Acquisition Will Expand Market-leading DesignWare IP Solution to
Include Comprehensive Chip Infrastructure, Embedded Memory and
Connectivity IP

MOUNTAIN VIEW & SUNNYVALE, Calif.–(BUSINESS WIRE)–Feb. 23,
2004–

Synopsys, Inc. (Nasdaq:SNPS), the world leader in semiconductor
design software, today announced two acquisitions that will expand the
company’s successful DesignWare(R) portfolio of standards-based IP.
These acquisitions will help deliver the comprehensive on-chip
building blocks designers need to build the complex systems-on-chips
(SoCs) used in today’s consumer product, storage and network
infrastructure markets. Synopsys and Monolithic System Technology,
Inc. (MoSys); (Nasdaq:MOSY), a leading provider of high-density SoC
embedded memory solutions, today announced that they have entered into
a definitive agreement for Synopsys to acquire MoSys in a cash and
stock transaction valued at approximately $432 million (approximately
$346 million net of cash). The acquisition is expected to close before
the end of May 2004. In addition, Synopsys announced that has acquired
Accelerant Networks, a privately held company providing a highly
efficient technology for high-speed serial interfaces.

“As SoC complexity continues to increase, larger and larger parts
of the chip will be delivered as pre-designed, pre-verified IP
blocks,” said Aart de Geus, chairman and CEO of Synopsys. “Synopsys’
acquisition of MoSys and Accelerant will expand our IP portfolio to
provide a comprehensive offering of standards-based IP, chip
infrastructure IP and embedded memory IP. This important step puts us
at the forefront of the market in helping to deliver the integrated
solutions our customers need to reduce their manufacturing risk and
lower the cost of design for high-performance chips.”

MoSys Acquisition

The amount of embedded memory used on a chip is expected to
continue to grow dramatically in the next few years, from consuming
more than 50 percent of the die area today to 70 percent by 2005, and
up to 90 percent by 2011. This strong growth is being driven by an
increase in the development of integrated applications such as
consumer electronics that combine voice, data and multimedia on one
SoC. Adding MoSys’ unique, patented 1T-SRAM technology to Synopsys’
DesignWare IP portfolio will provide Synopsys customers with memory IP
that works with regular digital processes to offer a combination of
high density, low power consumption, high speed and low cost that
other available memory technologies do not match.

“MoSys and Synopsys share a common goal of making it as easy as
possible for engineers to adopt and use IP so that they can focus on
their value-added technology,” said Fu-Chieh Hsu, president, CEO and
chairman of the Board for MoSys. “Through this acquisition, all SoC
designers will be able to readily take advantage of our patented
embedded memory technologies that deliver substantial benefits in
density, power, cost and performance for their end products. We
believe that this acquisition will provide added value for MoSys
investors and I invite them to join me on the Synopsys conference call
scheduled for today at 2:00 p.m. Pacific Time for additional details
of this transaction.”

The acquisition will be effected by means of an exchange offer to
acquire all of the outstanding shares of MoSys for a purchase price of
$13.50 per share, half of which is payable in Synopsys common stock
and half in cash. Synopsys has the option, exercisable not less than
two business days before expiration of the offer, to pay the entire
purchase price in cash. The acquisition is subject to certain
conditions, including the tender of a specified number of the shares
of MoSys, receipt of regulatory approvals, and other customary
conditions. Synopsys intends to assume all outstanding MoSys stock
options in the transaction. The boards of directors of both companies
have approved the transaction. In addition, certain of MoSys’
shareholders, including its executive officers and directors, who
collectively own approximately 29 percent of the outstanding shares of
MoSys, have agreed to tender their shares to Synopsys in the
transaction.

Accelerant Acquisition

Accelerant’s intelligent high-speed 6.25Gb/s CMOS transceivers
enable up to a ten-fold increase in data rates on the installed copper
backplanes and cable systems used in today’s server, storage,
enterprise and network transport applications. Synopsys intends to
apply Accelerant’s unique, proven SERDES (serializer-deserializer)
technology to offer multiple standards-based PHY cores such as PCI
Express, Serial ATA (SATA), and emerging 6.25 to 10Gb/s backplane
applications that utilize Accelerant’s leadership in both binary and
PAM4 (pulse amplitude modulation) signaling. By combining these
SERDES-based cores with Synopsys’ complementary digital cores,
Synopsys will be able to offer customers low-risk, integrated analog
and digital IP solutions.

