Synopsys v. Siemens Industry Software: Federal Circuit Appeal Voluntarily Dismissed
Synopsys, Inc. and Siemens Industry Software Inc. jointly ended a Federal Circuit infringement appeal covering three EDA patents directed at fixing design requirement violations in multi-corner multi-mode scenarios. The parties agreed to dismiss under Fed. R. App. P. 42(b) with each side bearing its own costs — resolved in 256 days without any merits ruling.
A high-stakes EDA patent appeal ends by mutual agreement
Synopsys, Inc. filed this Federal Circuit appeal on 29 September 2023, asserting infringement of three United States patents — US8407655B2, US7853915B2, and US8234614B1 — each directed at electronic design automation (EDA) technology for fixing design requirement violations across multiple timing corners and operating modes. The accused product relates to multi-corner multi-mode (MCMM) design constraint resolution, a capability central to advanced semiconductor sign-off workflows. The defendant, Siemens Industry Software Inc., is a direct competitor in the EDA market through its Calibre and related toolchain offerings.
The appeal was terminated on 11 June 2024 when both parties jointly moved for dismissal under Federal Rule of Appellate Procedure 42(b). The court ordered the proceeding dismissed with each side bearing its own costs. Because the dismissal was voluntary and no merits ruling was issued, the Federal Circuit made no determination on infringement, validity, or claim construction. The absence of a cost-shifting award is consistent with a negotiated resolution rather than a capitulation by either side.
The 256-day duration is relatively short for a Federal Circuit appeal, suggesting the parties may have reached a commercial or licensing resolution before full merits briefing concluded — though the public record is silent on any underlying terms. The simultaneous agreement of both parties to bear their own costs typically signals a negotiated exit. Whether any cross-licensing, design-around, or settlement payment accompanied the dismissal remains unknown from publicly available filings.
Filing to Voluntary dismissal in 256 days
256 days — resolved before full Federal Circuit briefing cycle typically concludes
Appeal dismissed by agreement: what the Rule 42(b) order means for both parties
Fed. R. App. P. 42(b) dismissal: no merits adjudication
Rule 42(b) allows parties to stipulate dismissal of a federal appellate proceeding at any time. Because both sides agreed, the Federal Circuit issued no opinion on infringement, validity, or claim scope. The underlying district court record — including any claim construction, summary judgment, or jury findings — remains the last substantive word, but is not affirmed or endorsed by the appellate court.
Procedural exit — no precedential rulingPublic record is silent on prejudice terms
The order states only that the proceeding is dismissed under Rule 42(b). The public filing does not specify whether the dismissal is with or without prejudice to re-filing or re-assertion. In appellate practice, a Rule 42(b) dismissal typically forecloses re-appeal of the same lower court judgment, but the parties may have agreed to separate terms governing any future enforcement or licensing activity. IP professionals should not assume finality on the merits from this order alone.
Prejudice status: unspecified in public recordSynopsys exits appeal without a Federal Circuit win — or loss
Synopsys initiated the appeal, meaning it was the party seeking reversal or modification of a lower court outcome. Agreeing to voluntary dismissal before a merits decision suggests it either secured adequate relief through negotiation or assessed the appellate risk as unfavourable. The three asserted patents remain in Synopsys’s portfolio, but their enforceability against Siemens in this context is now governed by whatever was agreed privately, not a court ruling.
Patents survive; enforcement terms undisclosedEDA sector: MCMM constraint IP tension unresolved by courts
The dismissal leaves multi-corner multi-mode design constraint technology without a Federal Circuit precedent on these specific patents. Competitors developing or marketing MCMM timing closure or design-rule fixing tools cannot rely on this outcome as clearance. The patents remain active in Synopsys’s enforcement arsenal, and the sector-wide question of where the claim boundaries lie in MCMM EDA workflows is unanswered by this proceeding.
No MCMM EDA claim-scope precedent setFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Synopsys, Inc. | Company | EDA software company — holder of US8407655B2, US7853915B2, and US8234614B1Search in Eureka ↗ |
| Defendant | SIEMENS INDUSTRY SOFTWARE INC. | Company | EDA and industrial software division of Siemens AG, competing in semiconductor design toolsSearch in Eureka ↗ |
| Plaintiff counsel | Amelia A. DeGory | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff counsel | David B. Cochran | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Emily C. Towers | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Gregory A. Castanias | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Joshua R. Nightingale Esq. | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Matthew J. Silveira | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Matthew Johnson | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Robert Breetz | Attorney | Counsel for Synopsys, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Jones Day | Law Firm | Representing Synopsys, Inc.Search in Eureka ↗ |
| Defendant counsel | Andrew M. Mason | Attorney | Counsel for SIEMENS INDUSTRY SOFTWARE INC.Search in Eureka ↗ |
| Defendant counsel | John D. Vandenberg | Attorney | Counsel for SIEMENS INDUSTRY SOFTWARE INC.Search in Eureka ↗ |
| Defendant counsel | Sarah Elisabeth Jelsema | Attorney | Counsel for SIEMENS INDUSTRY SOFTWARE INC.Search in Eureka ↗ |
| Defendant law firm | Klarquist Sarkman LLP | Law Firm | Representing SIEMENS INDUSTRY SOFTWARE INC.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The order’s phrasing — ‘The parties having so agreed’ — confirms this was a bilateral, consensual exit rather than a unilateral withdrawal. Fed. R. App. P. 42(b) requires either court order or stipulation of all parties, and the mutual cost-bearing term reinforces parity. No infringement finding, validity ruling, or claim construction was issued. The Federal Circuit’s role was purely administrative: recording the parties’ agreed outcome. Neither party can cite this order as precedential authority on the merits of the asserted MCMM EDA patents.
