<PAGE>
                                                                   EXHIBIT 10.59



This offer given to Executive on August 29, 2001
                                    This offer is valid until September 19, 2001

             EXECUTIVE SEPARATION, RELEASE AND CONSULTING AGREEMENT

         This Executive Separation, Release and Consulting Agreement (the
"Agreement") is entered into between Robert P. Wiederhold (the "Executive"), on
the one hand, and Cadence Design Systems, Inc., a Delaware corporation
("Cadence") and Tality Corporation, a Delaware corporation ("Tality"), on the
other hand, (collectively, the "Company"), as of this ___ day of _________,
2001.

         WHEREAS, the Executive desires to resign his employment as President
and Chief Executive Officer of Tality; and

         WHEREAS, Cadence and Executive entered into that certain Tality
Corporation 2000 Equity Incentive Plan Stock Option Agreement with Consent dated
as of July 13, 2000 (the "Tality Option Agreement"); and

         WHEREAS, Cadence and Executive desire to amend the Tality Option
Agreement as more particularly set forth herein; and

         WHEREAS, the Executive and the Company desire to reach an agreement
concerning the circumstances under which the Executive's full-time employment
relationship with the Company will terminate; and

         WHEREAS, the Company desires to be relieved of any and all duties,
obligations, and/or liabilities, if any exist, with respect to Executive, other
than those obligations and duties which are expressly stated in herein;

         NOW THEREFORE, in consideration of the foregoing recitals, the mutual
promises contained herein, and for other good and valuable consideration, the



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receipt and adequacy of which are hereby acknowledged, the Executive and the
Company agree as follows:

1.       Full-Time Employment.

         Executive will cease his full-time employment as President and Chief
         Executive Officer of Tality on August 31, 2001, at the close of
         business.

2.       Part-Time Employment Period.

         a. From September 1, 2001 through September 1, 2002, Executive shall
         continue as a part-time employee of the Company for a one-year term
         (the "Part-Time Employment Period"). Employee's employment with the
         Company shall terminate at the end of the Part-Time Employment Period.
         Executive recognizes that he is committing to remain as a part-time
         employee with the Company through the end of the Part-Time Employment
         Period and he agrees not to voluntarily terminate his employment with
         the Company during the Part-Time Employment Period. Likewise, the
         Company may not terminate Executive's employment during such period
         except for cause. Cause shall exist if the Executive: (1) materially
         breaches this Agreement or the Employee Proprietary Information and
         Inventions Agreement, which is referenced in Section 11 hereof; (2)
         fails to perform his duties after receipt of written notice of such
         failure and a reasonable opportunity to cure; (3) commits any breach of
         fiduciary duty or act of theft, misappropriation, embezzlement,
         intentional fraud or other violation of the law or similar conduct
         involving the Company or any affiliate; (4) receives a conviction or
         enters a plea of Nolo Contendere or the equivalent in respect of a



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         felony involving an act of dishonesty, moral turpitude, deceit or
         fraud; or (5) willfully or negligently causes any damage of a material
         nature to the business or property of the Company or any affiliate. If
         the Company terminates Executive without cause during the Part-Time
         Employment Period, or his employment terminates as a result of
         Executive's death or permanent disability, he (or his estate) shall
         continue to receive the same pay and benefits as if though his
         employment had continued through the end of the Part-Time Employment
         Period.

         b. During the Part-Time Employment Period, Executive shall be available
         to consult to the Company, and/or the Board of Directors of Tality or
         Cadence as necessary. During the Part-Time Employment Period, Executive
         shall report to Ray Bingham (or his successor(s)) and shall, in
         addition to providing general advice and consultation to the Company
         and its Board(s), perform other duties, including but not limited to,
         facilitating the transfer of customer relationships to members of the
         management team, participating in creating strategic direction for
         Tality, assist with litigation, claims, customer and/or supplier issues
         when requested by the Board or management of the Company to do so, and
         participate as a member of the Tality Board. Executive's performance of
         his duties during this period shall not require him to work more than a
         maximum of twenty (20) hours per week.

         c. In consideration for such employment, Executive shall be paid a
         monthly salary of $29,166.66, less taxes and standard withholdings
         required by law to be withheld, and deductions requested by Executive.


