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                        Quickturn Design Systems, Inc.
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                                                                   EXHIBIT 99.57

FOR IMMEDIATE RELEASE


                     CADENCE AND QUICKTURN AGREE TO MERGE
              Stock-for-Stock Transaction Valued at $253 Million;
               Value of $14 per share to Quickturn Shareholders

     SAN JOSE, Calif. -- December 9, 1998 -- Cadence Design Systems, Inc.
(NYSE:CDN) and Quickturn Design Systems, Inc. (NASDAQ:QKTN) today announced that
the boards of directors of both companies unanimously approved a definitive
merger agreement under which Cadence will acquire Quickturn in a tax-free,
stock-for-stock transaction with an aggregate purchase price of $253 million.
Upon closing of the merger, each shareholder of Quickturn will receive Cadence
common stock with a value of $14 per share.

     Quickturn is a leading provider of emulation systems and time-to-market
engineering (TtME(TM)) services for the verification of complex integrated
circuits (ICs) and electronic systems.  Cadence is a world leader in electronic
design software and services.

     Jack Harding, President and CEO of Cadence, said:  "We are presenting
Quickturn's shareholders with an extraordinary opportunity to participate in the
increased growth and earnings potential that this very compelling business
combination will deliver.

     "As the complexity of chip design increases, the complexity of verification
increases exponentially.  By integrating Quickturn's hardware-based emulation
approach with our software design and simulation systems, we will dramatically
improve our ability to meet customer demand for faster development of high-speed
systems on a chip.  We believe this merger will be seen as an important
milestone in the development of next generation verification solutions," Harding
said.

     "The combination of Cadence and Quickturn meets our objectives for growing
our business through acquisitions of complementary businesses that have
management depth and engineering talent," Harding added.

     Keith R. Lobo, President and CEO of Quickturn, said: "A merger with Cadence
is a superior outcome for our shareholders, our employees, and our customers,
and allows Quickturn to continue to pursue its business strategy. Cadence has a
proven business

                                   -- more --

 
strategy, a strong balance sheet and an excellent track record in acquiring and
integrating companies. We believe our shareholders will recognize the value of
this combination, which yields both short-term benefits and tremendous potential
upside in the long term. We look forward to leveraging Cadence's strong
international sales channels to make our technology available to a larger
customer base."
 
TERMS OF THE MERGER AGREEMENT

     Cadence said the merger would be accounted for as a pooling of interests
and that it expects the transaction to be accretive to earnings in 1999.  As a
result of the merger, Quickturn will become a wholly-owned subsidiary of
Cadence.

     Quickturn has issued Cadence an option to purchase 19.9% of the outstanding
common stock of Quickturn for $14 a share, which will become exercisable under
certain conditions.

     The merger is subject to certain conditions, including compliance with
applicable regulatory requirements, and approval by Quickturn's shareholders.
It is expected to close in the first quarter of 1999.

     Goldman, Sachs & Co. acted as financial advisor to Cadence. Hambrecht &
Quist LLC acted as financial advisor to Quickturn.

ABOUT CADENCE

     Cadence Design Systems, Inc. provides comprehensive services and software
for the product development requirements of the world's leading electronics
companies.  Cadence is the largest supplier of software products, consulting
services, and design services used to accelerate and manage the design of
semiconductors, computer systems, networking and telecommunications equipment,
consumer electronics, and a variety of other electronic-based products.  With
more than 4,000 employees and 1997 annual sales of $916 million, Cadence has
sales offices, design centers, and research facilities around the world.  The
company is headquartered in San Jose, Calif. and traded on the New York Stock
Exchange under the symbol CDN.  More information about the company, its products
and services may be obtained from the World Wide Web at http://www.cadence.com.
                                                        ---------------------- 

                                   -- more --

 
ABOUT QUICKTURN

     Quickturn Design Systems, Inc. is a leading provider of verification
hardware and time-to-market engineering (TtMETM) services for the design of
complex ICs and electronic systems.  The company's products are used worldwide
by developers of high-performance computing, multimedia, graphics and
communications systems.  Quickturn is headquartered in San Jose, Calif.  For
more information, visit the Quickturn Web site at http://www.quickturn.com or
                                                  ------------------------   
send e-mail to info@quickturn.com.

     This release contains forward-looking statements based on current
expectations or beliefs as well as a number of assumptions about future events,
and that are subject to factors and uncertainties that could cause actual
results to differ materially from those described in the forward-looking
statements.  The reader is cautioned not to put undue reliance on these forward-
looking statements, which are not a guarantee of future performance and are
subject to a number of uncertainties and other factors, many of which are
outside the control of Cadence and Quickturn.  The forward-looking statements in
this release address a variety of subjects including, for example, the expected
date of closing of the acquisition, the transaction being accretive to earnings
in 1999, and the potential benefits of the merger.  The following factors, among
others, could cause actual results to differ materially from those described in
these forward-looking statements: the risk that Quickturn's business will not be
successfully integrated with Cadence's business; costs associated with the
merger; the inability to obtain the approval of Quickturn's shareholders;
matters arising in connection with the parties' efforts to comply with
applicable regulatory requirements relating to the transaction; and increased
competition and technological changes in the industry in which Cadence and
Quickturn compete.  For a detailed discussion of these and other cautionary
statements, please refer to Cadence's and Quickturn's filings with the
Securities and Exchange Commission, including their respective Annual Reports on
Form 10-K for the year ended December 31, 1998 and their respective Quarterly
Reports on Form 10-Q for the quarter ended September 30, 1998.
                                   -- end --

Cadence and the Cadence logo are registered trademarks of Cadence Design
Systems, Inc. All other brands or product names are the property of their
respective holders.

FOR CADENCE DESIGN SYSTEMS, INC.
Media Contact                   Investor Contact
- -------------                   ----------------
Laurie Stanley                  Ray Bingham
Cadence Design Systems, Inc.    Cadence Design Systems, Inc.
(408) 428-5019                  (408) 944-7503

or

Robert Mead
Gavin Anderson & Co.
(212) 373-0226

FOR QUICKTURN DESIGN SYSTEMS, INC.
Ray Ostby
Quickturn Design Systems, Inc.
(408) 914-6000

or

Pauline Yoshihashi              Matt Sherman
Abernathy MacGregor Frank       Abernathy MacGregor Frank
(213) 630-6550                  (212) 371-5999