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Layer and Data Type Discrimination

While AutoCAD uses the concept of layer "names" to segregate data, GDSII entities are assigned layer numbers. ASM 3500 includes the ability to map AutoCAD layer names into GDSII layer numbers. (Exception - AutoCAD's layer 0 is always mapped to GDSII layer 0.)

However GDSII geometries can be marked with a second attribute which is equivalent to layers called "datatype." Datatype can be assigned to any entity to meet a designer's needs. For example, the designer might want to mark certain entities on a layer as dummy fill elements by assigning them a different datatype.

Artwork has added data type discrimination to our command line engine (as of version 6.73 August 30, 2014) through this feature is not accessible via the GUI.

The range of layer and datatype integers are: 0-8191. However one should first know the limitations of the target system before assigning high values of layer and datatype as the original GDSII spec allowed only a range of 0-63.

How it Works

Layer Mapping is controlled in the configuration file (by default called gds.cfg) The Layer arguments now suport datatype. Let's look at three examples:

mapping from DXF to GDSII layer datatype

Case 1 - No datatype discrimination

RDL 30
UBM 60

Note: when no datatype is specified, the default datatype = 0 going from DXF to GDSII.

Case 2 - Unique Layer:Datatype for each DXF layer

RDL 30:20
UBM 60:10

Case 3 - Same Layer, Unique Datatype

RDL 10:30
UBM 10:60