is designed to be extensible in a couple
different dimensions. This leads to the possibilities of third-party
extensions that I shall call ``plug-ins''.
Plug-ins may use the VPI interface to interface with the run-time
simulation engine, or may be code generators that use the loadable
target interface. The VPI interface to Icarus Verilog is a
subset of the IEEE1364 PLI that is available with other Verilog
compilers. Modules designed using PLI are useful for extending run-time
behavior of the Verilog simulation. The loadable target interface is an
Icarus Verilog API for writing code generators. Modules designed
using this interface are useful for generating specific netlist
formats, talking with different simulation engines, or other
The rest of this page contains links to various plug-ins that people
have made available for Icarus Verilog. Some are actually
stored on the Icarus FTP site, some are stored on the author's site. In
either case, it is the author's task to maintain the particular
package. If you don't yet know about Icarus Verilog, go <here>.
This package supports distributed simulation of bus-based systems. It
includes built in support for PCI bus and other bus type models, and
support for models in Verilog and C/C++. More information is available
This VPI module provides simplified image I/O for Verilog programs. The
source is available for download at <ftp://icarus.com/pub/eda/verilog/plug-ins/image-vpi
This package supports the development of test benches for PCI devices
test. The package includes simple models for typical host devices that
share a PCI device with the device under test, including a generic host
The latter includes an interface to a C API that allows software
the device driver writers, to prototype device drivers for the device
test, and use those drivers to test the device. (This allows the
driver writers to become involved in the test of the device being
The source and binaries for some platforms are available for download
>.NOTE: This project has been replaced by Simbus described above. You probably want that instead, although pcisim is still available for legacy designs.
InFormal connects Icarus Verilog to NuSMV for formal verification (aka.
assertion based verification). The home page for Informal is
.NOTE: Links to InFormal seem to be inoperative. I do not know if it has moved, or the project is dead. Contact me if the project is alive at a new home.
This used to be called "Icarus Verilog Interactive" but has
grown beyond just Icarus Verilog. It is a graphical developer aid that
supports a variety of simulators. It may require a few minor patches to
Icarus Verilog to work, but the package includes those patches, so it
seems complete on its own. The IVI
home page is here: <http://ivi.sourceforge.net
There is a seperate project to maintain a MacOS X port of IVI, here:
Software Model Interface
The SMI is a PLI-based toolkit that uses VPI to implement a form of
interprocess communication between Verilog programs and C++ programs.
It is intended to
be more convenient the the raw VPI, which can be quite a burden when
non-trivial models are needed.
NOTE: Links to SMI seem to be dead, suggesting that it is no longer
maintained. Let me know if that is incorrect.
Python/Perl Target Module
Icarus Verilog supports loading of target modules that take on the task
of generating the desired output format. The Loadable Target API is a C
API that allows programs to write these code generators. Pinhong Chen
as written a loadable target module that offers Perl/Python support. So
if you want
your code generators, this module might help. <http://www-cad.eecs.berkeley.edu/~pinhong/scriptEDA/
VTracer is a Verilog Testbench developer aid. It
contains a Verilog-Perl co-simulation environment (based on TCP
sockets), parsers (structural Verilog, VCD/dump), and more. It's
home page is here: <http://vtracer.SourceForge.net
EDIF Target Module
This project by Vladimir Dergachev is a loadable target module, and
associated libraries, for the support of EDIF output from Icarus
Verilog. This is intended for synthesis, and he claims to support at
least Atmel AT40K chips. See
his sourceforge development page here: <http://volodya-project.sourceforge.net/tgt-edif.php
Note that this module has not been updated in a while, and the FPGA
target to Icarus Verilog does most of its job.
This is a perl script to extract hierarchy from a set of Verilog source
files. It is not really a plug-in to Icarus Verilog
that the author decided to make available. The file contains it its
a description of usage and limitations. Download it from here: <ftp://icarus.com/pub/eda/verilog/plug-ins/extract-hier/