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                                                                     EXHIBIT 4.2



                   FIRST AMENDED AND RESTATED RIGHTS AGREEMENT


        THIS FIRST AMENDED AND RESTATED RIGHTS AGREEMENT (the "Agreement") is
entered into as of the 4th day of August, 2000, by and among PDF Solutions,
Inc., a California corporation (the "Company"), the holders of shares of Series
A Preferred Stock (the "Series A Purchasers") and Series B Preferred Stock (the
"Series B Purchasers") listed on Exhibit A hereto, (the Series A Purchasers and
Series B Purchasers are referred to herein collectively as the "Preferred
Purchasers," and certain other shareholders listed on Exhibit B hereto (the
"Founders" and collectively with the Series A Purchasers and Series B Purchasers
the "Purchasers" or the "Investors").


                                    RECITALS

        WHEREAS, the Company, the Series A Purchasers and the Founders have
entered into a Rights Agreement dated as of December 4, 1995 (the "Original
Rights Agreement"). The Company, the Founders, and a majority of the holders of
Series A Preferred Stock desire to amend and restate in its entirety the
Original Rights Agreement in accordance with Section 3.7 thereof.

        WHEREAS, the Company and the Series B Purchasers are entering into a
Series B Preferred Stock Purchase Agreement of even date herewith (the "Purchase
Agreement"), pursuant to which the Company shall sell, and the Series B
Purchasers shall acquire, shares of the Company's Series B Preferred Stock.

        WHEREAS, a condition to the Series B Purchasers' obligations under the
Purchase Agreement is that the Company and the Purchasers enter into this
Agreement in order to provide the Series B Purchasers with (i) certain rights to
register shares of the Company's Common Stock issuable upon conversion of the
Series B Preferred Stock held by the Series B Purchasers and (ii) a right of
participation with respect to certain issuances by the Company of its
securities. The Company desires to induce the Series B Purchasers to purchase
shares of Series B Preferred Stock pursuant to the Purchase Agreement by
agreeing to the terms and conditions set forth herein.

        NOW, THEREFORE, IN CONSIDERATION OF THE MUTUAL PROMISES AND COVENANTS
HEREINAFTER SET FORTH, THE PARTIES AGREE that effective and contingent upon
execution of this Agreement by the Company and the holders of a majority of the
Registrable Securities, as that term is defined in the Original Rights
Agreement, not including the stock held by the Founders, and upon closing of the
transactions contemplated by the Purchase Agreement, the Original Rights
Agreement is hereby amended and restated in its entirety to read as set forth in
this Agreement, and the Company, the Founders, and the Investors hereby agree to
be bound by the provisions hereof as the sole agreement of the Company, the
Founders and the Investors with respect to registration rights of the Company's
securities and certain other rights, as set forth herein;

         AND FURTHER AGREE AS FOLLOWS:



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                                    SECTION 1

                        Restrictions on Transferability;
                               Registration Rights

        1.1 Certain Definitions. As used in this Agreement, the following terms
shall have the following respective meanings:

            "Commission" shall mean the Securities and Exchange Commission or
any other federal agency at the time administering the Securities Act.

            "Common Shares" shall mean all shares of Common Stock issued to the
Founders as of the date hereof.

            "Conversion Shares" shall mean the Common Stock issued or issuable
upon conversion of the Preferred Shares as defined herein.

            "Holder" shall mean any Investor holding Registrable Securities and
any person holding Registrable Securities to whom the rights under this
Agreement have been transferred in accordance with Section 1.14 hereof.

            "Initiating Holders" shall mean Holders in the aggregate of not less
than fifty percent (50%) of the Registrable Securities as defined for purposes
of that particular section.

            "Major Purchaser" shall mean any Investor (together with its
affiliates) holding more than 100,000 shares of Registrable Securities.

            "Preferred Shares" shall mean shares of the Series A Preferred and
Series B Preferred Stock outstanding as of the date hereof.

            The terms "register," "registered" and "registration" refer to a
registration effected by preparing and filing a registration statement in
compliance with the Securities Act, and the declaration or ordering of the
effectiveness of such registration statement.

            "Registration Expenses" shall mean all expenses incurred by the
Company in complying with Sections 1.5, 1.6 and 1.7 of this Agreement,
including, without limitation, all registration, qualification and filing fees,
printing expenses, escrow fees, fees and disbursements of counsel for the
Company, blue sky fees and expenses, and the expense of any special audits
incident to or required by any such registration (but excluding the compensation
of regular employees of the Company which shall be paid in any event by the
Company).

            "Registrable Securities" means (i) the Common Shares except that all
such Common Shares shall not be included in the definition of Registrable
Securities for the purposes of Section 1.5 and 1.7; (ii) the Conversion Shares;
and (iii) any Common Stock of the Company issued or issuable in respect of the
Common Shares, Preferred Shares or Conversion Shares or other securities issued
or issuable with respect to the Preferred Shares, Conversion Shares or Common
Shares upon any stock split, stock dividend, recapitalization, or similar event,
or any Common Stock otherwise issued or issuable with respect to the Common
Shares, Conversion




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Shares or Preferred Shares; provided, however, that shares of Common Stock or
other securities shall only be treated as Registrable Securities if and so long
as they have not been (A) sold to or through a broker or dealer or underwriter
in a public distribution or a public securities transaction, or (B) sold in a
transaction exempt from the registration and prospectus delivery requirements of
the Securities Act under Section 4(1) thereof so that all transfer restrictions
and restrictive legends with respect thereto are removed upon the consummation
of such sale.

            "Restricted Securities" shall mean the securities of the Company
required to bear the legend set forth in Section 1.3 of this Agreement.

            "Securities Act" shall mean the Securities Act of 1933, as amended,
or any similar federal statute and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

            "Selling Expenses" shall mean all underwriting discounts, selling
commissions and stock transfer taxes applicable to the securities registered by
the Holders and all fees and disbursements of counsel for the Holders (except as
provided by Section 1.9).