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<PAGE>

         Such compensation will be paid in accordance with the Company's normal
         payroll schedule.

         d. So long as Executive remains a part-time employee of the Company
         through September 1, 2002 and does not in any way breach this
         Agreement, Executive shall receive a bonus in the amount of $167,000,
         less taxes and withholdings required by law to be withheld, and
         deductions requested by Executive, on or about September 1, 2002.

         e. Executive shall continue to receive medical, dental and/or vision
         insurance coverage which the Executive elected and which the Executive
         continues to pay for under the Cadence Composition plan through the end
         of the Part-Time Employment Period, or until he secures such benefits
         through other means, after which time the Executive will become
         eligible to continue such coverage pursuant to the terms of COBRA at
         prevailing rates. All other employee benefits, including but not
         limited to the Employee Stock Purchase Plan, 401(k) contribution, life,
         dependent life and disability insurance and Midwest Legal Services
         likewise will terminate at the end of the Part-Time Employment Period.
         Executive's funds invested in the Company's Non Qualified Deferred
         Compensation Plan (the "Plan"), if any shall be treated in accordance
         with the terms of the Plan.

         f. Executive's Company stock options that were previously granted to
         Executive shall continue to vest during the Part-Time Employment Period
         in accordance with the Stock Option Plan(s) and Stock Option
         Agreement(s) under which the options were granted, so long as Executive



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<PAGE>

         has executed all necessary stock option agreements on or before August
         31, 2001. Those options will cease vesting at the end of the Part-Time
         Employment Period, and Executive will have the period of time following
         his Termination Date that is provided in the applicable stock option
         agreement(s) to exercise the vested portions, if any.

         g. No Acceleration of Tality Options on Change in Control. Executive
         hereby acknowledges and agrees that Section 11 (b) of the "Plan" (as
         that term is defined in the Tality Option Agreement) shall not apply to
         the options granted to Executive under the Tality Option Agreement (the
         "Tality Options"). For the avoidance of doubt, but without limiting the
         generality of the foregoing, Executive hereby acknowledges and agrees
         that the Tality Options shall not vest or accelerate upon a "Change in
         Control" (as that term is defined in the Plan).

         h. Executive will be free to accept other employment or consulting
         engagements during the Part-Time Employment Period, so long as such
         other employment or consulting engagement does not violate paragraph 12
         herein.

3.       2001 Bonus

         Executive shall receive a bonus in the amount of $250,000, less taxes
         and withholdings required by law to be withheld, and amounts requested
         by him to be deducted, on or about February 15, 2002, so long as
         Executive continues in his part-time employment capacity with the
         Company through that date and has not in any way breached this
         Agreement.

4.       Computer



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         Executive shall be given all right, title and interest in the IBM
         Thinkpad, monitor, docking station, keyboard and mouse which was
         provided to him for business use by the Company during the year
         2000.Executive agrees, however, to delete all proprietary and
         confidential information belonging to the Company from the computer
         when requested to do so, and agrees to allow a representative of the
         Company to review the files on the computer upon request to ensure that
         all such information has been deleted.

5.       Business Expense

         Executive shall be reimbursed for all reasonable and necessary business
         expenses incurred during his full and part-time employment with the
         Company. Such expenses must be approved by Ray Bingham, or an
         individual designated by Mr. Bingham to approve such expenses, and must
         be submitted for reimbursement with appropriate documentation not more
         than ninety (90) days following the date on which the expense was
         incurred, and prior to the termination of his employment with the
         Company.

6.       DSL

         The Company will continue to pay for the Executive's DSL line at his
         residence through the end of the Part-Time Employment Period, at which
         time such payments on behalf of Executive shall cease.

7.       Executive acknowledges and agrees that he is not entitled to any of the
         benefits provided in that Tality Corporation Employment Agreement
         between he and Tality that was entered into on July 14, 2000, and that
         this Agreement supercedes the Tality Corporation Employment Agreement.



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<PAGE>

8.       During the Part-Time Employment Period, and following his termination
         of employment, Executive shall fully cooperate with the Company in all
         matters relating to his employment, the winding up of his pending work
         on behalf of the Company and the orderly transfer of any such pending
         work to other employees of the Company as may be designated by the
         Company.

9.       The Executive agrees not to make any statement, written or oral, or
         otherwise engage in any communication which disparages the Company or
         any of the Company's employees, directors, or representatives,
         products, or business practices.

