Being able to compare the received layout with the reference design is a critical step in photolithography mask generation. Unfortunately, until now, this is achieved by XORing the files, a time consuming operation which requires access to both files.

As exchanges of layout descriptions between teams involved in modern integrated circuit (IC) development and production increase in terms of rate, value, and size, it becomes critical to implement a secure, reliable, and efficient information exchange flow between collaborating companies and teams.

Layout database comparator

  • Security and traceability in photolithography mask generation
  • Geometry-based signature
  • Ultra-fast signature comparison
  • Intellectual property protection
  • High performance XOR
  • Parallelism computation for unsurpassed performance
  • Client/server mode for GUI customization

secure photolithography mask data prep

Geometry-based signature

Based on XYALIS’ patent, GOTdiff captures the geometry of each layer in the design to generate a unique geometry-based signature file, independent of the layout file format and/or design description strategy.

Signature-based comparison

GOTdiff quickly compares the signatures of 2 layout files. Either by re-using an already computed signature, or by generating it from the layout database. An optional detailed XOR is performed only on the windows showing differences in case of mismatch between signatures.

Intellectual property protection

By limiting the transfer to a geometry-based signature file instead of the full reference design, reduces the risk of unnecessary intellectual property dissemination.  

High performance XOR

GOTdiff benefits from the advanced GDSII & OASIS ® TOOL (GOT) data representation engine developed by XYALIS in order to XOR the largest layout files in a minimum computing time with minimum disk and memory requirements.
GOTdiff directly works on compressed GDSII and OASIS ® files to further improve speed and memory consumption.

Layout integrity control for photolithography masks

Layout file integrity can be easily validated by comparing the database with a signature file sent separately. This can be done even if the database has been converted into a different format or simply read/rewritten by any CAD tool.
For a simple Go/No Go comparison, it is useless to retrieve the original database: only the small signature file is required.

Error file generation

GOTdiff generates GDSII or OASIS ® layout files of the differences identified by the XOR operation. Differences can also be saved in a DRC-compliant error file.

Heavy parallelism computation for unsurpassed performance

In order to reduce photolithography mask data preparation cycle time, GOTdiff optimizes the size of the computation window to maximize parallel distribution across processors.

Client / server mode

GOTdiff includes a distant access mechanism based on HTTP sockets, which allows for client/server access from any web interface. This mechanism can also be used to develop a custom graphical user interface.

Read more in the Tech Design Forum article.


GOTdiff is dedicated to layout database comparison and security

  • Layout integrity control
  • Intellectual property protection
  • Speed up layouts comparison
  • Speed up new standards migration



  • Geometry-based signature
  • Ultra-fast signature comparison
  • Intellectual property protection
  • High performance XOR
  • Parallelism for unsurpassed performance
  • Client/server mode for GUI customization
  • File control
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