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                                                                  EXHIBIT 10.3.1


                               NASSDA CORPORATION
                             2001 STOCK OPTION PLAN
                             STOCK OPTION AGREEMENT

     Unless otherwise defined herein, the terms defined in the Plan shall have
the same defined meanings in this Option Agreement.

I.   NOTICE OF STOCK OPTION GRANT
     ----------------------------

[Optionee's Name and Address]


     The undersigned Optionee has been granted an Option to purchase Common
Stock of the Company, subject to the terms and conditions of the Plan and this
Option Agreement, as follows:

     Grant Number                       _________________________

     Date of Grant                      _________________________

     Vesting Commencement Date          _________________________

     Exercise Price per Share           $________________________

     Total Number of Shares Granted     _________________________

     Total Exercise Price               $________________________

     Type of Option:                    ___  Incentive Stock Option

                                        ___  Nonstatutory Stock Option

     Term/Expiration Date:              _________________________


     Vesting Schedule:
     ----------------

     This Option shall be exercisable, in whole or in part, according to the
following vesting schedule:

     25% of the Shares subject to the Option shall vest twelve months after the
Vesting Commencement Date, and 1/48 of the Shares subject to the Option shall
vest each month thereafter, subject to Optionee's continuing to be a Service
Provider on such dates.

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     Termination Period:
     -------------------

     This Option shall be exercisable for 45 days after Optionee ceases to be a
Service Provider. Upon Optionee's death or disability, this Option may be
exercised for such longer period as provided in the Plan. In no event may
Optionee exercise this Option after the Term/Expiration Date as provided above.

II.  AGREEMENT
     ---------

     1.   Grant of Option. The Plan Administrator of the Company hereby grants
          ---------------
to the Optionee named in the Notice of Grant (the "Optionee"), an option (the
"Option") to purchase the number of Shares set forth in the Notice of Grant, at
the exercise price per Share set forth in the Notice of Grant (the "Exercise
Price"), and subject to the terms and conditions of the Plan, which is
incorporated herein by reference. Subject to Section 13(c) of the Plan, in the
event of a conflict between the terms and conditions of the Plan and this Option
Agreement, the terms and conditions of the Plan shall prevail.

          If designated in the Notice of Grant as an Incentive Stock Option
("ISO"), this Option is intended to qualify as an Incentive Stock Option as
defined in Section 422 of the Code. Nevertheless, to the extent that it exceeds
the $100,000 rule of Code Section 422(d), this Option shall be treated as a
Nonstatutory Stock Option ("NSO").

     2.   Exercise of Option.
          ------------------

          (a)  Right to Exercise. This Option shall be exercisable during its
               -----------------
term in accordance with the Vesting Schedule set out in the Notice of Grant and
with the applicable provisions of the Plan and this Option Agreement.

          (b)  Method of Exercise. This Option shall be exercisable by delivery
               ------------------
of an exercise notice in the form attached as Exhibit A (the "Exercise Notice")
                                              ---------
which shall state the election to exercise the Option, the number of Shares with
respect to which the Option is being exercised, and such other representations
and agreements as may be required by the Company. The Exercise Notice shall be
accompanied by payment of the aggregate Exercise Price as to all Exercised
Shares. This Option shall be deemed to be exercised upon receipt by the Company
of such fully executed Exercise Notice accompanied by the aggregate Exercise
Price.

               No Shares shall be issued pursuant to the exercise of an Option
unless such issuance and such exercise complies with Applicable Laws. Assuming
such compliance, for income tax purposes the Shares shall be considered
transferred to the Optionee on the date on which the Option is exercised with
respect to such Shares.