10.      General Release by Executive

                  (a) The Executive agrees that the payments and benefits
         provided herein are in full satisfaction of all obligations of the
         Company to the Executive arising out of or in connection with the
         Executive's employment including, without limitation, all salary,
         bonuses, accrued vacation, sick pay, and two weeks salary as standard
         termination notice period, and that the benefit of continued stock
         vesting constitutes consideration for the covenants and releases of the
         Executive as set forth herein. The Executive acknowledges that the
         Executive has no claims against the Company based on the Executive's
         employment by the Company or the Executive's separation therefrom and
         irrevocably, fully and finally releases the Company, its parent,
         subsidiaries and affiliates, and its current and former directors,
         officers, agents, attorneys, and employees ("Releasees") from all
         causes of action, claims, suits, demands or other obligations or
         liabilities, whether known or unknown, that Executive ever



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         had, or now has, including but not limited to, any claims that may be
         alleged to arise out of or in connection with the Executive's
         employment with the Company, or separation therefrom, including, not by
         way of limitation, any claims for wages, bonuses, and any claims that
         any terms of the Executive's employment with the Company or any
         circumstances of the Executive's separation were wrongful, in breach of
         any obligation of the Company or in violation of any rights,
         contractual, statutory or otherwise, of the Executive, including but
         not limited to rights arising under Title VII of the Civil Rights Act
         of 1964, as amended, the California Fair Employment and Housing Act, as
         amended, the California Labor Code, the Age Discrimination in
         Employment Act of 1967, as amended, the Americans with Disabilities
         Act, the Equal Pay Act, the Fair Labor Standards Act, as amended, the
         Executive Retirement Income and Security Act of 1974, as amended,
         (except for Executive's rights under COBRA and Executive's rights to
         the money in Executive's 401(k) plan account and deferred compensation
         plan account(s)), and any other local, state, or federal law, or law of
         any country, governing discrimination in employment, the payment of
         wages or benefits, or any other aspect of employment (collectively,
         "Claims").

          IN THIS REGARD THE EXECUTIVE WAIVES ANY RIGHTS CONFERRED BY CALIFORNIA
         CIVIL CODE SECTION 1542 WHICH PROVIDES AS FOLLOWS:

         "A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES
         NOT KNOW OR SUSPECT TO EXIST IN HIS FAVOR WHICH IF KNOWN BY HIM MUST
         HAVE MATERIALLY AFFECTED HIS SETTLEMENT WITH THE DEBTOR."



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<PAGE>

                  (b) The release set forth in section (a) above does not and
         shall not extend to any obligations of the Company incurred under this
         Agreement or under the Indemnification Agreement which was signed by
         Executive on or about July 14, 2001 and is attached hereto as Exhibit
         A.

                  (c) The Executive acknowledges that he understands that he may
         take twenty-one (21) days to consider this Agreement and that he has
         been advised that he should consult with an attorney, if he desires to
         do so, prior to executing this Agreement. The Executive further
         acknowledges that he understands that he may revoke this Agreement
         within seven (7) days of his execution of this document and that the
         consideration to be paid to the Executive pursuant to this Agreement
         will be paid only after that seven (7) day revocation period.

11.      Executive acknowledges and incorporates herein by reference his
         continuing obligations under the Employee Proprietary Information and
         Inventions Agreement executed by Executive on July 14, 2000, a copy of
         which is attached hereto as Exhibit B.

12.      As President and CEO of Tality and as a Senior Executive and Officer of
         Cadence, Executive has obtained extensive and valuable knowledge and
         information concerning the business of the Company (including
         confidential information relating to the Company and its operations,
         assets, contracts, customers, personnel, plans, marketing plans,
         research and development plans and prospects). The Executive and the
         Company agree that it would be virtually impossible for Executive to
         work as an employee, consultant or advisor to a company in the
         electronic design automation



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         industry without inevitably disclosing confidential and proprietary
         information belonging to the Company. Accordingly, the Executive agrees
         that, during the Part-Time Employment Period he will not, directly or
         indirectly, provide services on behalf of any competing corporation,
         limited liability company, partnership, or other competing entity or
         person, specifically including but not limited to Avant! Corporation,
         Synopsys Inc., Mentor Graphics Corporation, Simplex Solutions, Inc.,
         Magma Design Automation, Inc., or any subsidiary, affiliate, division,
         distributor or partial or complete successor thereof, whether as an
         employee, consultant, independent contractor, agent, sole proprietor,
         partner, joint venture, corporate officer or director; nor shall
         Executive acquire by reason of purchase during the term of his
         employment with the Company the ownership of more than one percent (1%)
         of the outstanding equity interest in any such competing entity. For
         purposes of this Section 12, a "competing" entity is one that is
         engaged in the research, design, development, marketing and/or sale of
         electronic design automation software and related products, including
         products containing hardware, software and both hardware and/or
         software. For purposes of this Section 12 a "competing" entity is also
         one that derives a substantial portion of its business from design
         services and/or intellectual property sales and/or licensing relating
         to semiconductors, systems and/or design methodologies.