        1.2 Restrictions. The Preferred Shares, the Conversion Shares and the
Common Shares shall not be sold, assigned, transferred or pledged except upon
the conditions specified in this Agreement, which conditions are intended to
ensure compliance with the provisions of the Securities Act. The Investors will
cause any proposed purchaser, assignee, transferee or pledgee of the Preferred
Shares, the Conversion Shares or the Common Shares to agree to take and hold
such securities subject to the provisions and upon the conditions specified in
this Agreement.

        1.3 Restrictive Legend. Each certificate representing (i) the Preferred
Shares, (ii) the Conversion Shares, (iii) the Common Shares and (iv) any other
securities issued in respect of the securities referenced in clauses (i), (ii)
and (iii) upon any stock split, stock dividend, recapitalization, merger,
consolidation or similar event, shall (unless otherwise permitted by the
provisions of Section 1.4 below) be stamped or otherwise imprinted with legends
in the following form (in addition to any legend required under applicable state
securities laws):

        "THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED FOR
        INVESTMENT AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
        1933. SUCH SHARES MAY NOT BE SOLD, TRANSFERRED OR PLEDGED IN THE ABSENCE
        OF SUCH REGISTRATION OR UNLESS THE COMPANY RECEIVES AN OPINION OF
        COUNSEL (WHICH MAY BE COUNSEL FOR THE COMPANY) REASONABLY ACCEPTABLE TO
        IT STATING THAT SUCH SALE OR TRANSFER IS EXEMPT FROM THE REGISTRATION
        AND PROSPECTUS DELIVERY REQUIREMENTS OF SAID ACT."

        Each Investor and Holder consents to the Company making a notation on
its records and giving instructions to any transfer agent of the Restricted
Securities in order to implement the restrictions on transfer established in
this Section 1.

        1.4 Notice of Proposed Transfers. The holder of each certificate
representing Restricted Securities, by acceptance thereof, agrees to comply in
all respects with the provisions of this Section 1. Prior to any proposed sale,
assignment, transfer or pledge of any Restricted




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Securities, unless there is in effect a registration statement under the
Securities Act covering the proposed transfer, the holder thereof shall give
written notice to the Company of such holder's intention to effect such
transfer, sale, assignment or pledge. Each such notice shall describe the manner
and circumstances of the proposed transfer, sale, assignment or pledge in
sufficient detail, and shall be accompanied at such holder's expense by either
(i) an unqualified written opinion of legal counsel who shall, and whose legal
opinion shall be, reasonably satisfactory to the Company, addressed to the
Company, to the effect that the proposed transfer of the Restricted Securities
may be effected without registration under the Securities Act, or (ii) a "no
action" letter from the Commission to the effect that the transfer of such
securities without registration will not result in a recommendation by the staff
of the Commission that action be taken with respect thereto, whereupon the
holder of such Restricted Securities shall be entitled to transfer such
Restricted Securities in accordance with the terms of the notice delivered by
the holder to the Company. The Company will not require such a legal opinion or
"no action" letter (a) in any transaction in compliance with Rule 144, (b) in
any transaction in which an Investor which is a corporation distributes
Restricted Securities after six (6) months after the purchase thereof solely to
its majority-owned subsidiaries or affiliates for no consideration, or (c) in
any transaction in which an Investor which is a partnership distributes
Restricted Securities after six (6) months after the purchase thereof solely to
partners thereof for no consideration, provided that each transferee agrees in
writing to be subject to the terms of this Section 1.4. Each certificate
evidencing the Restricted Securities transferred as above provided shall bear,
except if such transfer is made pursuant to Rule 144, the appropriate
restrictive legend set forth in Section 1.3 above, except that such certificate
shall not bear such restrictive legend if, in the opinion of counsel for such
holder and the Company, such legend is not required in order to establish
compliance with any provisions of the Securities Act.

        1.5 Requested Registration.

            (a) Request for Registration. In case the Company shall receive from
Initiating Holders a written request that the Company effect any qualification,
compliance or registration the reasonably anticipated aggregate price to the
public of which net of underwriting discounts and commissions, would exceed
$7,500,000, the Company shall:

                (i) promptly give written notice of the proposed registration,
qualification or compliance to all other Holders; and

                (ii) as soon as practicable, use its best efforts to effect such
registration, qualification or compliance (including, without limitation, the
execution of an undertaking to file post-effective amendments, appropriate
qualification under applicable blue sky or other state securities laws and
appropriate compliance with applicable regulations issued under the Securities
Act and any other governmental requirements or regulations) as may be so
requested and as would permit or facilitate the sale and distribution of all or
such portion of such Registrable Securities as are specified in such request,
together with all or such portion of the Registrable Securities of any Holder or
Holders joining in such request as are specified in a written request received
by the Company within twenty (20) days after receipt of such written notice from
the Company; provided, however, that the Company shall not be obligated to take
any action to effect any such registration, qualification or compliance pursuant
to this Section 1.5:




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                     (1) In any particular jurisdiction in which the Company
would be required to execute a general consent to service of process in
effecting such registration, qualification or compliance unless the Company is
already subject to service in such jurisdiction and except as may be required by
the Securities Act;

                     (2) Prior to the earlier of (i) six (6) months following
the Company's initial public offering or (ii) July 31, 2003;

                     (3) During the period ending on the date three (3) months
immediately following the effective date of any registration statement
pertaining to securities of the Company (other than a registration of securities
in a Rule 145 transaction or with respect to an employee benefit plan);

                     (4) After the Company has effected two (2) such
registrations pursuant to this subparagraph 1.5(a), such registrations have been
declared or ordered effective and the securities offered pursuant to such
registrations have been sold; or

                     (5) If the Company shall furnish to such Holders a
certificate, signed by the President of the Company, stating that in the good
faith judgment of the Board of Directors it would be seriously detrimental to
the Company or its shareholders for a registration statement to be filed in the
near future, then the Company's obligation to use its best efforts to register,
qualify or comply under this Section 1.5 shall be deferred for a single period
not to exceed one hundred-twenty (120) days from the date of receipt of written
request from the Initiating Holders.