     3.   Optionee's Representations. In the event the Shares have not been
          --------------------------
registered under the Securities Act of 1933, as amended, at the time this Option
is exercised, the Optionee shall, if required by the Company, concurrently with
the exercise of all or any portion of this Option, deliver to the Company his or
her Investment Representation Statement in the form attached hereto as Exhibit
                                                                       -------
B.
-


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     4.   Method of Payment. Payment of the aggregate Exercise Price shall be by
          -----------------
any of the following, or a combination thereof, at the election of the Optionee:

          (a)  cash or check;

          (b)  consideration received by the Company under a formal cashless
exercise program adopted by the Company in connection with the Plan; or

          (c)  surrender of other Shares which, (i) in the case of Shares
acquired upon exercise of an option, have been owned by the Optionee for more
than six (6) months on the date of surrender, and (ii) have a Fair Market Value
on the date of surrender equal to the aggregate Exercise Price of the Exercised
Shares.

          (d)  with the Administrator's consent, delivery of Optionee's
promissory note (the "Note") in the form attached hereto as Exhibit C, in the
                                                            ---------
amount of the aggregate Exercise Price of the Exercised Shares together with the
execution and delivery by the Optionee of the Security Agreement attached hereto
as Exhibit D. The Note shall bear interest at the "applicable federal rate"
   ---------
prescribed under the Code and its regulations at time of purchase, and shall be
secured by a pledge of the Shares purchased by the Note pursuant to the Security
Agreement.

     5.   Restrictions on Exercise. This Option may not be exercised until such
          ------------------------
time as the Plan has been approved by the stockholders of the Company, or if the
issuance of such Shares upon such exercise or the method of payment of
consideration for such shares would constitute a violation of any Applicable
Law.

     6.   Non-Transferability of Option. This Option may not be transferred in
          -----------------------------
any manner otherwise than by will or by the laws of descent or distribution and
may be exercised during the lifetime of Optionee only by Optionee. The terms of
the Plan and this Option Agreement shall be binding upon the executors,
administrators, heirs, successors and assigns of the Optionee.

     7.   Term of Option. This Option may be exercised only within the term set
          --------------
out in the Notice of Grant, and may be exercised during such term only in
accordance with the Plan and the terms of this Option.

     8.   Tax Consequences. Set forth below is a brief summary as of the date of
          ----------------
this Option of some of the federal tax consequences of exercise of this Option
and disposition of the Shares. THIS SUMMARY IS NECESSARILY INCOMPLETE, AND THE
TAX LAWS AND REGULATIONS ARE SUBJECT TO CHANGE. THE OPTIONEE SHOULD CONSULT A
TAX ADVISER BEFORE EXERCISING THIS OPTION OR DISPOSING OF THE SHARES.

          (a)  Exercise of ISO. If this Option qualifies as an ISO, there will
               ---------------
be no regular federal income tax liability upon the exercise of the Option,
although the excess, if any, of the Fair Market Value of the Shares on the date
of exercise over the Exercise Price will be treated as an adjustment to the
alternative minimum tax for federal tax purposes and may subject the Optionee to
the alternative minimum tax in the year of exercise.

          (b)  Exercise of Nonstatutory Stock Option. There may be a regular
               -------------------------------------
federal income tax liability upon the exercise of a Nonstatutory Stock Option.
The Optionee will be treated


                                       -3-

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as having received compensation income (taxable at ordinary income tax rates)
equal to the excess, if any, of the Fair Market Value of the Shares on the date
of exercise over the Exercise Price. If Optionee is an Employee or a former
Employee, the Company will be required to withhold from Optionee's compensation
or collect from Optionee and pay to the applicable taxing authorities an amount
in cash equal to a percentage of this compensation income at the time of
exercise, and may refuse to honor the exercise and refuse to deliver Shares if
such withholding amounts are not delivered at the time of exercise.

          (c)  Disposition of Shares. In the case of an NSO, if Shares are held
               ---------------------
for at least one year, any gain realized on disposition of the Shares will be
treated as long-term capital gain for federal income tax purposes. In the case
of an ISO, if Shares transferred pursuant to the Option are held for at least
one year after exercise and of at least two years after the Date of Grant, any
gain realized on disposition of the Shares will also be treated as long-term
capital gain for federal income tax purposes. If Shares purchased under an ISO
are disposed of within one year after exercise or two years after the Date of
Grant, any gain realized on such disposition will be treated as compensation
income (taxable at ordinary income rates) to the extent of the difference
between the Exercise Price and the lesser of (1) the Fair Market Value of the
Shares on the date of exercise, or (2) the sale price of the Shares. Any
additional gain will be taxed as capital gain, short-term or long-term depending
on the period that the ISO Shares were held.

