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Federal Circuit Affirms Use of Technical Advisor by District Court

April 11, 2002

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Last Month at the Federal Circuit - May 2002

Judges: Gajarsa (author), Newman, and Dyk (concurring)

In TechSearch v. Intel Corp., No. 00-1226 (Fed. Cir. Apr. 11, 2002), the Federal Circuit affirmed a district court’s grant of SJ of noninfringement in a patent case dealing with complex computer microprocessor technology.

A Complex Instruction Set Computer (“CISC”) architecture requires an extensive, fixed set of instructions in the logic of a CISC microprocessor. A Reduced Instruction Set Computer (“RISC”) architecture uses microinstructions to reduce the complexity of a RISC microprocessor. This reduced complexity allows a RISC microprocessor to execute instructions at significantly higher speeds than a CISC micropage processor.

TechSearch, L.L.C. (“TechSearch”) owns U.S. Patent No. 5,574,927 (“the ’927 patent”) directed to a RISC architecture computer (“RAC”) configured for emulation of the instruction set of a target computer (“target”). The RAC can run existing software written for targets, including CISC architecture computers.

Intel Corporation (“Intel”) manufactures an x86 series of CISC microprocessors, including, in chronological order of development, the 486, the P5, and the P6. The instruction set of each later microprocessor includes all of the instructions, without modification, of its immediate predecessor and some new instructions.

TechSearch sued Intel in the U.S. District Court for the Northern District of California, alleging infringement of the ’927 patent by the P6 microprocessor. Two of the three independent claims of the ’927 patent require the RAC to use two instruction sets—native and expanded. The instructions of the native set have a width of N bits, while the instructions of the expanded set have a width of M+N bits. The other independent claim requires both “a plurality of indirect registers pointing to emulated registers” and “processing said emulated registers with an arithmetic logic unit.”

After a Markman hearing, the district court had appointed a technical advisor (“TA”), employing procedural safeguards to ensure that the TA remained a neutral third party and limited his role to that of providing technical advice based upon the record and references standard in the field. The district court subsequently ruled that when not emulating a target, the RAC uses the N-bit, native-set instructions. And, when emulating a target, the RAC uses both M-bit portions and N-bit portions of the M+N bit expanded- set instructions. For a given expanded-set instruction, the district court concluded that its N-bit portion corresponds to a native-set instruction, while its M-bit portion redefines the N-bit portion, enabling the RAC to emulate the target. The district court also had interpreted the meaning of several other claim terms.

Both parties filed cross-motions for SJ. Finding multiple reasons why Intel’s P6 microprocessors did not infringe any independent claims of the ’927 patent, the district court granted Intel’s motion for SJ of noninfringement.

On appeal, the Federal Circuit limited its review of claim construction to those terms essential for disposition of the case, and the Court agreed with the district court as to the meaning of each such term. Regarding two of the independent claims, the Federal Circuit agreed that the P6 microprocessor could not infringe because it uses only one set of instructions with a fixed number of bits and because that set includes all of the instructions, without modification, of the P5 microprocessor. Regarding the third independent claim, the Court agreed that the claim’s express language prevented a finding of infringement, because in the P6 microprocessor at least two layers of registers exist between the alleged indirect registers and the alleged arithmetic logic unit. Thus, these indirect registers could not point to any registers that were themselves processed by this arithmetic logic unit.

In examining the role of the TA, the Federal Circuit noted that district courts possess the inherent authority to appoint a TA outside the purview of Rule 706 of the Federal Rules of Evidence. Therefore, agreeing with the district court’s claim construction and conclusions, and finding sufficient procedural safeguards regarding the TA, the Federal Circuit affirmed the district court’s grant of SJ of noninfringement.

In a concurring opinion, Judge Dyk voiced his concern that the district court’s judgment may have been too heavily influenced by the TA and, as a result, the district court may have resolved factual issues on SJ. However, he also pointed out that at least one ground, not implicating this concern, existed for a finding of noninfringement as to each asserted independent claim.