RNS Number:7921S
Wolfson Microelectronics PLC
03 December 2003



3 December 2003

Immediate Release

                          Wolfson Microelectronics plc

  Initial Response to Cirrus Logic's Allegations filed with District Court in
                                California, USA

Wolfson Microelectronics plc ("Wolfson") has provided its initial response to
the patent infringement allegations lodged by Cirrus Logic Inc. ("Cirrus") with
the U.S. District Court in California, USA, and the U.S. International Trade
Commission (ITC).  On December 2, 2003, Wolfson filed papers in the California
District Court stating it does not infringe the two patents asserted by Cirrus,
and claiming that both of the patents are invalid.

Wolfson also has filed counterclaims against Cirrus for improperly interfering
with its Initial Public Offer on the London Stock Exchange and with its
customers, because Wolfson contends that Cirrus knew the patent being asserted
with the ITC and with the District Court was invalid.

Wolfson has provided Cirrus and the ITC with a paper written by two of the named
inventors of the patent being asserted with the ITC. This paper, which disclosed
the claimed subject matter of the patent, was published in November 1994, almost
three years before the patent was filed. Wolfson understands that the
publication of this paper constitutes prior art to the patent under U.S. Patent
law. Prior art that describes what is claimed to be the novel subject matter in
a patent will render that patent invalid. Further, Cirrus failed to inform the
U.S. Patent Office about this paper when it applied for the patent.  Failure to
tell the Patent Office about the paper, and the paper's relevance, may alone
make the patent unenforceable.


Enquiries


Wolfson                                                           0131 272 7000

Jim Reid, CTO
George Elliott, CFO

Brunswick                                                         020 7404 5959

Tom Buchanan
Harry Chathli




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