Liberty Library Modeling 

The EDA library modeling standard 

Liberty is the gate-level modeling technology that powers Synopsys’ leading Galaxy implementation and sign-off tools. An open industry standard for almost a decade, the Liberty library format is used by virtually all EDA implementation, analysis and library characterization tools as the library model exchange for timing, noise, power and test behavior. Through industry guidance by the Liberty Technology Advisory Board (TAB), the Liberty modeling standard continues to evolve to meet today’s design challenges through accurate modeling of advanced nanometer effects. The latest example is Liberty Composite Current Source (CCS) modeling technology which is the first in the industry to deliver a unified current based modeling solution for timing, noise and power. Liberty is available for download to the entire semiconductor design community under standard open-source terms.

Synopsys support for Liberty
From the earliest days of Synopsys, its library modeling format – which was the genesis of today’s Liberty standard - has been at the heart of its electronic design tools. Liberty is the key modeling format that spans Synopsys’ solutions, platforms, tools, and IP.

Background
Over the past 20 years, Synopsys has evolved the Liberty standard to address complex library modeling requirements. Liberty was originally invented in 1987 to support the needs of Design Compiler, then expanded to handle additional requirement for power optimization in Power Compiler and sign-off static timing analysis for PrimeTime. In 2000, the Liberty standard became among the first EDA standards to be provided as Open Source to foster innovation and interoperability for a wide variety of EDA applications. In May 2006, Synopsys and Silicon Integration Initiative (Si2), a semiconductor industry consortium, launched an industry-wide Liberty Technical Advisory Board (TAB) to facilitate the evolution of the Liberty library modeling standard.

The Liberty TAB was expanded in May 2008 as it moved to the auspices of the IEEE Industry Standards and Technology Organization (IEEE-ISTO) to include more participants from the foundry and electronic design automation (EDA) industries. The Liberty TAB and its industry-leading member companies will continue to guide the evolution of the Liberty standard for library modeling, with a focus on improved productivity and reducing costs in creating and producing integrated silicon systems.

Today, the open source Liberty modeling format is the semiconductor industry’s most widely adopted library standard. It is supported by:

  • Over 100 semiconductor vendors
  • Over 750 submicron libraries
  • Over 60 EDA vendors
  • Over 75 production EDA tools