Oasis Tooling Inc v. Siemens Industry Software Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Oasis Tooling, Inc. (Delaware)
  • Defendant: Siemens Industry Software, Inc. (Delaware)
  • Plaintiff’s Counsel: Potter Anderson & Corroon LLP; Kramer Levin Naftalis & Frankel LLP
• Case Identification: 1:22-cv-00151, D. Del., 02/01/2022
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because the Defendant is a Delaware corporation incorporated within the district.
• Core Dispute: Plaintiff alleges that Defendant’s Calibre Design Solutions software suite infringes patents related to methods and systems for analyzing semiconductor chip design files to verify cell integrity and origin.
• Technical Context: The technology lies in the field of Electronic Design Automation (EDA), specifically tools that automate the verification of complex integrated circuit designs before the costly manufacturing process.
• Key Procedural History: The complaint alleges that Defendant had pre-suit knowledge of the asserted patents through a former Oasis employee who joined Mentor Graphics (later acquired by Siemens) and through direct business discussions in 2013, during which Oasis provided Mentor Graphics with technical white papers and an evaluation copy of its own patented software. Siemens acquired Mentor Graphics in 2017.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,266,571 - "Methods and Devices for Independent Evaluation of Cell Integrity, Changes and Origin in Chip Design for Production Workflow," Issued Sep. 11, 2012

The Invention Explained

• Problem Addressed: The patent describes the difficulty in tracking the integrity and versioning of the thousands of individual design components ("cells") used in a complex integrated circuit design (Compl. ¶17; ’571 Patent, col. 1:47-2:4). Conventional tools operating at the file level were ineffective at identifying functionally equivalent cells that were described differently or ensuring that the most up-to-date cell versions were being used across different design files and formats (’571 Patent, col. 2:5-34).
• The Patented Solution: The invention provides a method for granular analysis of design data by first parsing the data and organizing it into a standardized "canonical form," a process that reduces sensitivity to non-functional variations like comments or formatting (Compl. ¶16; ’571 Patent, col. 3:6-14). From this canonical form, a unique digital fingerprint or "digest" is generated for each cell. By comparing these digests from different design files (e.g., a new design versus an approved library), engineers can automatically and reliably identify similarities, differences, or the use of unauthorized or obsolete cells (’571 Patent, Fig. 5; col. 6:15-21).
• Technical Importance: This approach enables a new level of automated, cell-level auditing in the semiconductor design workflow, improving reliability and preventing costly errors that might arise from using incorrect or modified design components (’571 Patent, col. 2:62-67).

Key Claims at a Glance

• The complaint asserts independent claims 1 (method) and 16 (computer-readable medium) (Compl. ¶49).
• Independent Claim 1 recites a computer-implemented method with the essential elements:
  • Identifying cells within design data files.
  • Parsing the syntax of and normalizing the design data within the cells into canonical forms to reduce sensitivity to non-functional variations.
  • Partitioning functionally significant design data from non-significant data within the canonical forms.
  • Calculating and storing digests of the cells that include at least the functionally significant data.
  • Comparing the digests of cells in at least two design data files.
  • Summarizing results of the comparison.
• Independent Claim 16 recites a non-transitory computer-readable storage medium containing code for a system with modules that largely mirror the steps of claim 1, including a parser, normalizer logic, partitioning module, canonical forming module, digester, comparer, and reporter.

U.S. Patent No. 7,685,545 - "Methods and Devices for Independent Evaluation of Cell Integrity, Changes and Origin in Chip Design for Production Workflow," Issued Mar. 23, 2010

The Invention Explained

• Problem Addressed: The ’545 patent addresses the same technical problem as the ’571 Patent: the lack of robust, automated tools for tracking cell-level changes, verifying cell equivalence, and ensuring version integrity in complex semiconductor design workflows (Compl. ¶17; ’545 Patent, col. 2:5-34).
• The Patented Solution: The patented solution is likewise a system for granular analysis that involves parsing design data, normalizing it into a canonical form to eliminate non-functional differences, calculating a unique "digest" for each cell's canonical form, and comparing these digests to identify discrepancies between design files (’545 Patent, Abstract; col. 3:1-24).
• Technical Importance: The technology provides a systematic way to audit and validate the components of a chip design at a granular level, which was not available with conventional file-level differencing tools (’545 Patent, col. 4:5-10).

Key Claims at a Glance

• The complaint asserts independent claim 1 (method) and references claim 14 (apparatus) in its contributory infringement allegations (Compl. ¶71, ¶85).
• Independent Claim 1 recites a computer-implemented method comprising the key elements:
  • Identifying cells within design data files.
  • Parsing syntax of and normalizing the design data within the cells into canonical forms.
  • Calculating and storing digests of the cells.
  • Comparing the digests of cells in at least two of the design data files.
  • Summarizing the results of the comparison.