          (d)  Notice of Disqualifying Disposition of ISO Shares. If the Option
               -------------------------------------------------
granted to Optionee herein is an ISO, and if Optionee sells or otherwise
disposes of any of the Shares acquired pursuant to the ISO on or before the
later of (1) the date two years after the Date of Grant, or (2) the date one
year after the date of exercise, the Optionee shall immediately notify the
Company in writing of such disposition. Optionee agrees that Optionee may be
subject to income tax withholding by the Company on the compensation income
recognized by the Optionee.

     9.   Entire Agreement; Governing Law. The Plan is incorporated herein by
          -------------------------------
reference. The Plan and this Option Agreement constitute the entire agreement of
the parties with respect to the subject matter hereof and supersede in their
entirety all prior undertakings and agreements of the Company and Optionee with
respect to the subject matter hereof, and may not be modified adversely to the
Optionee's interest except by means of a writing signed by the Company and
Optionee. This agreement is governed by and construed in accordance with the
laws of the State of California applicable to contracts entered into and wholly
to be performed within the State of California residents.

     10.  No Guarantee of Continued Service. OPTIONEE ACKNOWLEDGES AND AGREES
          ---------------------------------
THAT THE VESTING OF SHARES PURSUANT TO THE VESTING SCHEDULE HEREOF IS EARNED
ONLY BY CONTINUING AS A SERVICE PROVIDER AT THE WILL OF THE COMPANY (NOT THROUGH
THE ACT OF BEING HIRED, BEING GRANTED THIS OPTION OR ACQUIRING SHARES
HEREUNDER). OPTIONEE FURTHER ACKNOWLEDGES AND AGREES THAT THIS AGREEMENT, THE
TRANSACTIONS CONTEMPLATED HEREUNDER AND THE VESTING SCHEDULE SET FORTH HEREIN DO
NOT CONSTITUTE AN EXPRESS OR IMPLIED PROMISE OF CONTINUED ENGAGEMENT AS A
SERVICE PROVIDER FOR THE VESTING PERIOD, FOR ANY PERIOD, OR AT ALL, AND SHALL
NOT INTERFERE IN ANY WAY WITH OPTIONEE'S RIGHT OR THE


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COMPANY'S RIGHT TO TERMINATE OPTIONEE'S RELATIONSHIP AS A SERVICE PROVIDER AT
ANY TIME, WITH OR WITHOUT CAUSE.

     Optionee acknowledges receipt of a copy of the Plan and represents that he
or she is familiar with the terms and provisions thereof, and hereby accepts
this Option subject to all of the terms and provisions thereof. Optionee has
reviewed the Plan and this Option in their entirety, has had an opportunity to
obtain the advice of counsel prior to executing this Option and fully
understands all provisions of the Option. Optionee hereby agrees to accept as
binding, conclusive and final all decisions or interpretations of the
Administrator upon any questions arising under the Plan or this Option. Optionee
further agrees to notify the Company upon any change in the residence address
indicated below.

NASSDA CORPORATION


____________________________________
By

____________________________________
Title

OPTIONEE'S ACCEPTANCE AND ACKNOWLEDGMENT

Dated:______________________________         ___________________________________
                                             Residential Address

____________________________________         ___________________________________
Optionee's Signature                         City, State, Zip Code

__________  I hereby acknowledge that I am not legally married as of the date of
            this Agreement.

__________  I hereby acknowledge that I am legally married as of the date of
            this Agreement and, if applicable, by executing this Agreement, my
            spouse agrees to be bound by all the terms and conditions of this
            Agreement.


