.TH iverilog 1 "April, 2000" Version 19990913
.SH NAME
iverilog - Icarus Verilog compiler

.SH SYNOPSIS
.B iverilog
[-Dmacro[=defn]] [-E] [-fflag=value] [-Iincludepath] [-mmodule] [-ooutputfilename] [-stopmodule] [-ttype] [-v] sourcefile[s]

.SH DESCRIPTION
.PP
\fIiverilog\fP is a compiler that translates Verilog source code into
executable programs for simulation, or other netlist formats for
further processing. The currenty supported targets are \fIvvm\fP (for
executable simulation) and \fIxnf\fP for synthesis. Other target
types are added as code generators are implemented.

.SH OPTIONS
.l
\fIiverilog\fP accepts the following options:
.TP 8
.B -D\fImacro\fP
Defines macro \fImacro\fP with the string `1' as its definition. (NOT IMPLEMENTED)
.TP 8
.B -D\fImacro=defn\fP
Defines macro \fImacro\fP as \fIdefn\fP. (NOT IMPLEMENTED)
.TP 8
.B -E
Preprocess the Verilog source, but do not compile it. The output file
is the Verilog input, but with file inclusions and macro references
expanded and removed. This is useful, for example, to preprocess
verilog source for use by other compilers.
.TP 8
.B -f\fIflag=value\fP
Assign a value to a target specific flag. The \fB-f\fP switch may be
used as often as necessary to specify all the desired flags. The flags
that are used depend on the target that is selected, and are described
in target specific documentation. Flags that are not used are ignored.
.TP 8
.B -I\fIincludepath\fP 
Append path \fIincludepath\fP to list of paths searched for Verilog
include files. (NOT IMPLEMENTED)
.TP 8
.B -m\fImodule\fP
Add this module to the list of VPI modules to be loaded by the
simulation. (NOT IMPLEMENTED)
.TP 8
.B -o \fIfilename\fP
Place output in the file \fIfilename\fP. If no output file name is
specified, \fIiverilog\fP uses the default name \fBa.out\fP.
.TP 8
.B -s \fItopmodule\fP
Specify the top level module to elaborate. Icarus Verilog will by default
choose the only module that has no ports. However, this simplistic
heuristic is often not sufficient, and sometimes not what is wanted
anyhow.
.TP 8
.B -v
Turn on verbose messages. This will print the command lines that are
executed to perform the actual compilation, along with version
information from the various components.

.SH TARGETS

The Icarus Verilog compiler supports a variety of targets, for
different purposes, and the \fB-t\fP switch is used to select the
desired target.

.TP 8
.B null
The null target causes no code to be generated. It is useful for
checking the syntax of the Verilog source.
.TP 8
.B vvm
This is the default. The target is an executable program that uses the
vvm simulation runtime. The compiler actually generates C++ code, then
compiles and links that code to make the output executable.
.TP 8
.B xnf
This is the Xilinx Netlist Format used by many tools for placing
devices in FPGAs or other programmable devices. The Icarus Verilog XNF
code generator can generate complete designs or XNF macros that can be
imported into larger designs by other tools.

.SH EXAMPLES 
These examples assume that you have a Verilog source file called hello.v in
the current directory

To compile hello.v to an executable file called a.out:

	verilog hello.v

To compile hello.v to an executable file called hello:

	verilog -o hello hello.v

To compile hello.v to a file in XNF-format called hello.xnf

	verilog -txnf -ohello.xnf hello.v


.SH "AUTHOR"
.nf
Steve Williams (steve@icarus.com)

.SH SEE ALSO
.BR "<http://www.icarus.com/eda/verilog/>"

.SH COPYRIGHT
.nf
Copyright \(co  2000 Stephen Williams

This document can be freely redistributed according to the terms of the 
GNU General Public License version 2.0