to make a complete Abstract Syntax Tree
(AST) of Verilog syntax, however this hasn't been implemented yet.
This would allow any arbitrary transformation of Verilog syntax
(everthing is known excluding whitespace). If you'd find this useful
please contact the author.
Verilog::SigParser
Verilog::SigParser is useful when you need a list of modules,
signals, ports, functions, etc. It requires a preprocessed file, and
can parse all SystemVerilog 2005 files, but only provides callbacks
on certain interesting things.
Verilog::Netlist
Verilog::Netlist is useful for when you need the hierarchy, and a
list of signals per module, pins per cell, etc. It builds upon the
output of Verilog::SigParser, so requires preprocessed files. It
parses all SystemVerilog 2005 files, but not all SystemVerilog
constructs are loaded into objects.
This is probably the most popular choice.
VPI Using the VPI is the best way to access the behavior of the design.
It is not part of this package as it requires a compliant simulator
and C++ code to call the VPI, and understands as much of the
language as the simulator supports. This allows writing lint checks
and full knowledge of all parts of the code, but generally requires
the most work (short of writing a parser from scratch.)
Verilator
The Verilator program also contains a very similar front end as
Verilog-Perl. It also understands how to elaborate and connect
complex pins and types. If you're looking to add some lint like
checks against netlists, this may be a better starting point.
Verilog-Mode for Emacs
Although not a parser, a common requested use of Verilog-Perl is to
automatically make shell modules and interconnect modules.
Verilog-Mode is a better solution to this problem, as it results in
completely portable code; the program (Verilog-Mode) isn't needed
for others to update the design. It's also in very common usage,
including by many IP providers.
FAQ
Why do I get "unexpected `do'" or "unexpected `bit'" errors?
Do, bit, ref, return, and other words are now SystemVerilog
keywords. You should change your code to not use them to insure it
works with newer tools. Alternatively, surround them by the Verilog
2005/SystemVerilog begin_keywords pragma to indicate Verilog 2001
code.
`begin_keywords "1364-2001"
integer bit; initial bit = 1;
`end_keywords
Alternatively use the --language (for vhier) or
Verilog::Language::language_standard call to specify "1364-2001", or
for really old code, "1364-1995".
But, again, you really should fix the Verilog code.
DISTRIBUTION
Verilog-Perl is part of the <http://www.veripool.org/> free Verilog EDA software tool suite. The latest version is available from CPAN and from <http://www.veripool.org/verilog-perl>.
Copyright 2000-2011 by Wilson Snyder. This package is free software; you can redistribute it and/or modify it under the terms of either the GNU Lesser General Public License Version 3 or the Perl Artistic License Version 2.0.
This code is provided with no warranty of any kind, and is used entirely at your own risk.
AUTHORS
Wilson Snyder <wsnyder@wsnyder.org>
SEE ALSO
vhier, vpassert, vppreproc, vrename
Verilog::EditFiles, Verilog::Getopt, Verilog::Language Verilog::Netlist, Verilog::Parser, Verilog::Preproc, Verilog::SigParser
Verilog::Netlist::Cell, Verilog::Netlist::ContAssign, Verilog::Netlist::File, Verilog::Netlist::Interface, Verilog::Netlist::ModPort, Verilog::Netlist::Module, Verilog::Netlist::Net, Verilog::Netlist::Pin, Verilog::Netlist::Port, Verilog::Netlist::Subclass,
And the <http://www.veripool.org/verilog-mode>Verilog-Mode package for Emacs.