        Subject to the foregoing clauses (1) through (5), the Company shall file
a registration statement covering the Registrable Securities so requested to be
registered as soon as practicable after receipt of the request or requests of
the Initiating Holders.

            (b) Underwriting. In the event that a registration pursuant to
Section 1.5 is for a registered public offering involving an underwriting, the
Company shall so advise the Holders as part of the notice given pursuant to
Section 1.5(a)(i). The right of any Holder to registration pursuant to Section
1.5 shall be conditioned upon such Holder's participation in the underwriting
arrangements required by this Section 1.5 and the inclusion of such Holder's
Registrable Securities in the underwriting, to the extent requested, to the
extent provided in this Agreement.

        The Company shall (together with all Holders proposing to distribute
their securities through such underwriting) enter into an underwriting agreement
in customary form with the managing underwriter selected for such underwriting
by a majority in interest of the Initiating Holders (which managing underwriter
shall be reasonably acceptable to the Company). Notwithstanding any other
provision of this Section 1.5, if the managing underwriter advises the
Initiating Holders in writing that marketing factors require a limitation of the
number of shares to be underwritten, then the Company shall so advise all
Holders of Registrable Securities and the number of shares of Registrable
Securities that may be included in the registration and underwriting shall be
allocated among all Holders thereof in proportion, as nearly as practicable, to
the respective amounts of Registrable Securities held by such Holders at the
time of filing the registration statement. No Registrable Securities excluded
from the underwriting by reason of




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the underwriter's marketing limitation shall be included in such registration.
To facilitate the allocation of shares in accordance with the above provisions,
the Company or the underwriters may round the number of shares allocated to any
Holder to the nearest 100 shares.

        If any Holder of Registrable Securities disapproves of the terms of the
underwriting, such person may elect to withdraw therefrom by written notice to
the Company and the managing underwriter. The Registrable Securities and/or
other securities so withdrawn shall also be withdrawn from registration, and
such Registrable Securities shall not be transferred in a public distribution
prior to one hundred eighty (180) days after the effective date of such
registration.

        1.6 Company Registration.

            (a) Notice of Registration. If at any time or from time to time, the
Company shall determine to register any of its securities, either for its own
account or the account of a security holder or holders other than (i) a
registration relating solely to employee benefit plans, or (ii) a registration
relating solely to a Commission Rule 145 transaction, the Company will:

                (i) promptly give to each Holder written notice thereof; and

                (ii) include in such registration (and any related qualification
under blue sky laws or other compliance), and in any underwriting involved in
such registration, all the Registrable Securities specified in a written request
or requests received within twenty (20) days after receipt of such written
notice from the Company by any Holder, but only to the extent that such
inclusion will not diminish the number of securities included by the Company or
by holders of the Company's securities who have demanded such registration.

            (b) Underwriting. If the registration of which the Company gives
notice is for a registered public offering involving an underwriting, the
Company shall so advise the Holders as a part of the written notice given
pursuant to Section 1.6(a)(i). In such event, the right of any Holder to
registration pursuant to Section 1.6 shall be conditioned upon such Holder's
participation in such underwriting and the inclusion of Registrable Securities
in the underwriting to the extent provided herein. All Holders proposing to
distribute their securities through such underwriting shall (together with the
Company and the other holders distributing their securities through such
underwriting) enter into an underwriting agreement in customary form with the
managing underwriter selected for such underwriting by the Company (or by the
holders who have demanded such registration). Notwithstanding any other
provision of this Section 1.6, if the managing underwriter determines that
marketing factors require a limitation of the number of shares to be
underwritten, the managing underwriter may limit the Registrable Securities to
be included in such registration to a minimum of 30% of the total shares to be
included in such underwriting or exclude them entirely in the case of the
Company's initial public offering. The Company shall so advise all Holders and
the other holders distributing their securities through such underwriting
pursuant to piggyback registration rights similar to this Section 1.6, and the
number of shares of Registrable Securities and other securities that may be
included in the registration and underwriting shall be first allocated among all
Preferred Purchasers in proportion, as nearly as practicable, to the respective
amounts of Registrable Securities held by such Preferred Purchasers at the time
of filing the registration statement, and after satisfaction of the requirements
of the Preferred Purchasers, the remaining shares that may be included in the




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registration and underwriting shall be allocated among the Founders in
proportion, as nearly as practicable, to the respective amounts of Registrable
Securities held by such Founders at the time of filing of the registration
statement. To facilitate the allocation of shares in accordance with the above
provisions, the Company or the underwriters may round the number of shares
allocated to any Holder or other holder to the nearest 100 shares. If any Holder
or other holder disapproves of the terms of any such underwriting, he or she may
elect to withdraw therefrom by written notice to the Company and the managing
underwriter. Any securities withdrawn from such underwriting shall be withdrawn
from such registration, and shall not be transferred in a public distribution
prior to one hundred eighty (180) days after the effective date of the
registration statement relating thereto (the "Lock-Up Period"); provided,
however, that if such registration is not the Company's initial public offering
such Lock-Up Period shall be one hundred twenty (120) days unless the managing
underwriter determines that marketing factors require a longer period in which
case the Lock-Up period shall be specified by the managing underwriter but shall
not exceed one hundred eighty (180) days.

            (c) Right to Terminate Registration. The Company shall have the
right to terminate or withdraw any registration initiated by it under this
Section 1.6 prior to the effectiveness of such registration, whether or not any
Holder has elected to include securities in such registration.