III. The Accused Instrumentality

Product Identification

• The complaint identifies the "Accused Products" as the Siemens Calibre Design Solutions suite, including specific modules and features such as the Calibre Physical Verification Platform, Calibre Pattern Matching, Calibre DBdiff, Calibre nmLVS, and the Auto-Waivers functionality (Compl. ¶33, ¶35, ¶41, ¶43).

Functionality and Market Context

• The Accused Products are described as a flagship EDA software suite used throughout the semiconductor industry for physical verification tasks such as Layout-vs.-Schematic (LVS) comparison, Design Rule Checking (DRC), and reliability verification (Compl. ¶33, ¶36, ¶37). The complaint alleges that specific functionalities, such as the DBdiff tool for identifying cell differences and the Auto-Waivers feature for managing design rule violations, perform infringing methods (Compl. ¶41, ¶43, ¶55). The Auto-Waivers process, for example, is alleged to involve comparing cells flagged for violations against a database of approved waived designs to identify applicable waivers and report remaining errors (Compl. ¶58). A screenshot in the complaint illustrates a user interface for this process that explicitly mentions "Checksum Annotation" (Compl. Ex. 18 at 1).

IV. Analysis of Infringement Allegations

’571 Patent Infringement Allegations

’545 Patent Infringement Allegations

Identified Points of Contention

• Scope Questions: A potential issue may be whether the "checksum" functionality alleged in the complaint (Compl. ¶56, ¶77) falls within the scope of the term "digest" as used in the patents. The defense may argue that "digest" implies a specific type of cryptographic hash (like MD5 or CRC, mentioned as examples in the patent specification) that a simple checksum does not satisfy (’571 Patent, col. 6:8-10).
• Technical Questions: The analysis may raise the question of whether the accused products' alleged removal of "non-functional variations" (Compl. ¶56) is technically equivalent to the claimed steps of "normalizing" and "partitioning." A defendant could contend that its process is a simple filtering step that does not produce a "canonical form" in the structured manner described in the patents, which includes partitioning data by layer and sorting order-independent elements (’571 Patent, Fig. 7).

V. Key Claim Terms for Construction

The Term: "digest"

• Context and Importance: This term is central to the infringement theory, as the complaint alleges that the accused products' "checksum" function is a "digest" (Compl. ¶56, ¶77). The construction of this term will determine whether the accused functionality can meet this key claim limitation.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification states that "A variety of hash functions can be used to create the digests, such as CRC, MD5 and others" (’571 Patent, col. 6:8-10). Because a Cyclic Redundancy Check (CRC) is a type of checksum, this language may support an interpretation that includes the accused functionality.
  • Evidence for a Narrower Interpretation: The patents describe the digest as being generated from a "canonical form" that results from parsing and partitioning (’571 Patent, col. 6:1-6). An argument could be made that a "digest" is not just any hash, but one specifically calculated on this specially processed data structure, potentially narrowing its scope.

The Term: "canonical form"

• Context and Importance: The invention's novelty is partly based on creating a "canonical form" to enable reliable comparisons. Whether the accused products' data processing creates such a form is a likely point of dispute.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The abstract broadly defines the purpose of canonical forms as to "reduce[] the sensitivity of data analysis to variations in data that have no functional impact on the design" (’571 Patent, Abstract). This purpose-driven definition could support a broader construction that covers any method achieving that goal.
  • Evidence for a Narrower Interpretation: The detailed description provides specific examples of creating canonical forms, such as separating data by layer, distinguishing between geometric and non-geometric data, and sorting order-independent elements (’571 Patent, col. 7:26-31, col. 8:1-3). A narrower construction might require the performance of these specific, more complex normalization steps.

VI. Other Allegations

Indirect Infringement

• The complaint alleges induced infringement, stating Siemens instructs and encourages customers to use the accused features through user manuals, white papers, online support communities, and consulting services (Compl. ¶63, ¶65-67). It also alleges contributory infringement on the basis that the accused software is not a staple article of commerce and, when installed, necessarily includes the claimed modules for performing the infringing methods (Compl. ¶64, ¶85).

Willful Infringement

• Willfulness is alleged based on pre-suit knowledge dating back to 2013, when Oasis allegedly provided Siemens’ predecessor, Mentor Graphics, with technical documents and an evaluation copy of its own software which included a patent marking statement (Compl. ¶27-29). The complaint also asserts knowledge via a former Oasis employee who later joined Mentor Graphics (Compl. ¶23-26). Continued infringement after the filing of the complaint is also cited as a basis for willfulness (Compl. ¶47).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of definitional scope: can the term "digest," which the patent illustrates with examples like CRC and MD5, be construed to cover the "checksum" functionality that the complaint alleges is used in the accused waiver management and database-differencing tools?
• A key evidentiary question will be one of technical operation: does the accused products' method of removing "non-functional variations" like comments and spaces result in a "canonical form" as required by the claims, or do the patents demand a more complex data restructuring (such as sorting or layer-based partitioning) that the accused products do not perform?