GDSFILT is a general purpose utility for manipulating GDSII stream data. It enables a mask designer to export a new GDSII file, defined by filters, e.g. layer or datatype, into a new smaller file. GDSFILT can also flatten a file, prune off empty structures and even filter output entities by size and shape!

GDSFILT can be used to combine multiple GDSII files into a single larger one. It has different modes for merging files -- either preserving all structures (even those with the same name) or by replacing data in a structure will that of the merged file.

Features and Functions

Extract by Layer - use this function to extract data on specified layers and/or datatypes. You can preserve the database hierarchy or flatten it.

Extract by Structure - use this to extract a structure (and its children) from a large file.

Prune Empty Structures - use this to search through a large GDSII file and to delete (prune) any structure defintions that are empty of entity data or which are not referenced.

Fix Names - have GDSFILT scan all structure names and fix any that can cause problems. Converts all names to either upper or lower case as needed. Finds illegal characters in name strings and replaces them.

Merge Multiple Files - use this to combine or merge two or more GDSII files. There are multiple sub-options on how the hierarchy should be merged.

Filter by Entity Size & Shape - use this option to filter entities out by their size and shape. For example, extract out the die pad openings from a very large M1 layer.

GSCAN - use this get a list of all structures, hierarchy and layers/datatype that contain entities. Useful for knowing the basics of a GDSII file.

Fix Paths - use this option to find any 0 width paths and reset their width. Find any paths that fold onto themselves (creating a self-intersecting area) and repair them.

Application Notes

how to rename structures (cells) using the -rename command line option.

Describes how to directly run the gdsfilt engine, gdsfilte, from the command line.

Describes how to merge several GDSII files into a single one using the Add option

Describes how to take a large chip design and extract just the pad ring layer (simultaneously flattening the output data) so that the pad openings can be easily imported into Cadence APD.

Describes how to use gdsSetUnits to change the units and resolution of a GDSII file.

Describes how to use the polygon filter add-on to filter by boundary size and shape. Ideal for extracting pad openings from a top metal layer. Flip Chip Designers may be very interested in this...

Describes how to use a redirection file instead of a long command line -- useful when merging or adding many files together.

Describes how to use the layer extraction, cell rename, flatten output and file merge using gdsfilt script.

Describes how to add multiple GDSII files to one output file in batch mode on Windows.

How to remove cells (using wildcards) that contain only dummy fill ...

GDSFILT hangs during scanning when TMPDIR is not defined...