        1.7 Registration on Form S-3.

            (a) If Initiating Holders request that the Company file a
registration statement on Form S-3 (or any successor form to Form S-3) for a
public offering of shares of the Registrable Securities, the reasonably
anticipated aggregate price to the public of which, net of underwriting
discounts and commissions, would exceed $1,000,000, and the Company is a
registrant entitled to use Form S-3 to register the Registrable Securities for
such an offering, the Company shall use its best efforts to cause such
Registrable Securities to be registered for the offering on such form; provided,
however, that the Company shall not be required to effect more than one
registration pursuant to this Section 1.7 in any twelve (12) month period. The
Company will (i) promptly give written notice of the proposed registration to
all other Holders, and (ii) as soon as practicable, use its best efforts to
effect such registration (including, without limitation, the execution of an
undertaking to file post-effective amendments, appropriate qualification under
applicable blue sky or other state securities laws and appropriate compliance
with applicable regulations issued under the Securities Act and any other
governmental requirements or regulations) as may be so requested and as would
permit or facilitate the sale and distribution of all or such portion of such
Registrable Securities as are specified in such request, together with all or
such portion of the Registrable Securities of any Holder or Holders joining in
such request as are specified in a written request received by the Company
within twenty (20) days after receipt of such written notice from the Company.
The substantive provisions of Section 1.5(b) shall be applicable to each
registration initiated under this Section 1.7.

            (b) Notwithstanding the foregoing, the Company shall not be
obligated to take any action pursuant to this Section 1.7: (i) in any particular
jurisdiction in which the Company would be required to execute a general consent
to service of process in effecting such registration, qualification or
compliance unless the Company is already subject to service in such jurisdiction
and except as may be required by the Securities Act, (ii) during the period
ending on a




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date three (3) months following the effective date of a registration statement
(other than with respect to a registration statement relating to a Rule 145
transaction, an offering solely to employees or any other registration which is
not appropriate for the registration of Registrable Securities), or (iii) if the
Company shall furnish to such Holder a certificate signed by the President of
the Company stating that, in the good faith judgment of the Board of Directors,
it would be seriously detrimental to the Company or its shareholders for
registration statements to be filed in the near future, then the Company's
obligation to use its best efforts to file a registration statement shall be
deferred for a single period not to exceed one hundred twenty (120) days from
the receipt of the request to file such registration by such Holder or Holders.

        1.8 Limitations on Subsequent Registration Rights. From and after the
date of this Agreement, the Company shall not enter into any agreement granting
any holder or prospective holder of any securities of the Company registration
rights with respect to such securities unless such holder derives its rights as
an additional Holder hereunder, or such shares or securities are entitled to be
included in registrations only to the extent that the inclusion of such
securities will not diminish the amount of Holder's Registrable Securities that
are included.

        1.9 Expenses of Registration. All Registration Expenses incurred in
connection with any registration pursuant to Sections 1.5, 1.6 or 1.7 and the
reasonable cost of one special legal counsel to represent all of the Holders
together in any such registration shall be borne by the Company, provided that
the Company shall not be required to pay the Registration Expenses of any
registration proceeding begun pursuant to Section 1.5, the request of which has
been subsequently withdrawn by the Initiating Holders. In such case, the Holders
of Registrable Securities to have been registered shall bear all such
Registration Expenses pro rata on the basis of the number of shares to have been
registered unless the Holders of a majority of the Registrable Securities agree
to forfeit their right to one demand registration pursuant to Section 1.5.
Notwithstanding the foregoing, however, if at the time of the withdrawal, the
Holders have learned of a material adverse change in the condition, business or
prospects of the Company from that known to the Holders at the time of their
request, of which the Company had knowledge at the time of the request, then the
Holders shall not be required to pay any of said Registration Expenses or to
forfeit the right to one demand registration.

        1.10 Registration Procedures. In the case of each registration,
qualification or compliance effected by the Company pursuant to this Section 1,
the Company will keep each Holder advised in writing as to the initiation of
each registration, qualification and compliance and as to the completion
thereof. At its expense the Company will:

             (a) Prepare and file with the Commission a registration statement
with respect to such securities and use its best efforts to cause such
registration statement to become and remain effective for at least one hundred
eighty (120) days or until the distribution described in the registration
statement has been completed; and

             (b) Furnish to the Holders participating in such registration and
to the underwriters of the securities being registered such reasonable number of
copies of the registration statement, preliminary prospectus, final prospectus
and such other documents as such underwriters may reasonably request in order to
facilitate the public offering of such securities.




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        1.11 Indemnification.

             (a) The Company will indemnify each Holder, each of its officers
and directors and partners, and each person controlling such Holder within the
meaning of Section 15 of the Securities Act, with respect to which registration,
qualification or compliance has been effected pursuant to this Section 1, and
each underwriter, if any, and each person who controls any underwriter within
the meaning of Section 15 of the Securities Act, against all expenses, claims,
losses, damages or liabilities (or actions in respect thereof), including any of
the foregoing incurred in settlement of any litigation, commenced or threatened,
arising out of or based on any untrue statement (or alleged untrue statement) of
a material fact contained in any registration statement, prospectus, offering
circular or other document, or any amendment or supplement thereto, incident to
any such registration, qualification or compliance, or based on any omission (or
alleged omission) to state therein a material fact required to be stated therein
or necessary to make the statements therein, in light of the circumstances in
which they were made, not misleading, or any violation by the Company of any
rule or regulation promulgated under the Securities Act applicable to the
Company in connection with any such registration, qualification or compliance,
and the Company will reimburse each such Holder, each of its officers and
directors, and each person controlling such Holder, each such underwriter and
each person who controls any such underwriter, for any legal and any other
expenses reasonably incurred in connection with investigating, preparing or
defending any such claim, loss, damage, liability or action, provided that the
Company will not be liable in any such case to the extent that any such claim,
loss, damage, liability or expense arises out of or is based on any untrue
statement or omission or alleged untrue statement or omission, made in reliance
upon and in conformity with written information furnished to the Company by an
instrument duly executed by such Holder, controlling person or underwriter and
stated to be specifically for use therein.

