| DXF Entity | GDSII Entity | Comment |
|---|---|---|
Line: not part of a boundary |
Path |
The original GDSII supports a maximum of 200 vertices per trace definition. However the program can be configured to allow a maximum of 8191 vertices per trace or boundary which is the upper limit those records support. |
Arc: not part of a boundary |
Path |
GDSII has no arc entity. Arcs are broken into vectors using the ARCRES or the CHORD ERROR parameter in GDS.CFG file. |
Lines and arcs that form a closed boundary |
Boundary |
ACAD2GDS attempts to form closed boundaries from lines and arcs whenever possible. Arcs are first broken into vectors using the ARCRES/CHORD ERROR parameters, then linked. ASM 3500 allows the user to set the max number of vertices to 8191. |
Splines |
segments for Linking |
The DXF spline entity is broken into segments which can either then be linked into a boundary or a zero width path. |
Circle |
Boundary |
Resolution determined by ARCRES parameter and the ARCSAG parameter. |
Polyline (constant width) |
Path |
DXF2GDS checks to see if the polyline has constant width. If so, it translated into a path. If not, it is translated into a boundary. Mitering of Bends is controlled by the parameter: Path Mitering. |
Hatching |
Ignored |
Not supported in GDSII |
Block Insert¹ |
Structure Reference |
Inserts may be nested 32 deep |
Layer² |
Layer |
The original GDSII spec supports layers 0-63. The user can control layer name to number mapping or let the program do this automatically. Many programs support more than layers 0-63. ASM 3500 allows you to define a layer number up to 8191. |
Minsert |
Array reference (AREF) |
MINSERT in DXF (Multiple Insertion) is converted into an AREF in GDSII. |
Point |
Ignored |
there is no GDSII equivalent. |
Solid |
Boundary |
watch out for Bow-Tie solids which are illegal boundaries. |
Ellipse |
Boundary. The ARCRES/CHORD ERROR parameters determine how many boundary segments are generated. |
|
Polyline of non constant width or incorporating arc sections |
Boundary |
ACAD2GDS will calculate the outline of the polyline and translate to a GDSII boundary. |
Text |
Text |
Text size, mirroring, width factor, and rotation are supported. Font data is ignored if the text in DXF is converted into text in GDSII; it is used if the text in DXF is converted into boundaries or paths in GDSII. |
Notes:
1. Block attributes are not passed. GDSII does not support the concept of layer associated to the insertion.
2. Certain layer attributes such as color and linetype are not part of the stream file definition and are ignored.
| GDSII Entity | DXF Entity | Comment |
|---|---|---|
Path |
Polyline of appropriate width or zero width closed polyline. |
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 |
If CIRCLE=ON then "round" boundaries will be converted into AutoCAD circles. Ideal for GDSII files that originate from package or PCB layouts. |
Data Type |
Ignored |
no equivalent in DXF |
SREF |
Block Insert |
|
AREF |
Block Minsert |
|
Text |
Text |
User can specify DXF STYLE and FONT |
Layers |
Layers |
Original GDSII spec supported layers 0-63; extended GDSII can go up to layer 8191 depending on the application that reads the GDSII. User can create his own layer name table for AutoCAD or can let the program use layer numbers. |
Box |
Zero width closed polyline |
The GDSII BOX is a rarely used entity. |
Plex |
Entity Data |
Plexes are structures with certain elements marked for insertion into the top layer. |