Introduction

The OASIS2GBR program converts OASIS or GDSII layout data into Gerber's RS274X format. It is very useful if your CAD tools create GDSII or OASIS and your mask writer accepts Gerber format.

oasis or gdsii to gerber flow

Basic Behavior

    The output Gerber units are always in units of MM no matter what the input units.

    Automatically recognizes whether input file is GDSII or OASIS

    The program interface is by command line

    All Gerber output is using the G36/G37 area fill command


Output File Optimizations

Directly converting OASIS/GDSII to Gerber can result in extremely large Gerber files which can slow down or crash even power RIPs. Therefore Artwork has implemented two major optimizations designed to reduce both the file size and increase the speed of the Gerber RIP. These are:

    Repetition

    Use of the Gerber SR command to take advantage of repeated data     Details ...


    Arc/Circle Recognition

    Recognizing a series of short segments as an arc and creating arc data or round flashes in Gerber.     Details ...


Command Line Syntax

The the library is managed using the gbrxtrakapp64.exe executable. This executable takes the command line arguments and converts them into library calls the run the conversion.


gbrxtrakapp64.exe <input_oasis_file> <output_gerber_file> [OPTIONS]

where

<input_oasis_file>                    Path/filename of the OASIS or GDSII 
                                      file to be translated.

<output_gerber_file>                  Path/filename of the translated GERBER output.


[OPTIONS]

-layers:<list>                        Comma separated list of layers of interest
                                      if -layers is not present all layers will be merged

-cell:<name>                          Set the specified cell as the view cell for extraction.
                                      if no -cell is present the program will choose the top 
                                      cell automatically.          

-window:<minX>,<minY>,<maxX>,<maxY>   Extract data from the specified window

-nocompress                           Disable compression; default behavior is -compress which
                                      will use SR and arc recovery to minimize output file size.

-mode: compact | speed                Determines which compaction algorithm to use
                                      default is -mode:speed

-log:<log_file>                       Write log to this file

-silent                               Suppress stdout messages

-overlap:overlap_in_file_units        to specify amount of overlap between butting polygons.

-circularize:max_chord_error          parameter to control the arc recovery process.
                                      if this value=0 then arc recovery is disabled.

-revalidate                           re-validates (post overlap) output polygons 
                                      and fixes any polygon considered to be illegal. 

-format:XY                           Specify the number of integer and decimal 
                                     places for co-ordinate data along both X,Y 
                                     axes. X is the number of integer digits and 
                                     Y is the number of decimal digits.


Command Line Examples

Create data for all layers using the default top cell from an OASIS/GDSII file

gbrxtrakapp64.exe sample_input.gds  sample_output.gbr

This will produce a RS274X file for each layer in the layout database since the -layer command line option was not used.


Faster conversion as oppose to compact output file

gbrxtrakapp64.exe sample_input.gds sample_output.gbr -mode:speed

This option checks the input file for hierarchy. If sufficient hierarchy is found, it uses an alternate algorithm and emphasizes speed over compaction. If sufficient hierarchy is not found, it uses the the original algorithm for superior compaction. -mode:compact uses the original algorithm and emphasizes compaction over speed.


Create Gerber files for all layers on a specific cell (TEST) from an OASIS/GDSII file

gbrxtrakapp64.exe sample_input.gds sample_output.gbr -cell:TEST


Create Gerber files for specific set of layers (1,2:2,3) from an OASIS/GDSII file

gbrxtrakapp64.exe sample_input.gds sample_output.gbr -layers:1,2:2,3

the -layers: argument enables the user to specify a list of layers or layers:datatype to output.


Turn off the repetition recognition algorithms

gbrxtrakapp64.exe sample_input.gds sample_output.gbr -nocompress

Writing a log file to disk

gbrxtrakapp64.exe sample_input.gds sample_output.gbr -log:sample.log

Suppressing messages to stdout

gbrxtrakapp64.exe sample_input.gds sample_output.gbr -silent

By default, OASIS2GBR will open a window and display progress messages. To suppress this behavior use the command line option: -silent.


Return Codes

If you wish to run the conversion from a script or batch it is useful to know that the program returns one of two return codes:

0 success 
1 failure Information about the cause of error is sent to stderr

Gerber Output Specification

The Gerber output format is the same no matter what the input units and resolution are.

    Zero Suppression: leading zeros omitted
    Format: of 3.5
    Units: MM

Geometry - How Holes/Islands are Handled

The default behavior is to create holes and islands using "cut lines" often referred to as keyhole geometry. This page describes in detail what the output geometries look like and discusses possible options if the current approach causes problems for the mask writer.

example of a reentrant polygon (keyholed) generated to support island or hole.


Platform and Operating System

Windows

64 bit Windows 7/8/10

 

Linux

64 bit RHEL 5 or higher




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Revision History

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ARTWORK CONVERSION SOFTWARE, INC.                  Company Profile
417 Ingalls St.,     Santa Cruz, CA 95060         Tel (831) 426-6163     Fax 426-2824               email: info@artwork.com