PTAB

IPR2025-00417

SAP America Inc v. Valtrus Innovations Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Snoop Filter for a Multi-Processor-Bus Computer System
  • Brief Description: The ’409 patent discloses a computer system architecture designed to manage memory coherency in a multi-processor environment. The system uses a coherency control module that acts as a snoop filter to minimize the clock cycles required to obtain cache state information and determine the proper snoop response on processor or input/output (I/O) buses.

3. Grounds for Unpatentability

Ground 1: Claims 1-4, 7-12, and 15-17 are obvious over Khare.

  • Prior Art Relied Upon: Khare (Patent 6,487,643)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Khare, which discloses a multi-node architecture for managing memory requests, teaches every limitation of the challenged claims. Petitioner asserted that Khare’s multi-node system corresponds to the claimed "computer system." The "switching agent 140" in Khare was argued to be the claimed "coherency control module," and its internal components were mapped to the claimed sub-modules. Specifically, Khare's "request manager 141" was mapped to the "request module," the "pending requests buffers" (145, 146, 147) were mapped to the "active snoop queue (ASQ) module," and the "memory manager 149" with its associated "table 143" was mapped to the "static RAM interface module" configured to access an "address look-up table." Petitioner further contended that Khare’s combination of main memory (DRAM) and processor caches (SRAM) teaches the claimed RAM with static and dynamic portions.

Ground 2: Claims 5-6 and 13-14 are obvious over Khare in view of Kirkman.

  • Prior Art Relied Upon: Khare (Patent 6,487,643) and Kirkman (Patent 6,581,063).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the teachings of Khare as established in Ground 1. Petitioner argued that while Khare taught the use of "list structures" (its pending request buffers) to manage memory access requests, it did not specify their exact implementation. Claims 5, 6, 13, and 14 add limitations requiring these list structures to be "two-dimensional doubly-linked lists with head and tail pointers" and to comprise "dependency links." Petitioner asserted that Kirkman, which teaches methods for maintaining linked lists in software, supplied these missing details. Kirkman explicitly described the implementation and benefits of doubly-linked lists, including the use of head/tail pointers and orthogonal structures that create dependencies between lists.
    • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would combine these references for predictable results. A POSITA implementing the request management system of Khare, which can be software-based, would be motivated to use a well-known and efficient data structure to manage the request lists. Kirkman taught that doubly-linked lists were a common and efficient solution for such tasks, allowing for optimized insertion, searching, and removal of list entries. Therefore, a POSITA would combine Kirkman's efficient data structure with Khare’s system to improve the performance of Khare's cache-coherence engine.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in this combination. The problem of managing lists of requests was well-understood, and using a doubly-linked list, as taught by Kirkman, was a standard and predictable solution. Integrating this known software structure into Khare's system to realize the benefits of efficient list management would have been a straightforward implementation for a POSITA.

4. Arguments Regarding Discretionary Denial

  • §325(d): Petitioner argued that discretionary denial under §325(d) was not warranted because the primary references, Khare and Kirkman, were not cited or considered by the examiner during the original prosecution of the ’409 patent. Therefore, the arguments and art presented in the petition were not cumulative to those previously evaluated by the USPTO.
  • §314(a) (Fintiv Factors): Petitioner contended that the Board should not exercise discretionary denial under Fintiv. The core arguments were that the petition presented compelling merits, and the factors weighed against denial. Petitioner asserted that the trial date in the parallel district court litigation was unreliable due to pending motions challenging the patent owner's standing. Further, Petitioner stipulated that if the inter partes review (IPR) was instituted, it would not pursue the same invalidity grounds in the district court, thus mitigating concerns about overlapping issues and duplicative efforts.

5. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 1-17 of Patent 6,823,409 as unpatentable under 35 U.S.C. §103.