EXHIBIT 5

 
                       CERTIFICATE OF AMENDMENT OF BYLAWS

                                       OF

                         QUICKTURN DESIGN SYSTEMS, INC.


     The undersigned hereby certifies that he is the duly elected and acting
Secretary of Quickturn Design Systems, Inc. and that the following amendments to
the corporation's Bylaws were approved by the corporation's Board of Directors
effective as of August 21, 1998:

1.   Section 2.3 of Article II of the Bylaws of this corporation is hereby
amended to read in its entirety as follows:

     "A special meeting of the stockholders may be called at any time by (i) the
     board of directors, (ii) the chairman of the board, (iii) the president,
     (iv) the chief executive officer or (v) subject to the procedures set forth
     in this Section 2.3, one or more stockholders holding shares in the
     aggregate entitled to cast not less than ten percent (10%) of the votes at
     that meeting.

     Upon request in writing sent by registered mail to the president or chief
     executive officer by any stockholder or stockholders entitled to call a
     special meeting of stockholders pursuant to this Section 2.3, the board of
     directors shall determine a place and time for such meeting, which time
     shall be not less than ninety (90) nor more than one hundred (100) days
     after the receipt and determination of the validity of such request, and a
     record date for the determination of stockholders entitled to vote at such
     meeting in the manner set forth in Section 2.12 hereof. Following such
     receipt and determination, it shall be the duty of the secretary to cause
     notice to be given to the stockholders entitled to vote at such meeting, in
     the manner set forth in Section 2.4 hereof, that a meeting will be held at
     the place and time so determined."

     IN WITNESS WHEREOF, the undersigned has executed this Certificate as of the
date first written above.

                                         /s/ Raymond K. Ostby
                                         -------------------------
                                         By:  Raymond K. Ostby
                                         Secretary