             (b) Each Holder will, if Registrable Securities held by such Holder
are included in the securities as to which such registration, qualification or
compliance is being effected, indemnify the Company, each of its directors and
officers, each underwriter, if any, of the Company's securities covered by such
a registration statement, each person who controls the Company or such
underwriter within the meaning of Section 15 of the Securities Act, and each
other such Holder, each of its officers and directors and each person
controlling such Holder within the meaning of Section 15 of the Securities Act,
against all claims, losses, damages and liabilities (or actions in respect
thereof) arising out of or based on any untrue statement (or alleged untrue
statement) of a material fact contained in any such registration statement,
prospectus, offering circular or other document, or any omission (or alleged
omission) to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, and will reimburse the
Company, such Holders, such directors, officers, persons, underwriters or
control persons for any legal or any other expenses reasonably incurred in
connection with investigating or defending any such claim, loss, damage,
liability or action, in each case to the extent, but only to the extent, that
such untrue statement (or alleged untrue statement) or omission (or alleged
omission) is made in such registration statement, prospectus, offering circular
or other document in reliance upon and in conformity with written information
furnished to the Company by an instrument duly executed by such Holder and
stated to be specifically for use therein; provided, however, that the liability
of a Holder for indemnification under this Section 1.11(b) shall not exceed the
net proceeds from the offering received by such Holder.




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             (c) Each party entitled to indemnification under this Section 1.11
(the "Indemnified Party") shall give notice to the party required to provide
indemnification (the "Indemnifying Party") promptly after such Indemnified Party
has actual knowledge of any claim as to which indemnity may be sought, and shall
permit the Indemnifying Party to assume the defense of any such claim or any
litigation resulting therefrom, provided that counsel for the Indemnifying
Party, who shall conduct the defense of such claim or litigation, shall be
approved by the Indemnified Party (whose approval shall not unreasonably be
withheld), and the Indemnified Party may participate in such defense at such
party's expense, and provided further that the failure of any Indemnified Party
to give notice as provided herein shall not relieve the Indemnifying Party of
its obligations under this Section 1 unless the failure to give such notice is
materially prejudicial to an Indemnifying Party's ability to defend such action.
No Indemnifying Party, in the defense of any such claim or litigation, shall,
except with the consent of each Indemnified Party, consent to entry of any
judgment or enter into any settlement which does not include as an unconditional
term thereof the giving by the claimant or plaintiff to such Indemnified Party
of a release from all liability in respect to such claim or litigation.

        1.12 Information by Holder. The Holder or Holders of Registrable
Securities included in any registration shall furnish to the Company such
information regarding such Holder or Holders, the Registrable Securities held by
them and the distribution proposed by such Holder or Holders as the Company may
request in writing and as shall be required in connection with any registration,
qualification or compliance referred to in this Section 1.

        1.13 Rule 144 Reporting. With a view to making available the benefits of
certain rules and regulations of the Commission which may at any time permit the
sale of the Restricted Securities to the public without registration, after such
time as a public market exists for the Common Stock of the Company, the Company
agrees to use its best efforts to:

             (a) Make and keep public information available, as those terms are
understood and defined in Rule 144 under the Securities Act, at all times after
the effective date that the Company becomes subject to the reporting
requirements of the Securities Act or the Securities Exchange Act of 1934, as
amended (the "Exchange Act");

             (b) File with the Commission in a timely manner all reports and
other documents required of the Company under the Securities Act and the
Exchange Act (at any time after it has become subject to such reporting
requirements); and

             (c) So long as an Investor owns any Restricted Securities, to
furnish to the Investor forthwith upon request a written statement by the
Company as to its compliance with the reporting requirements of said Rule 144
(at any time after ninety (90) days after the effective date of the first
registration statement filed by the Company for an offering of its securities to
the general public), and of the Securities Act and the Exchange Act (at any time
after it has become subject to such reporting requirements), a copy of the most
recent annual or quarterly report of the Company, and such other reports and
documents of the Company and other information in the possession of or
reasonably obtainable by the Company as an Investor may reasonably request in
availing itself of any rule or regulation of the Commission allowing an Investor
to sell any such securities without registration.




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   11

        1.14 Transfer of Registration Rights. The rights to cause the Company to
register securities granted Investors under Sections 1.5, 1.6 and 1.7 may be
assigned to a transferee or assignee in connection with any transfer or
assignment of Registrable Securities by an Investor (together with any
affiliate); provided, that (a) such transfer may otherwise be effected in
accordance with applicable securities laws, (b) notice of such assignment is
given to the Company, and (c) such transferee or assignee (i) is an affiliate of
such Investor or a constituent partner (including limited partners) of such
Investor, or (ii) acquires from such Investor the lesser of (a) 100,000 or more
shares of Restricted Securities (as appropriately adjusted for stock splits and
the like) or (b) all of the Restricted Securities then owned by such Investor.

        1.15 Standoff Agreement. Each Holder agrees in connection with the
initial public offering of the Company's securities that, upon request of the
Company or the underwriters managing any underwritten initial public offering of
the Company's securities, not to sell, make any short sale of, loan, grant any
option for the purchase of, or otherwise dispose of any Registrable Securities
(other than those included in the registration) without the prior written
consent of the Company or such underwriters, as the case may be, for such period
of time (not to exceed one hundred eighty (180) days from the effective date of
such registration) as may be requested by the Company or such managing
underwriters; provided, however, that the officers and directors of the Company
who own stock of the Company also agree to such restrictions.