“Accelerant’s underlying technology for high-speed serial
interfaces is complementary with Synopsys’ digital logic cores,” Ken
Molitor, president and CEO of Accelerant. “Through this acquisition,
Accelerant’s technology will be available to the broad range of ASIC,
FPGA and discrete silicon suppliers that system vendors require for
their high-volume cost-effective applications. The security of
integrated high-performance solutions from a trusted full-line
provider like Synopsys also helps reinforce standards-based
applications that can benefit from our technology.”

The terms of the acquisition were not disclosed.

Key Foundry Support

“TSMC has long held collaborative relationships with Synopsys and
MoSys,” said Dr. Genda Hu, vice president, Marketing, TSMC. “This
acquisition will further strengthen that relationship and benefit our
mutual customers going forward.”

Conference Call Open to Investors

Synopsys will disclose additional information about these
acquisitions in its quarterly earnings call being held today at 2:00
p.m. Pacific Time. A live webcast of the call will also be available
through a link at Synopsys’ web site at
http://www.synopsys.com/corporate/invest/invest.html. A recording of
the call will be available by calling 1-800-475-6701 (320-365-3844 for
international callers), access code 720419, beginning at 5:30 p.m.
Pacific Time today. A webcast replay will be available at
http://www.synopsys.com/corporate/invest/invest.html beginning from
approximately 5:30 p.m. Pacific Time today through the time of the
announcement of the Company’s results for the second quarter of fiscal
2004 in May 2004. The information provided on the earnings call will
be accurate only as of that time, and Synopsys undertakes no
responsibility for providing updated information.

Forward-Looking Statements

This press release contains forward-looking statements within the
meaning of the safe harbor provisions of Section 21E of the Securities
Exchange Act of 1934, including statements regarding the expected
benefits of the MoSys and Accelerant acquisitions and the anticipated
time of completion of the MoSys acquisition. These statements are
based on Synopsys’ current expectations and beliefs. Actual results
could differ materially from the results implied by these statements.

Factors that may cause or contribute to such differences include,
but are not limited to: the risk that the conditions to the MoSys
acquisition set forth in the acquisition agreement will not be
satisfied, in which case the acquisition may not close; changes in
MoSys’ businesses during the period between now and the closing;
developments in obtaining regulatory approvals for the transaction,
which may delay or prevent the closing; the successful integration of
MoSys’ and Accelerant’s operations and products into Synopsys’
business; competition in the market for IP; the ability to retain key
management and technical personnel of MoSys and Accelerant; and
unanticipated adverse reactions to the proposed transaction by
customers. For further discussion of these and other factors that may
cause results to differ from those discussed in this release, readers
are referred to documents Synopsys and MoSys have filed with the
Securities and Exchange Commission, specifically the section contained
in Part III, Item 7 of Synopsys’ Annual Report on Form 10-K for the
fiscal year ended October 31, 2003 filed with the SEC on January 29,
2004 entitled “Factors That May Affect Future Results” and the Section
contained in Part I, Item 2 of MoSys’ Quarterly Report on Form 10-Q
for the fiscal quarter ended September 30, 2003 filed with the SEC on
November 13, 2003 entitled “Risk Factors.” Synopsys and MoSys are
under no obligation to (and each expressly disclaims any such
obligation to) update or alter these forward-looking statements
whether as a result of new information, future events or otherwise.

About Synopsys

Synopsys, Inc. (Nasdaq:SNPS) is the world leader in electronic
design automation (EDA) software for semiconductor design. The company
delivers technology-leading IC design and verification platforms, and
IC manufacturing software products to the global electronics market,
enabling the development and production of complex systems-on-chips
(SoCs). Synopsys also provides intellectual property and design
services to simplify the design process and accelerate time-to-market
for its customers. Synopsys is headquartered in Mountain View, Calif.
and has offices in more than 60 locations throughout North America,
Europe, Japan and Asia. Visit Synopsys online at
http://www.synopsys.com/.

About MoSys

Founded in 1991, MoSys (Nasdaq:MOSY), develops, licenses and
markets innovative memory technologies for semiconductors. MoSys’
patented 1T-SRAM technologies offer a combination of high density, low
power consumption, high speed and low cost unmatched by other
available memory technologies. The single transistor bit cell used in
1T-SRAM memory results in the technology achieving much higher density
than traditional four or six transistor SRAMs while using the same
standard logic manufacturing processes. 1T-SRAM technologies also
offer the familiar, refresh-free interface and high performance for
random address access cycles associated with traditional SRAMs. In
addition, these technologies can reduce operating power consumption by
a factor of four compared with traditional SRAM technology,
contributing to making them ideal for embedding large memories in
System on Chip (SoC) designs. MoSys’ licensees have shipped more than
50 million chips incorporating 1T-SRAM embedded memory technologies,
demonstrating excellent manufacturability in a wide range of silicon
processes and applications. MoSys is headquartered at 1020 Stewart
Drive, Sunnyvale, California 94085. More information is available on
MoSys’ website at http://www.mosys.com.

