GDSSCALE is a utility program that can be used to scale or transform GDSII data. It is useful when one has to match units of different GDSII files to be combined or when one needs to center or rotate or mirror GDSII data.

The output is the same GDSII file with all cell names and hierarchy and layers/datatypes preserved.

Units Transformation

Occasionally an engineer needs to convert a GDSII file from one unit to another. For example, an incoming file may be in MM and it is needed in UM to work with some other tools.

In that case the user need only run GDSSCALE with a -outunit:UM on the command line and the input file will be converted to an output file with new units (and resolution) Any scaling of data needed to support the new unit/grid is automatically performed.

Physical Transformation

There are other times when an incoming GDSII file needs to be physically transformed. Examples of this are offset (to center the data) or rotation or mirroring or even scaling.

All of these transformations are available using the -xform: directive on the command line.

Command Line Syntax

The gdsscale uses the following command line syntax:

gdsscale64.exe   input_file   output_file   -xform:parameters  -output_unit:UNIT

where

  gdsscale64.exe         path/name of the executable

  input_file           path/name of the gdsii input file

  output_file          path/name of the new gdsii file to create

  -xform:list          physical transform directive

  -outunit:UNIT        units of output file: UM, MM, MIL, INCH
  
  -outgrid:0.0001      Specify grid of output file to be 10000
  

The Transform Parameter List

If the -xform: directive is used it must be followed by a list of parameters in this order:

-xform:anchor_x, anchor_y, rotation(ccw), mirror_x, mirror_y, scale_x, scale_y, offset_x, offset_y

The order of transformation is as follows:

1. mirror
2. rotation
3. scale
4. offset

Any scaling due to the outunit: directive is done last.

Example

We start with a simple GDSII file called: test_pattern_for_transform.gds that you can see below. We then run it through GDSSCALE with different parameters in the -xform directive.

Now we will run this file through gdsscale with different transformations.

MirrorX

gdsscale64.exe "%CD%\test_pattern_for_transform.gds" "%CD%\mirrorX.gds" -xform:0,0,0,1,0,1,1,0,0

MirrorY

gdsscale64.exe "%CD%\test_pattern_for_transform.gds" "%CD%\mirrorY.gds" -xform:0,0,0,0,1,1,1,0,0

Rotate 270

gdsscale64.exe "%CD%\test_pattern_for_transform.gds" "%CD%\rotate270.gds" -xform:0,0,270,0,0,1,1,0,0

Rotate 270 + MirrorX

gdsscale64.exe "%CD%\test_pattern_for_transform.gds" "%CD%\rotate270_mirrorX.gds" -xform:0,0,270,1,0,1,1,0,0