        1.16 Termination of Rights. No Holder shall be entitled to exercise any
right provided for in this Section 1:

             (a) after five (5) years following the consummation of the sale of
securities pursuant to a registration statement filed by the Company under the
Act in connection with the initial firm commitment underwritten offering of its
securities to the general public, or

             (b) on or after the closing of a public offering of the Common
Stock of the Company when all shares of the Holder's Registrable Securities may
be sold under Rule 144 during any 90-day period; provided, however, that the
provisions of this subsection (b) shall not apply where the Holder owns more
than two percent (2%) of the Company's outstanding stock until such time as such
Holder owns less than two percent (2%) of the outstanding stock.


                                    SECTION 2

                             Right of Participation

        2.1 Purchasers' Right of Participation.

             (a) Right of Participation. Subject to the terms and conditions
contained in this Section 2.1, the Company hereby grants to each Major Purchaser
the right of participation to purchase its Pro Rata Portion of any New
Securities (as defined in subsection 2.1(b)) which the Company may, from time to
time, propose to sell and issue. A Major Purchaser's "Pro Rata Portion" for
purposes of this Section 2.1 is the ratio that (x) the sum of the number of
shares of the Company's Common Stock then held by such Major Purchaser and the
number of shares of the Company's Common Stock issuable upon conversion of the
Preferred Stock then held by such Major Purchaser, bears to (y) the sum of the
total number of shares of the Company's Common Stock then outstanding, the
number of shares of the Company's Common Stock




                                      -11-
   12

issuable upon the exercise of any issued and outstanding rights, options or
warrants, and the number of shares of the Company's Common Stock issuable upon
conversion of the then outstanding Preferred Stock.

             (b) Definition of New Securities. Except as set forth below, "New
Securities" shall mean any shares of capital stock of the Company, including
Common Stock and Preferred Stock, whether authorized or not, and rights, options
or warrants to purchase said shares of Common Stock or Preferred Stock, and
securities of any type whatsoever that are, or may become, convertible into said
shares of Common Stock or Preferred Stock. Notwithstanding the foregoing, "New
Securities" does not include (i) the Common Shares, the Preferred Shares or the
Conversion Shares, (ii) securities offered to the public generally pursuant to a
registration statement under the Securities Act, (iii) securities issued
pursuant to the acquisition of another corporation by the Company by merger,
purchase of substantially all of the assets or shares or other reorganization
whereby the Company or its shareholders own not less than a majority of the
voting power of the surviving or successor corporation, (iv) shares of the
Company's Common Stock or related options or warrants convertible into or
exercisable for such Common Stock issued to employees, officers and directors
of, and consultants to, the Company, pursuant to any arrangement approved by the
Board of Directors of the Company, (v) shares of the Company's Common Stock or
related options or warrants convertible into or exercisable for such Common
Stock issued to customers and vendors of the Company pursuant to any arrangement
unanimously approved by the Board of Directors of the Company; (vi) shares of
the Company's Common Stock or related options convertible into or exercisable
for such Common Stock issued to banks, commercial lenders, lessors and other
financial institutions in connection with the borrowing of money or the leasing
of equipment by the Company, (vii) stock issued pursuant to any rights or
agreements, including, without limitation, convertible securities, options and
warrants, provided that the Company shall have complied with the rights of
participation established by this Section 2.1 with respect to the initial sale
or grant by the Company of such rights or agreements, or (viii) shares of
capital stock issued in connection with any stock split, stock dividend or
recapitalization by the Company.

             (c) Notice of Right. In the event the Company proposes to undertake
an issuance of New Securities, it shall give each Purchaser written notice of
its intention, describing the type of New Securities and the price and terms
upon which the Company proposes to issue the same. Each Purchaser shall have
twenty (20) days from the date of receipt of any such notice to agree to
purchase shares of such New Securities (up to the amount referred to in
subsection 2.1(a)), for the price and upon the terms specified in the notice, by
giving written notice to the Company and stating therein the quantity of New
Securities to be purchased.

             (d) Exercise of Right. If any Purchaser exercises its right of
participation under this Agreement, the closing of the purchase of the New
Securities with respect to which such right has been exercised shall take place
within ninety (90) calendar days after the Purchaser gives notice of such
exercise, which period of time shall be extended in order to comply with
applicable laws and regulations. Upon exercise of such right of participation,
the Company and the Purchaser shall be legally obligated to consummate the
purchase contemplated thereby and shall use their best efforts to secure any
approvals required in connection therewith.




                                      -12-
   13

             (e) Lapse and Reinstatement of Right. In the event a Purchaser
fails to exercise the right of participation provided in this Section 2.1 within
said twenty (20) day period, the Company shall have ninety (90) days thereafter
to sell or enter into an agreement (pursuant to which the sale of New Securities
covered thereby shall be closed, if at all, within sixty (60) days from the date
of said agreement) to sell the New Securities not elected to be purchased by
such Purchaser at the price and upon the terms no more favorable to the
purchasers of such securities than specified in the Company's notice. In the
event the Company has not sold the New Securities or entered into an agreement
to sell the New Securities within said ninety (90) day period (or sold and
issued New Securities in accordance with the foregoing within sixty (60) days
from the date of said agreement), the Company shall not thereafter issue or sell
any New Securities without first offering such securities to the Purchasers in
the manner provided above.

             (f) Assignment. The right of the Purchasers to purchase any part of
the New Securities may be assigned in whole or in part to any partner,
subsidiary, affiliate or shareholder of a Purchaser, or other persons or
organizations who acquire the lesser of (i) 100,000 or more shares of Restricted
Securities (as adjusted for stock splits and the like) or (ii) all of the
Restricted Securities then owned by such Purchaser.

