Ruby-VPI
Ruby-VPI is a platform for unit testing, rapid prototyping, and systems integration of Verilog modules through the Ruby programming language. It lets you:
- Access the entire IEEE 1364-2005 Verilog VPI interface from Ruby.
- Create complex Verilog test benches easily and wholly in Ruby.
- Apply agile software development practices to develop hardware.
- Perform specification-driven functional verification (PDF version).
Ruby-VPI is open source software released under this license.
1 Resources
Records
- What’s new – a history of all release notes.
- Plans – pending tasks for future releases.
- Talks – materials from presentations and seminars.
- Papers – research publications.
- Motivation – why does Ruby-VPI exist?
Documentation
- User manual
– complete documentation for users. Start here!
- Tutorial – learn how to use Ruby-VPI quickly.
- Reference – API documentation for Ruby libraries and C extension.
Facilities
- Downloads – obtain release packages
- Source code – browse online or obtain with Darcs.
- Forums – discuss things and ask questions.
- Bugs – report defects in the software.
- Patches – submit patches to source code.
- Requests – request new features or get support.
- Project portal – hosted generously by RubyForge.
2 Features
Portable
- Supports the entire IEEE 1364-2005 Verilog VPI standard.
- Works with all major Verilog simulators available today.
- Compiled just once during installation and used forever!
Agile
- Enables agile practices such as
- test-driven development
- behavior-driven development
- rapid prototyping for design exploration
- Eliminates unneccesary work:
- Specifications are readable, portable, and executable.
- The automated test generator helps you accomodate design changes with minimal effort.
- There is absolutely no compiling!
Powerful
- Inherits the power and elegance of Ruby:
- Unlimited length integers
- Regular expressions
- Multi-threading
- System calls and I/O
- ad infinitum
- Uses ruby-debug for interactive debugging.
- Uses rcov for test coverage analysis and report generation.
3 Requirements
The following software is necessary in order to use Ruby-VPI.
Verilog simulator
Ruby-VPI is known to work with the following simulators. However, you should be able to use it with any Verilog simulator that supports VPI.- Synopsys VCS – any version that supports the -load option is acceptable.
- Mentor Modelsim – any version that supports the -pli option is acceptable.
- Cadence NC-Sim / NC-Verilog – any version that supports the +loadvpi option is acceptable.
- GPL Cver – version 2.11a or newer is acceptable.
- Icarus Verilog – version 0.8 is mostly acceptable—you will not be able to access child handles through method calls. The reason for this limitation is explained in the user manual.
Compilers
- make – any flavor should be acceptable.
- C compiler – the GNU Compiler Collection is preferred, but any C compiler should be acceptable.
- Ruby – version 1.8 or newer, including header and linkable object files for building extensions, is necessary. You can install Ruby by following these instructions.
Libraries
- POSIX threads – header and linkable object files, and operating system support for this library are necessary.
- RubyGems – any recent version should be acceptable. You can install RubyGems by following these instructions.
4 Applications
Examples of tasks that can be performed with Ruby-VPI are:- From the second edition of The Verilog PLI Handbook:
- C language bus-functional models
- Reading test vector files
- Delay calculation
- Custom output displays
- Co-simulation
- Design debug utilities
- Simulation analysis
- Adapted from Pin Hong’s observations:
- Writing hardware models in Ruby
- Dumping or processing netlist data from Verilog database
- Dumping or processing simulation data
- Feeding dynamic simulation stimuli
- Back-annotating delay information
- Interactive logic simulation
- Building a distributed simulation
5 Appetizers
Here is a tiny sampling of code to whet your appetite. See the tutorial for more samples.
- Assign the value 22048 to a register:
your_register.intVal = 2 ** 2048
- Check if all nets in a module are at high impedance:
your_module.all_net? { |net| net.z? }
- See a register’s path, width, and location (file & line number):
puts your_register
- Access the first five elements in a memory:
your_memory.memoryWord_a[0..4]
- Clear a memory by filling it with zeroes:
your_memory.each_memoryWord {|w| w.intVal = 0}
6 License
Copyright 2006 Suraj N. Kurapati <snk@gna.org>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
1. All modified and unmodified copies and substantial portions of the Software (the "Derivatives") and their corresponding machine-readable source code (the "Code") must include the above copyright notice and this permission notice.
2. Upon distribution, the Derivatives must be accompanied either by the Code or, if the Code is obtainable for no more than the cost of distribution plus a nominal fee, by information on how to obtain the Code.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.