Philip Moorby

Philip Moorby

2016 Fellow

For his invention and promotion of the Verilog hardware description language.


Born and raised in Birmingham, United Kingdom, Philip Moorby studied mathematics as an undergraduate at Southampton University followed by a master's degree in computer science from Manchester University in 1974. At Manchester, Moorby worked on the one-of-a-kind and influential MU5 computer system, designing a circuit module tester for the MU5 interfaced to a DEC PDP-8 minicomputer.

”I chose a project that spanned both hardware and software because I couldn't make a decision which way to go. 'Okay,' I thought, 'well I like hard problems, big problems,' so I did both,” Moorby said in his 2013 Computer History Museum oral history.

After graduating from Manchester, Moorby became interested in a new field: computer-aided design (CAD). In 1976 he began doctoral studies at Brunel University near London, while also joining a team developing HILO, an early hardware description language (HDL) project funded by the UK Ministry of Defence. Moorby worked on the second iteration of HILO, developing simulators and working in the BCPL programming language on a Honeywell Multics system. In 1979 Moorby began full-time work on HILO while continuing his PhD program. Soon after the HILO project was taken up by Cirrus Computer Ltd.

In 1983 Moorby left the UK to join startup Gateway Design Automation in the US, along with Prabhu Goel and Chi-Lai Huang. Gateway had test generation and hardware fault simulation products under development, and ultimately intended to offer logic synthesis. Moorby knew this would require a new language and a new simulator - and, in the span of one month, he invented the Verilog hardware description language. Over the following year, Moorby wrote the first Verilog simulator, which came to market in early 1985.

By 1987 Moorby had written an even faster logic simulator called Verilog-XL, which boasted gate-level simulation speeds approaching that of hardware accelerators. The Verilog-XL simulator Moorby designed found adoption quickly with companies such as AMD, Apollo, Sun, Hughes Aircraft, and General Electric. The goal for Verilog-XL was to be the “golden simulator,” used for final signoff by application-specific integrated circuit (ASIC) designers and vendors. Early users included major vendors such as Motorola and Fujitsu.

Verilog-XL was a landmark product, rapidly gaining market share in an industry where there were several competing digital simulators. The success of Verilog-XL led to Gateway becoming one of the leading simulation companies in the world. Cadence Design Systems purchased Gateway in 1989. Moorby was named Cadence's first Corporate Fellow.

After departing Cadence in 1992, Moorby developed an interest in video manipulation, first going to Avid, the leader in non-linear editing, and then on to a startup attempting to create software to create 3D models for film and video. Moorby returned to the world of electronic design automation (EDA) with Co-Design, a company founded by Simon Davidmann and Peter Flake, where he worked on a new simulator and a new language called Superlog, which evolved from Verilog. When Co-Design was bought by Synopsys in 2002, Moorby stayed on for six years, working on simulators and shepherding Superlog into SystemVerilog.

Moorby's invention of Verilog has enabled the creation of the multibillion transistor devices we use every day, devices that push the limits of engineering, chemistry, and physics. Only with the use of powerful electronic design automation software - of which Verilog is the gold standard - has it been possible for IC designers to manage the mind-boggling complexity of integrated circuit technology.