        2.2 Termination of Participation Right. The rights of participation
granted under Section 2.1 of this Agreement shall terminate on and be of no
further force or effect upon the earlier of (i) the consummation of the
Company's sale of its Common Stock in an underwritten public offering pursuant
to an effective registration statement filed under the Securities Act
immediately subsequent to which the Company shall be obligated to file annual
and quarterly reports with the Commission pursuant to Section 13 or 15(d) of the
Exchange Act or (ii) the registration by the Company of a class of its equity
securities under Section 12(b) or 12(g) of the Exchange Act.


                                    SECTION 3

                                  Miscellaneous

        3.1 Assignment. Except as otherwise provided in this Agreement, the
terms and conditions of this Agreement shall inure to the benefit of and be
binding upon the respective successors and assigns of the parties to this
Agreement.

        3.2 Third Parties. Nothing in this Agreement, express or implied, is
intended to confer upon any party, other than the parties to this Agreement, and
their respective successors and assigns, any rights, remedies, obligations or
liabilities under or by reason of this Agreement, except as expressly provided
in this Agreement.

        3.3 Governing Law. This Agreement shall be governed by and construed
under the laws of the State of California in the United States of America
without giving effect to the conflicts of laws principles thereof.

        3.4 Counterparts. This Agreement may be executed in counterparts, each
of which shall be deemed an original, but all of which together shall constitute
one and the same instrument.




                                      -13-
   14

        3.5 Notices. Any notice required or permitted by this Agreement shall be
in writing and shall be sent by prepaid registered or certified mail, return
receipt requested, or otherwise delivered by hand or by messenger addressed to
the other party at the address shown below or at such other address for which
such party gives notice under this Agreement. Such notice shall be deemed to
have been given when delivered if delivered personally, or, if sent by mail, at
the earlier of its receipt or three (3) days after deposit in the mail.

        3.6 Severability. If one or more provisions of this Agreement are held
to be unenforceable under applicable law, portions of such provisions, or such
provisions in their entirety, to the extent necessary, shall be severed from
this Agreement, and the balance of this Agreement shall be enforceable in
accordance with its terms.

        3.7 Amendment and Waiver. Any provision of this Agreement may be amended
or waived with the written consent of the Company and the Holders of at least a
majority of the outstanding shares of the Registrable Securities, so long as the
effect is to treat all Holders equally. ****************************************
Any amendment or waiver effected in accordance with this paragraph shall be
binding upon each Holder of Registrable Securities and the Company. In addition,
the Company may waive performance of any obligation owing to it, as to some or
all of the Holders of Registrable Securities, or agree to accept alternatives to
such performance, without obtaining the consent of any Holder of Registrable
Securities. In the event that an underwriting agreement is entered into between
the Company and any Holder, and such underwriting agreement contains terms
differing from this Agreement, as to any such Holder the terms of such
underwriting agreement shall govern.

        3.8 Effect of Amendment or Waiver. The Investors and their successors
and assigns acknowledge that by the operation of Section 3.7 of this Agreement
the holders of a majority of the outstanding Registrable Securities, acting in
conjunction with the Company, will have the right and power to diminish or
eliminate any or all rights or increase any or all obligations pursuant to this
Agreement.

        3.9 Rights of Holders. Each holder of Registrable Securities shall have
the absolute right to exercise or refrain from exercising any right or rights
that such holder may have by reason of this Agreement, including, without
limitation, the right to consent to the waiver or modification of any obligation
under this Agreement, and such holder shall not incur any liability to any other
holder of any securities of the Company as a result of exercising or refraining
from exercising any such right or rights.

        3.10 Delays or Omissions. No delay or omission to exercise any right,
power or remedy accruing to any party to this Agreement, upon any breach or
default of the other party, shall impair any such right, power or remedy of such
non-breaching party nor shall it be construed to be a waiver of any such breach
or default, or an acquiescence therein, or of or in any




                                      -14-
   15

similar breach or default thereafter occurring; nor shall any waiver of any
single breach or default be deemed a waiver of any other breach or default
theretofore or thereafter occurring. Any waiver, permit, consent or approval of
any kind or character on the part of any party of any breach or default under
this Agreement, or any waiver on the part of any party of any provisions or
conditions of this Agreement, must be made in writing and shall be effective
only to the extent specifically set forth in such writing. All remedies, either
under this Agreement, or by law or otherwise afforded to any holder, shall be
cumulative and not alternative.

        3.11 Aggregation of Stock. All Registrable Securities held or acquired
by affiliated entities or persons shall be aggregated together for the purpose
of determining the availability of any rights under this Agreement.





                            [SIGNATURE PAGE FOLLOWS]




                                      -15-
   16

        IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year first above written.


COMPANY:

PDF SOLUTIONS, INC.,
a California corporation

By: /s/ John K. Kibarian
    -------------------------------------------------------
    John K. Kibarian, President and Chief Executive Officer



FOUNDERS:

/s/ John K. Kibarian
- -------------------------------------
JOHN K. KIBARIAN


/s/ Kimon Michaels
- -------------------------------------
KIMON MICHAELS


/s/ Thomas Cobourn
- -------------------------------------
THOMAS COBOURN


/s/ Howard Read
- -------------------------------------
HOWARD READ




                                SIGNATURE PAGE TO
                  FIRST AMENDED AND RESTATED RIGHTS AGREEMENT



   17

SERIES A AND SERIES B HOLDERS:


U.S. VENTURE PARTNERS IV, L.P.

By: Presidio Management Group IV, L.P.
      Its General Partner


By: /s/ PHILIP M. YOUNG
   -----------------------------------
   Name:  Philip M. Young
   Title: General Partner

        2180 Sand Hill Road, Suite 300
        Menlo Park, CA 94025


SECOND VENTURES II, L.P.