____________________________________
Spouse's Signature

SPOUSAL SIGNATURE IS REQUIRED FOR RESIDENTS OF COMMUNITY PROPERTY STATES:
ARIZONA, CALIFORNIA, IDAHO, LOUISIANA, NEVADA, NEW MEXICO, TEXAS, WASHINGTON AND
WISCONSIN.

THIS OPTION WILL BECOME EFFECTIVE UPON RECEIPT BY THE COMPANY OF ONE FULLY
EXECUTED COPY OF THIS AGREEMENT


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                                    EXHIBIT A
                                    ---------

                             2001 STOCK OPTION PLAN

                                 EXERCISE NOTICE

NASSDA Corporation
2975 Scott Boulevard, Suite 110
Santa Clara, CA 95054

Attention: Chief Executive Officer

     1.   Exercise of Option. Effective as of today, ___________, 20__, the
          ------------------
undersigned ("Optionee") hereby elects to exercise Optionee's option to purchase
_________ shares of the Common Stock (the "Shares") of NASSDA Corporation (the
"Company") under and pursuant to the 2001 Stock Option Plan (the "Plan") and the
Stock Option Agreement dated ________, 20___ (the "Option Agreement").

     2.   Delivery of Payment. Purchaser herewith delivers to the Company the
          -------------------
full purchase price of the Shares, as set forth in the Option Agreement.

     3.   Representations of Optionee. Optionee acknowledges that Optionee has
          ---------------------------
received, read and understood the Plan and the Option Agreement and agrees to
abide by and be bound by their terms and conditions.

     4.   Rights as Stockholder. Until the issuance of the Shares (as evidenced
          ---------------------
by the appropriate entry on the books of the Company or of a duly authorized
transfer agent of the Company), no right to vote or receive dividends or any
other rights as a stockholder shall exist with respect to the Optioned Stock,
notwithstanding the exercise of the Option. The Shares shall be issued to the
Optionee as soon as practicable after the Option is exercised. No adjustment
shall be made for a dividend or other right for which the record date is prior
to the date of issuance except as provided in Section 11 of the Plan.

     5.   Tax Consultation. Optionee understands that Optionee may suffer
          ----------------
adverse tax consequences as a result of Optionee's purchase or disposition of
the Shares. Optionee represents that Optionee has consulted with any tax
consultants Optionee deems advisable in connection with the purchase or
disposition of the Shares and that Optionee is not relying on the Company for
any tax advice.

     6.   Successors and Assigns. The Company may assign any of its rights under
          ----------------------
this Agreement to single or multiple assignees, and this Agreement shall inure
to the benefit of the successors and assigns of the Company. Subject to the
restrictions on transfer herein set forth, this Agreement shall be binding upon
Optionee and his or her heirs, executors, administrators, successors and
assigns.

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     7.   Interpretation. Any dispute regarding the interpretation of this
          --------------
Agreement shall be submitted by Optionee or by the Company forthwith to the
Administrator which shall review such dispute at its next regular meeting. The
resolution of such a dispute by the Administrator shall be final and binding on
all parties.

     8.   Governing Law; Severability. This Agreement is governed by the
          ---------------------------
internal substantive laws but not the choice of law rules, of Delaware.

     9.   Entire Agreement. The Plan and Option Agreement are incorporated
          ----------------
herein by reference. This Agreement, the Plan, the Option Agreement and the
Investment Representation Statement constitute the entire agreement of the
parties with respect to the subject matter hereof and supersede in their
entirety all prior undertakings and agreements of the Company and Optionee with
respect to the subject matter hereof, and may not be modified adversely to the
Optionee's interest except by means of a writing signed by the Company and
Optionee.

Submitted by:                                Accepted by:

OPTIONEE:                                    NASSDA Corporation


____________________________________         _________________________________
Signature                                    By

____________________________________         _________________________________
Print Name                                   Its

Address:                                     Address:
-------                                      -------

____________________________________         _________________________________
____________________________________         _________________________________


                                             _________________________________
                                             Date Received

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