LEF/DEF Language Reference

LEF & DEF are common use files in IC design. For most EDA tools, LEF & DEF files are standard interface files. You can write your design to def & lef, and import it in other tools.

LEF & DEF are common use files in IC design. For most EDA tools, LEF & DEF files are standard interface files. You can write your design to def & lef, and import it in other tools.

What is LEF?

A Library Exchange Format (LEF) file contains library information for a class of designs.  Library data includes layer, via, placement site type, and macro cell definitions. The LEF file is an ASCII representation using the syntax conventions described in Cadence LEF/DEF Reference Document. 

What is DEF?

A Design Exchange Format (DEF) file contains the design-specific information of a circuit and is a representation of the design at any point during the layout process.  The DEF file is an ASCII representation using the syntax conventions in Cadence LEF/DEF Reference Document.  DEF conveys logical design data to, and physical design data from, place-and-route tools.  Logical design data can include internal connectivity (represented by a netlist), grouping information, and physical constraints. Physical data includes placement locations and orientations, routing geometry data, and logical design changes for back-annotation. Place-and-route tools also can read physical design data, for example, to perform ECO changes.

LEF/DEF Language Reference:

The attachment is LEF/DEF Language Reference file in PDF format, it is the manual for LEF/DEF format. Click Here to download it: lefdefref.zip

Leave a Reply

Your email address will not be published. Required fields are marked *