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                                                                     EXHIBIT 3.1

                AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                               ALTERA CORPORATION


                   (ORIGINALLY INCORPORATED ON MARCH 25, 1997)

        FIRST. The name of the corporation is Altera Corporation.

        SECOND. The address of the corporation's registered office in the State
of Delaware is One Rodney Square, 10th Floor, Tenth and King Streets, in the
City of Wilmington, County of New Castle, 19801. The name of its registered
agent at such address is RL&F Service Corp.

        THIRD. The purpose of the corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of the State of Delaware.

        FOURTH. The total number of shares of stock which the corporation shall
have authority to issue is one billion (1,000,000,000). All such shares are to
be Common Stock, par value of $0.001 per share, and are to be of one class.

        FIFTH. Unless and except to the extent that the by-laws of the
corporation shall so require, the election of directors of the corporation need
not be by written ballot.

        SIXTH. In furtherance and not in limitation of the powers conferred by
the laws of the State of Delaware, the Board of Directors of the corporation is
expressly authorized to adopt, alter, amend and repeal the by-laws of the
corporation, subject to the power of the stockholders of the corporation to
alter or repeal any by-law whether adopted by them or otherwise.

        SEVENTH. A director of the corporation shall not be liable to the
corporation or its stockholders for monetary damages for breach of fiduciary
duty as a director, except to the extent such exemption from liability or
limitation thereof is not permitted under the General Corporation Law of the
State of Delaware as the same exists or may hereafter be amended. Any amendment,
modification or repeal of the foregoing sentence shall not adversely affect any
right or protection of a director of the corporation hereunder in respect of any
act or omission occurring prior to the time of such amendment, modification or
repeal.

        EIGHTH. No action that is required or permitted to be taken by the
stockholders of the Corporation at any annual or special meeting of stockholders
may be effected by written consent of stockholders in lieu of a meeting of
stockholders. Notwithstanding anything contained in this Amended and Restated
Certificate of Incorporation to the contrary, the affirmative vote of at least
eighty percent (80%) in voting power of the then outstanding voting stock of the
corporation, voting together as a single class, shall be required to amend,
repeal or adopt any provision inconsistent with the Article Eighth.



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        NINTH. The corporation reserves the right at any time, and from time to
time, to amend, alter, change or repeal any provision contained in this Amended
and Restated Certificate of Incorporation, and other provisions authorized by
the laws of the State of Delaware at the time in force may be added or inserted,
in the manner now or hereafter prescribed by law; and all rights, preferences
and privileges or whatsoever nature conferred upon stockholders, directors or
any other persons whomsoever by and pursuant to this Amended and Restated
Certificate of Incorporation in its present form or as hereafter amended are
granted subject to the rights reserved in this article.

        Altera Corporation, a Delaware corporation, hereby certifies that the
foregoing Amended and Restated Certificate of Incorporation, which restates,
integrates and further amends the provisions of the Certificate of Incorporation
of this corporation as heretofore amended or supplemented, has been duly adopted
by the corporation's Board of Directors and stockholders in accordance with
Sections 242 and 245 of the Delaware General Corporation Law, with the approval
of the corporation's stockholders having been given at the annual meeting of
stockholders.

        IN WITNESS WHEREOF, said corporation has caused this Amended and
Restated Certificate of Incorporation to be signed by its duly authorized
officer on this 2nd day of May, 2001 and the foregoing facts stated herein are
true and correct.


                                       ALTERA CORPORATION



                                       By: /s/ JOHN P. DAANE
                                           -------------------------------------
                                       John P. Daane
                                       President and Chief Executive Officer



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