By: Presidio Management Group IV, L.P.
       Its General Partner


By: /s/ PHILIP M. YOUNG
   -----------------------------------
   Name:  Philip M. Young
   Title: General Partner

        2180 Sand Hill Road, Suite 300
        Menlo Park, CA 94025


U.S.V.P. ENTREPRENEUR PARTNERS II, L.P.
A Delaware Limited Partnership

By: Presidio Management Group IV, L.P.
       Its General Partner


By: /s/ PHILIP M. YOUNG
   -----------------------------------
   Name:  Philip M. Young
   Title: General Partner

        2180 Sand Hill Road, Suite 300
        Menlo Park, CA 94025




                                SIGNATURE PAGE TO
                  FIRST AMENDED AND RESTATED RIGHTS AGREEMENT


   18

2180 ASSOCIATES FUND


By: /s/ JONATHON D. ROOT, M.D.
    ---------------------------------------
    Name:  Jonathon D. Root, M.D.
    Title: General Partner

        2180 Sand Hill Road, Suite 300
        Menlo Park, CA 94025


TELOS VENTURE PARTNERS, L.P.


By: /s/ BRUCE R. BOURBON
    ---------------------------------------
    Name:  Bruce R. Bourbon
    Title: Managing Member of the General
           Partner, Telos Management LLC

        2350 Mission College Blvd., Suite 1070
        Santa Clara, CA 95054


THE CASSIN FAMILY TRUST U/D/T/
DTD 1/31/96, BRENDAN J. AND ISABEL
B. CASSIN, TRUSTEES


By:________________________________________
   Name:
   Title:

        3000 Sand Hill Road, Building 3, Suite 210
        Menlo Park, CA 94025


CASSIN FAMILY PARTNERS,
A CALIFORNIA LIMITED PARTNERSHIP


By:________________________________________
   Name:
   Title:

        3000 Sand Hill Road, Building 3, Suite 210
        Menlo Park, CA 94025




                                SIGNATURE PAGE TO
                  FIRST AMENDED AND RESTATED RIGHTS AGREEMENT
   19

VLG INVESTMENTS 1995


By:________________________________________
   Name:
   Title:

        c/o Venture Law Group
        2800 Sand Hill Road
        Menlo Park, CA 94025


CRAIG W. JOHNSON


/s/ Craig W. Johnson
- -------------------------------------------
Craig W. Johnson

        c/o Venture Law Group
        2800 Sand Hill Road
        Menlo Park, CA 94025


PETER COHN


/s/ Peter Cohn
- -------------------------------------------
Peter Cohn

        c/o 1020 Marsh Road
        Menlo Park, CA 94025

PETER COHN, AS TRUSTEE OR THE
SUCCESSOR TRUSTEE OR TRUSTEES
U/A/D JUNE 29, 1995, AS AMENDED,
CREATING THE PETER COHN REVOCABLE TRUST


By: /s/ Peter Cohn
    ----------------------------------------

        1020 Marsh Road
        Menlo Park, CA 94025




                                SIGNATURE PAGE TO
                  FIRST AMENDED AND RESTATED RIGHTS AGREEMENT

   20

ORRICK, HERRINGTON & SUTCLIFFE LLP


By: /s/ Peter Cohn
   ----------------------------------------
   Peter Cohn
   Partner

        1020 Marsh Road
        Menlo Park, CA 94025


RICHARD M. LUCAS FOUNDATION


By: /s/ DONALD L. LUCAS
    ---------------------------------------
    Name:  Donald L. Lucas
    Title: Chairman of the Board

        3000 Sand Hill Road, Suite 3-210
        Menlo Park, CA 94025


ST. MARY'S COLLEGE OF CALIFORNIA


By:________________________________________
   Name:
   Title:

        1928 St Mary's Road
        Moraga, CA 94556


ST. FRANCIS GROWTH FUND


By:________________________________________
   Name:
   Title:

        San Francis High School
        1885 Miramonte Avenue
        Mountain View, CA 94049




                                SIGNATURE PAGE TO
                   FIRST AMENDED AND RESTATED RIGHTS AGREEMENT

   21

LARRY YOSHIDA

  /s/ LARRY YOSHIDA
- -------------------------------------------
      Larry Yoshida

            Address: I-3-20 Tamagawa-Bakuen
            Machida City, Tokyo 194-0041
            Japan

DONALD L. LUCAS PROFIT SHARING TRUST


By: /s/ DONALD L. LUCAS
    ---------------------------------------
    Name:  Donald L. Lucas
    Title: Successor Trustee

        Attn:  Donald L. Lucas
        3000 Sand Hill Road, #3-210
        Menlo Park, CA 94025
        (650) 854-4223




                                SIGNATURE PAGE TO
                  FIRST AMENDED AND RESTATED RIGHTS AGREEMENT


   22


RWI GROUP IV, L.P.
By:  RWI GROUP LLC
        Its General Partner


By: /s/ Donald A. Lucas
   --------------------------------
   Name: Donald A. Lucas
   Title: Managing Member

        Attn:  Donald A. Lucas
        720 University Ave., # 103
        Palo Alto, CA 94301
        (650) 833-4980


BRIAN BURR


/s/ BRIAN BURR
___________________________________________
Brian Burr

        c/o 1020 Marsh Road
            Menlo Park, CA 94025




                                SIGNATURE PAGE TO
                   FIRST AMENDED AND RESTATED RIGHTS AGREEMENT


   23


TETON CAPITAL COMPANY,
A CALIFORNIA LIMITED PARTNERSHIP


By: /s/ Donald L. Lucas
   ---------------------------------------
   Name: Donald L. Lucas
   Title: General Partner

        Attn:  Donald L. Lucas
        3000 Sand Hill Road, #3-210
        Menlo Park, CA 94025
        (650) 854-4223


THE RYDE REVOCABLE TRUST
dated 12/15/94


By: /s/ MAGNUS RYDE
   ---------------------------------------
   Name: Magnus Ryde
   Title: Trustee

        39 Winchester Drive
        Atherton, CA 94027
        (650) 329-9738


                                SIGNATURE PAGE TO
                   FIRST AMENDED AND RESTATED RIGHTS AGREEMENT