Verilog is a hardware description language (HDL) that was first introduced in the 1980s by Gateway Design Automation, a company founded by Phil Moorby and Prabhu Goel. The initial version of Verilog, known as Verilog-X, was designed to simulate digital circuits and was based on the C language.
In 1989, Moorby and Goel released Verilog-87, which was the first version of Verilog to support the description of digital circuits using high-level behavioral modeling. This allowed designers to describe the behavior of a circuit in terms of its inputs and outputs, rather than its internal structure.
Verilog-95 was released in 1995 and introduced several new features, including the ability to describe circuits using modules, which are building blocks of digital circuits. This allowed designers to create modular designs that could be easily reused and tested.
In 1999, the Verilog standard was updated again with the release of Verilog-2001, which introduced several new features, including parameterized modules, which allowed designers to create generic modules that could be customized for specific applications.
In 2005, the IEEE standard 1364-2005 was released, which included several new features and improvements to the Verilog language. This became known as SystemVerilog, which is an extension of Verilog that includes features for designing and verifying complex digital systems.
Today, Verilog and SystemVerilog are widely used in digital circuit design and verification, and are supported by most electronic design automation (EDA) software tools. The language has continued to evolve over the years and remains an important tool for designing and verifying digital circuits.