US8407655B2, US7853915B2 & US8234614B1 — MCMM EDA constraint violation fixing
The three patents — US8407655B2, US7853915B2, and US8234614B1 — each address a distinct aspect of multi-corner multi-mode (MCMM) design constraint management in electronic design automation. MCMM methodology allows semiconductor designers to validate and fix timing and design-rule violations simultaneously across multiple process, voltage, and temperature corners and operating modes, reducing sign-off iteration cycles. The application numbers (12/949689, 12/145405, 12/156963) indicate filings in the 2008–2010 window, placing their priority in an era when advanced node MCMM complexity was rapidly increasing.
For the EDA sector, these patents sit at the heart of timing closure workflows used in tape-out of advanced semiconductor devices. Synopsys’s PrimeTime platform has long been a market leader in MCMM sign-off; these patents may underpin proprietary algorithmic approaches to constraint violation resolution. With Siemens’s Calibre and related tools competing directly in the physical verification and sign-off space, the commercial stakes of defining the claim boundaries on MCMM constraint fixing are significant for any third-party EDA vendor or fabless semiconductor company building or licensing similar capabilities.
Should your EDA tool or design flow be cleared against these three patents?
Any company developing or deploying EDA tools with MCMM timing analysis, constraint violation fixing, or multi-scenario sign-off capabilities should treat US8407655B2, US7853915B2, and US8234614B1 as active FTO considerations. The patents were litigated to the Federal Circuit level, confirming Synopsys’s willingness to enforce. The dismissal provides no safe harbour — no claim was held invalid or not infringed. R&D teams building AI-assisted or automated timing closure tools face particular exposure as MCMM functionality becomes more embedded in sign-off automation.
PatSnap Eureka’s FTO Search Agent can map the full claim scope of each of these three patents, identify continuation and divisional family members that may extend protection, and flag overlapping prior art that could inform a validity challenge or design-around strategy. For in-house IP teams at EDA vendors or large fabless semiconductor companies, Eureka can also track Synopsys’s broader MCMM-related portfolio to identify enforcement trends before they reach the docket.
Run a freedom-to-operate analysis on US8407655B2 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit EDA and semiconductor IP appeals
Related Federal Circuit appeals involving electronic design automation patents and MCMM timing analysis technology, including other Synopsys and Siemens EDA enforcement actions.
What this case signals for the EDA and semiconductor IP landscape
A voluntarily dismissed Federal Circuit appeal over MCMM EDA patents leaves meaningful uncertainty for EDA tool developers and semiconductor design teams.
Three active EDA patents remain enforceable after this dismissal
US8407655B2, US7853915B2, and US8234614B1 cover MCMM design constraint violation fixing — a capability embedded in advanced sign-off flows. No court has invalidated or narrowed these claims. Any EDA vendor or in-house team relying on similar methods should treat these patents as live enforcement risk and conduct a formal FTO review.
Mutual cost-bearing is a classic signal of a negotiated commercial exit
When both parties in an appellate infringement dispute agree to bear their own costs, it typically suggests neither side extracted a clear litigation win. This pattern is consistent with a licensing agreement, cross-licence, or business arrangement reached outside the docket. IP teams tracking competitive dynamics between Synopsys and Siemens should monitor subsequent licensing disclosures or product announcements.
Synopsys v SIEMENS — key questions answered
The Federal Circuit appeal was voluntarily dismissed under Fed. R. App. P. 42(b) on 11 June 2024, by agreement of both parties. No merits ruling on infringement or validity was issued. Each side bore its own costs. The three asserted EDA patents — US8407655B2, US7853915B2, and US8234614B1 — remain active in Synopsys’s portfolio.
Synopsys asserted US8407655B2 (application 12/949689), US7853915B2 (application 12/145405), and US8234614B1 (application 12/156963). All three cover technology related to fixing design requirement violations in multi-corner multi-mode (MCMM) scenarios in electronic design automation workflows.
No. A Rule 42(b) appellate dismissal is purely procedural and conveys no ruling on patent validity or infringement. The Federal Circuit did not adjudicate the merits. The three MCMM EDA patents remain valid and enforceable on their face, and the dismissal cannot be cited as precedent for invalidity or non-infringement.
In Federal Circuit practice, the default on voluntary dismissal may involve cost-shifting to the dismissing party. A mutual agreement that each side bears its own costs suggests a negotiated, bilateral exit — neither party obtained a cost award. This phrasing is commonly associated with settlements or licensing resolutions, though the public record does not confirm any such arrangement in this case.
Multi-corner multi-mode (MCMM) methodology is foundational to advanced semiconductor sign-off, enabling simultaneous validation across process, voltage, and temperature variations. Patents covering MCMM constraint violation fixing are strategically valuable because they may cover capabilities embedded in widely-used sign-off platforms. Enforcement of such patents directly affects EDA tool vendors and fabless semiconductor companies relying on MCMM-based timing closure flows.
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