13.      During the Term of Executive's employment with the Company, Executive
         agrees that he will not, except with the written advance approval of
         Ray Bingham (or his successor(s)), voluntarily or



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         involuntarily, for any reason whatsoever, directly or indirectly,
         individually or on behalf of persons not now parties to this Agreement,
         or as a partner, stockholder, director, officer, principal, agent,
         employee or in any other capacity or relationship, for his own account
         or for the benefit of any other person or entity: (a) encourage,
         induce, attempt to induce, solicit or attempt to solicit anyone who is
         employed at that time, or was employed during the previous one (1)
         year, by the Company or any affiliate to leave his or her employment
         with the Company or any affiliate; or (b) interfere or attempt to
         interfere with the relationship or prospective relationship of the
         Company or any affiliate with any former, present or future client,
         customer, joint venture partner, or financial backer of the Company or
         any affiliate; or (c) solicit, divert or accept business, in any line
         or area of business engaged in by the Company or any affiliate, from
         any former, present or future client, customer or joint venture partner
         of the Company or any affiliate (other than on behalf of the Company).
         This paragraph shall supercede paragraph five (5) of the Employee
         Proprietary Information and Inventions Agreement executed by Executive
         on July 14, 2000, a copy of which is attached hereto as Exhibit B.

14.      During the six (6) months following Executive's employment with the
         Company, Executive agrees that he will not, except with the advance
         written approval of the the Chairman of the Board of Tality,
         voluntarily or involuntarily, for any reason whatsoever,



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         directly or indirectly, individually or on behalf of persons not now
         parties to this Agreement, or as a partner, stockholder, director,
         officer, principal, agent, employee or in any other capacity or
         relationship, for his own account or for the benefit of any other
         person or entity: (a) encourage, induce, attempt to induce, solicit or
         attempt to solicit anyone who is employed at that time, or was employed
         during the previous one (1) year, by Tality or any affiliate to leave
         his or her employment with Tality or any affiliate; or (b) interfere or
         attempt to interfere with the relationship or prospective relationship
         of Tality or any affiliate with any former, present or future client,
         customer, joint venture partner, or financial backer of Tality or any
         affiliate; or (c) solicit, divert or accept business, in any line or
         area of business engaged in by Tality or any affiliate, from any
         former, present or future client, customer or joint venture partner of
         Tality or any affiliate. This paragraph shall supercede paragraph five
         (5) of the Employee Proprietary Information and Inventions Agreement
         executed by Executive on July 14, 2000, a copy of which is attached
         hereto as Exhibit B.

15.      Notwithstanding the language in paragraph 24 herein, the parties hereto
         agree that damages would be an inadequate remedy for the Company in the
         event of a breach or threatened breach of Section 8, 11, 12, 13, 14 or
         19 of this Agreement by Executive, and in the event of any such breach
         or threatened breach, the Company may, either with or without pursuing
         any potential damage remedies, obtain and enforce an injunction
         prohibiting Executive from violating this



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         Agreement and requiring Executive to comply with the terms of this
         Agreement.16.Executive represents and acknowledges that the Executive's
         decision to enter into this Agreement has been made voluntarily,
         knowingly, and without coercion of any kind.

17.      Executive represents and warrants that there has been no assignment or
         other transfer of any interest in any Claim, which Executive may have
         against the Releasees.

18.      Executive agrees that if the Executive hereafter commences, joins in,
         or in any manner seeks relief through any suit, claim, demand, charge,
         complaint or otherwise, arising out of, based upon, or relating to any
         of the Claims released hereunder or in any manner asserts against the
         Releasees any of the Claims released hereunder, then the Executive will
         pay to the Releasees, in addition to any other damages caused thereby,
         all reasonable attorneys' fees incurred by the Releasees in defending
         or otherwise responding to said suit or Claim.

