GDSII stream format, common acronym GDSII, is a database file format which is the de facto industry standard for data exchange of integrated circuit or IC layout artwork. It is a binary file format representing planar geometric shapes, text labels, and other information about the layout in hierarchical form. The data can be used to reconstruct all or part of the artwork to be used in sharing layouts, transferring artwork between different tools, or creating photomasks.

Developed byCalma
A rendering of a small GDSII standard cell with three metal layers (dielectric has been removed). The sand-colored structures are metal interconnect, with the vertical pillars being contacts, typically plugs of tungsten. The reddish structures are polysilicon gates, and the solid at the bottom is the crystalline silicon bulk.

History of the GDSII formatEdit

GDS = Graphic Design System (see [GDS78])

Initially, GDSII was designed as a stream format used to control integrated circuit photomask plotting. Despite its limited set of features and low data density, it became the industry conventional stream format for transfer of IC layout data between design tools of different vendors, all of which operated with proprietary data formats.

It was originally developed by Calma for its layout design system, "Graphic Design System" ("GDS") and "GDSII".

GDSII files are usually the final output product of the IC design cycle and are handed over to IC foundries for IC fabrication. GDSII files were originally written on magnetic tapes; this step was fittingly called tape out, although that term goes back even farther.

Objects contained in a GDSII file are grouped by assigning numeric attributes to them including a "layer number", "datatype" or "texttype". While these attributes were designed to correspond to the "layers of material" used in manufacturing an integrated circuit, their meaning rapidly became more abstract to reflect the way that the physical layout is designed.

As of October 2004, many EDA software vendors have begun to support a new stream format, OASIS, which may replace GDSII.[1]

GDSII utilitiesEdit

As the GDSII stream format is a de facto standard, it is supported by nearly all EDA software. Besides the commercial vendors there are plenty of free GDSII utilities. These free tools include editors,[2][3][4] viewers,[5] utilities to convert the 2D layout data into common 3D formats,[6][7] utilities to convert the binary format to a human readable ASCII format[8] and program libraries.[9][10][11]

See alsoEdit


  1. ^ Going from GDSII to OASIS, Philippe Morey-Chaisemartin (Xyalis) // EETimes 8/4/2008
  2. ^ LayoutEditor, a free GDSII editor
  3. ^ "KLayout" is a free GDSII, LEF/DEF, OASIS, Gerber, DXF, CIF editor with DRC
  4. ^ Glade, a free GDSII, LEF/DEF editor
  5. ^ "nanoViewer" is a free GDSII viewer, Archived 2012-01-19 at the Wayback Machine
  6. ^ gds2pov easily convert GDSII data into a nicely rendered 3D view.
  7. ^ With GdsViewer tool, any portion of GDSII artwork can be exported to 3D VTK file. The latter can be viewed and manipulated with VTK compatible viewers, e.g. ParaView
  8. ^ GDS Utilities can convert binary GDSII files to ASCII representation,
  9. ^ Ruby GDSII Library for reading, manipulating, and writing GDSII data in the Ruby programming language
  10. ^ Python GDSII Library for creating and manipulating GDSII files with Python
  11. ^ Octave and MATLAB toolbox for reading and writing GDSII layout files


* Clein, Dan. (2000). CMOS IC Layout. Newnes. ISBN 0-7506-7194-7
* [GDS78] Calma. (1978). GDS II Graphic Design System User's Operating Manual, First Edition 1978. Online at Retrieved Apr 21, 2020.

External linksEdit