About Accelerant Networks

Accelerant Networks is a fabless semiconductor company delivering
intelligent silicon transceivers that unlock new levels of bandwidth
from low-cost interconnects such as backplanes and cables used
commonly in the network, storage, and server markets. The company is
headquartered in Beaverton, Ore., with sales and application offices
in Silicon Valley, as well as a nationwide network of sales
representatives. For more information visit Accelerant on the web at
www.Accelerant.net.

Additional Information and Where to Find It

This release is being filed pursuant to Rule 425 under the
Securities Act of 1933. This announcement is neither an offer to
purchase nor a solicitation of an offer to sell shares of Monolithic
System Technology, Inc. (MoSys). MoSys stockholders are urged to read
the relevant exchange offer documents when they become available
because they will contain important information that stockholders
should consider before making any decision regarding tendering their
shares. At the time the offer, if any, is commenced, Synopsys will
file exchange offer materials with the U.S. Securities and Exchange
Commission and MoSys will file a Solicitation/Recommendation Statement
with respect to the offer. The exchange offer materials (including a
Preliminary Prospectus/Offer to Purchase, a related Letter of
Transmittal and certain other offer documents) and the
Solicitation/Recommendation Statement will contain important
information, which should be read carefully before any decision is
made with respect to the offer. The Preliminary Prospectus/Offer to
Purchase, the related Letter of Transmittal and certain other offer
documents, as well as the Solicitation/Recommendation Statement, will
be made available to all stockholders of MoSys at no expense to them.
The exchange offer materials (including a Preliminary Prospectus/Offer
to Purchase, a related Letter of Transmittal and certain other offer
documents) and the Solicitation/Recommendation Statement will be made
available for free at the Commission’s Web Site at www.sec.gov. Free
copies of the Preliminary Prospectus/Offer to Purchase, the related
Letter of Transmittal and certain other offering documents will be
made available by Synopsys for free at Synopsys’ website at
http://www.synopsys.com/corporate/invest/invest.html or by mail to
Synopsys, 700 Middlefield Road, Mountain View, CA 94043, attention:
Investor Relations.

In addition to the Preliminary Prospectus/Offer to Purchase, the
related Letter of Transmittal and certain other offer documents, as
well as the Solicitation/Recommendation Statement, Synopsys and MoSys
file annual, quarterly and special reports, proxy statements and other
information with the Securities and Exchange Commission. You may read
and copy any reports, statements or other information filed by
Synopsys or MoSys at the SEC public reference room at 450 Fifth
Street, N.W., Washington, D.C. 20549. Please call the Commission at
1-800-SEC-0330 for further information on the public reference room.
Synopsys’ and MoSys’ filings with the Commission are also available to
the public from commercial document-retrieval services and at the
website maintained by the Commission at http://www.sec.gov.

Interests of Certain Persons in the Merger.

Synopsys will be, and certain other persons may be, soliciting
MoSys stockholders to tender their shares into the offer. The
directors and executive officers of Synopsys and the directors and
executive officers of MoSys may be deemed to be participants in
Synopsys’ solicitation of MoSys’ stockholders to tender their shares
into the offer.

Synopsys is a registered trademark of Synopsys, Inc. All other
trademarks mentioned in this release are the intellectual property of
their respective owners.

CONTACT:
Synopsys, Inc.
Yvette Huygen, 650-584-4547
yvetteh@synopsys.com
or
Edelman Public Relations
Sarah Seifert, 650-429-2776
sarah.seifert@edelman.com
or
MoSys
Mark-Eric Jones, 408-731-1816
mejones@mosys.com
or
Accelerant Networks
Bill Hoppin, 415-383-3981
bhoppin@accelerant.net
or
Investor Contacts:
Synopsys, Inc.
Jessica Kourakos, 650-584-4289
jessicak@synopsys.com
or
MoSys
Mark Voll, 408-731-1846
markv@mosys.com

SOURCE: Monolithic System Technology, Inc.