Free VHDL Simulators for Beginners: GHDL, ModelSim, Vivado, and VUnit

If you're new to VHDL (VHSIC Hardware Description Language) and looking for a way to compile and simulate your VHDL code, you're in the right place. There are several free VHDL simulators available that can help you get started without any cost. This article will introduce you to some of the most popular options, including their features, installation processes, and basic usage.

1. GHDL

Description

GHDL is an open-source VHDL simulator that supports VHDL-2008. It is highly versatile and can be used on various platforms including Windows, Linux, and macOS. GHDL is particularly known for its compatibility and performance, making it a preferred choice for developers and hobbyists alike.

Installation

Installing GHDL is straightforward, whether you're using Ubuntu, macOS, or another distribution. For Ubuntu, you can use the package manager apt by running:

sudo apt install ghdl

For macOS, you can use Homebrew to install GHDL by executing the following command in your terminal:

brew install ghdl

Getting Started with GHDL

To get started with GHDL, follow these steps:

Install GHDL using the appropriate method for your operating system.

Write your VHDL code in a file, for example, example.vhdl.

Compile your VHDL code using GHDL by running:

ghdl -a example.vhdl

Here, -a stands for "assembly," which assembles the source code into an intermediate representation.

Elaborate your design:

ghdl -e example_entity

Here, example_entity should be replaced with the actual name of your top-level entity.

Run your simulation:

ghdl -r example_entity

Replace example_entity with the actual name of your top-level entity.

2. ModelSim Student Edition

Description

ModelSim offers a free Student Edition that is limited in terms of simulation capacity but still powerful for educational purposes. This version is ideal for students and beginners who want to explore VHDL without any cost.

Installation

To use ModelSim, you need to register for a free account on the Mentor Graphics website. After registration, you can download the ModelSim Student Edition from their official website.

3. Vivado WebPACK Edition

Description

Xilinx Vivado offers a WebPACK edition that includes a free VHDL simulator. While primarily designed for Xilinx FPGA development, it can be used for VHDL simulation as well. This version is particularly useful if you're working with Xilinx FPGAs.

Installation

To use Vivado WebPACK, you need to create an account on the Xilinx website. After signing up, you can download the WebPACK edition from there.

4. Sigasi Studio Free Trial

Description

Sigasi Studio offers a free trial version with advanced features for VHDL development and simulation. Although it is not entirely free, it allows you to explore its capabilities and decide if you want to upgrade to a full license.

Installation

Download Sigasi Studio from their website and follow the installation instructions provided there.

5. VUnit

Description

VUnit is an open-source VHDL unit testing framework that integrates with other simulators like GHDL. It helps in writing and running tests for your VHDL code, making it easier to verify and debug your designs.

Installation

You can find VUnit on GitHub and follow the installation instructions provided there.

Conclusion

These free VHDL simulators and tools should help you get started with VHDL simulation without any cost. Whether you're a beginner, a student, or a hobbyist, there's a simulator that can cater to your needs. Experiment with each of these tools to find which one works best for you and your projects.