Library Exchange Format (LEF) is a specification for representing the

physical layout Integrated circuit layout, also known IC layout, IC mask layout, or mask design, is the representation of an integrated circuit in terms of planar geometric shapes which correspond to the patterns of metal, oxide, or semiconductor layers that make ...

of an

integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...

in an

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...

format. It includes design rules and abstract information about the standard cells. LEF only has the basic information required at that level to serve the purpose of the concerned CAD tool. It helps in saving valuable resources by providing only an abstract view and thus consuming less memory overhead. LEF is used in conjunction with

Design Exchange Format {{about, the specification for representing a circuit, the CAD data file format, AutoCAD DXF Design Exchange Format (DEF) is an open specification for representing physical layout of an integrated circuit in an ASCII ASCII ( ), abbreviat ...

(DEF) to represent the complete

of an

while it is being designed. LEF originated by Tangent for their Place and Route (P&R) tools, which were bought by

Cadence Design Systems Cadence Design Systems, Inc. (stylized as cādence), headquartered in San Jose, California, is an American multinational corporation, multinational computational software company, founded in 1988 by the merger of SDA Systems and ECAD, Inc. The co ...

.Smith, Michael J. S., Application-Specific Integrated Circuits, Addison-Wesley, 1997, page 897.

References

{{Reflist EDA file formats