19.      Executive acknowledges that during his employment he has had access to
         confidential and/or proprietary information of the Company and of third
         parties and acknowledges the Executive's obligation by agreement and/or
         at common law to continue to hold such information in confidence and
         neither disclose and/or use such information, notwithstanding the
         termination of his employment, and that he has returned to the Company
         all copies and records in any form of such information to Ron
         Kirchenbauer, or will do so prior to his termination date. Executive
         further agrees to return all other property (including but not limited
         to computers, phones,



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         fax machines, and printers) to Ron Kirchenbauer by September 1, 2001,
         except for as provided for in paragraph 4.

20.      This Agreement shall be governed and enforced in accordance with the
         laws of the State of California, excluding its conflict of laws rules.


21.      In the event that any part of this Agreement is found to be void or
         unenforceable then (a) such provision or part thereof shall, with
         respect to such circumstances and in such jurisdiction, be deemed
         amended to conform to applicable laws so as to be valid and enforceable
         to the fullest possible extent, (b) the invalidity or unenforceability
         of such provision or part thereof under such circumstances and in such
         jurisdiction shall not affect the validity or enforceability of such
         provision or part thereof under any other circumstances or in any other
         jurisdiction, and (c) such invalidity or enforceability of such
         provision or part thereof shall not affect the validity or
         enforceability of the remainder of such provision or the validity or
         enforceability of any other provision of this Agreement as each
         provision is separable from every other provision. If for any reason a
         court of competent jurisdiction or arbitrator finds any provision of
         this Agreement to be unenforceable, the provision shall be deemed
         amended as necessary to conform to applicable laws or regulations, or
         if it cannot be so amended without materially altering the intention of
         the parties, the remainder of the Agreement shall continue in full
         force and effect as if the offending provision were not contained
         herein.

22.      Neither party shall, by mere lapse of time, without giving notice or
         taking other action hereunder be deemed to have waived any breach by
         the other



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         party of any of the provisions of this Agreement. Further, the waiver
         by either party of a particular breach of this Agreement by the other
         shall neither be construed as, nor constitute, a continuing waiver of
         such breach or of other breaches by the same or any other provision of
         this Agreement.

23.      The Company shall have the right to assign its rights and obligations
         under this Agreement to an entity that acquires substantially all of
         the assets of the Company. The rights and obligations of the Company
         under this Agreement shall inure to the benefit and shall be binding
         upon the successors and assigns of the Company. Executive shall not
         have any right to assign his obligations under this Agreement and shall
         only be entitled to assign his rights under this Agreement by will or
         the laws of descent and distribution.

24.      The Company and Executive agree that any dispute regarding the
         interpretation or enforcement of this Agreement or any dispute arising
         out of Executive's employment or the termination of that employment
         with the Company, except for disputes regarding the interpretation of
         those sections referred to in Paragraph 14 and disputes involving the
         protection of the Company's intellectual property, shall be decided by
         confidential, final and binding arbitration conducted by Judicial
         Arbitration and Mediation Services ("JAMS") under the then-existing
         JAMS rules, rather than by litigation in court, trial by jury,
         administrative proceeding, or in any other forum.

25.      The parties hereto acknowledge that each has read this Agreement,
         understands it, and agrees to be bound by its terms. The parties
         further agree that this Agreement, including the agreements referenced
         herein and attached as Exhibits hereto, constitute the complete and
         exclusive statement



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         of the agreement between the parties and supersede any and all prior or
         contemporaneous understandings, agreements, representations,
         conditions, covenants, proposals, and all other communications between
         the parties, whether written or oral, relating to the subject matter
         hereof.

26.      This Agreement and the terms and conditions of the matters addressed in
         this Agreement may only be amended in writing executed both by the
         Executive and a duly authorized representative of the Company.

In witness whereof, the parties hereto have executed this Executive Termination
and Release Agreement, effective eight (8) days after the date it is signed by
both parties below (the "Effective Date").

ROBERT P. WIEDERHOLD                   CADENCE DESIGN SYSTEMS, INC.


By:                                    By:
   ---------------------------            ------------------------------------
                                          H. Raymond Bingham
Date:                                     President & Chief Executive
     -------------------------            Officer

                                        Date:
                                             ---------------------------------


                                                      TALITY CORPORATION

                                        Date:
                                             ---------------------------------
                                              H. Raymond Bingham
                                              Chairman of the Board


                                        Date:
                                             ---------------------------------



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