DXF to GDSII Entity Mapping

The table below summarizing which DXF entities are mapped to GDSII entities and any limitations or cautions that one should know when preparing to make such as conversion.

DXF Entity GDSII Entity Comment
Line: not part of a boundary Path the path width will either be = 0 or the minimum line width value set in the configuration. Lines that do not form parts of a closed region can be directed to a special error layer.
Arc: not part of a boundary Path GDSII has no arc entity. Arcs are broken into vectors using the ARCRES and ARCSAG parameters in the configuration file. Arcs that do not form a closed region can be sent to the error layer.
Lines and arcs that form a closed boundary Boundary DXF2GDS attempts to form closed boundaries from lines and arcs whenever possible. Arcs are first broken into vectors using the ARCRES/ARCSAG resolution parameter, then linked. The user can configure the maximum allowable number of vertices per closed figure. While this was originally limited to 200 by the GDSII spec, the great majority of systems that read GDSII can accomodate 1024, 2048 or even 4096 vertices per boundary.
Circle Boundary Resolution determined by ARCRES/ARCSAG parameter
Polyline (constant width) Path DXF2GDS checks to see if the polyline has constant width. If so, it can translated into a path. It may also be translated into a boundary if this option is set in the configuration file.
Hatching Ignored Not supported in GDSII
Block Insert¹ SREF Structure Reference Do not attempt to use a different X-scale and Y-scale during the insertion. You may use rotation, mirroring and scaling if you know that the target GDSII system accepts such transformations.
Layer² Layer AutoCAD layer names are mapped in the configuration file to GDSII layer numbers. Layer 0 is always mapped to layer 0. The original GDSII specification supported layers 0-63 but newer EDA systems may allow much wider limits to layers such as an upper limit of 1024 or even 4096. This max layer number is configurable.
Minsert Array reference (AREF) An AutoCAD Minsert (multiple insert) is mapped to a GDSII array reference.
Point Ignored  
Solid Boundary While the Solid is supported, we don't recommend that you use this entity.
Ellipse Boundary  
Polyline of non constant width or incorporating arc sections Boundary DXF2GDS will calculate the outline of the polyline and translate to a GDSII boundary. However we don't recommend that one uses complex width changes in conjunction with bends since AutoCAD's mitering routine might not match the one used for the conversion.
Text Text Text size, mirroring, and rotation are supported. Slant and width parameters are ignored. Font data is ignored--mapped to FONT in GDSII


Notes

1. The block attributes are not passed. GDSII does not support the concept of layer associated to the insertion; all inserts in GDSII belong to layer 0.

2. Certain layer attributes such as color and linetype are not part of the stream file definition and are ignored.




GDSII to DXF

There are fewer different entities and constructions in GDSII so the mapping is simpler.

GDSII Entity DXF Entity Comment
Path Polyline of appropriate width Support 1/2W extension attribute. Does not support semicircular extension attribute. User can force paths with width into zero width closed plines in DXF
Boundary Zero width closed polyline  
Data Type Ignored  
SREF Block Insert  
AREF Block Minsert  
Text Text Font used is AutoCAD TXT
Layers Layers GDSII has layers 0-63. User can create his own layer name table for AutoCAD or can let the program use layer numbers.
Box Zero width closed polyline no comment
Plex Entity Data Plexes are structures with certain elements marked for insertion into the top layer.