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                                                                 Exhibit 4.c.1

                            CONEXANT SYSTEMS, INC.

                       MICROCOSM COMMUNICATIONS LIMITED
                                STOCK OPTION PLAN


                  SECTION 1: PURPOSE

                  In connection with the purchase by Conexant Systems, Inc.
("Conexant") of all the issued and outstanding shares of Microcosm
Communications Limited ("Microcosm") pursuant to the Stock Purchase Agreement,
all Microcosm Options outstanding under the Microcosm Executive Share Option
Scheme will be surrendered and canceled and in exchange, Conexant Options will
be granted. In addition, as additional consideration for the surrender and
cancellation of their Microcosm Options, the holders of Microcosm Options will
be entitled receive additional Conexant Options upon the terms and conditions
set forth in the Stock Purchase Agreement. The purpose of the Plan is to provide
a means for Conexant to perform its obligations under the Stock Purchase
Agreement with respect to the holders of Microcosm Options.



                  SECTION 2:  DEFINITIONS

                  For the purpose of the Plan, the following terms shall have
the meanings set forth below:

                  Acquisition. The purchase by Conexant of all of the issued and
         outstanding ordinary, "A" ordinary and preference shares of Microcosm.

                  Option Agreement. An agreement entered into between Conexant
         and a Participant setting forth the terms and conditions applicable to
         a Conexant Option granted to the Participant.

                  Board of Directors.  The Board of Directors of Conexant.

                  Closing Date. The Closing Date as defined in the Stock
         Purchase Agreement.

                  Conexant.  Conexant Systems, Inc., a Delaware corporation.

                  Conexant Option. An option to purchase Conexant Shares granted
         under the Plan in connection with the Acquisition. All Conexant Options
         issued under
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         the Plan will be Non-qualified stock options, and are not intended to
         comply with the requirements of Section 422 of the Internal Revenue
         Code of 1986, as amended.

                  Conexant Shares. Shares of Common Stock, par value $1 per
         share, of Conexant.

                  Fair Market Value. The closing price of Conexant Stock as
         reported in the NASDAQ reporting system on the relevant date, or if no
         sale of Conexant Shares is reported for such date, the next preceding
         day for which there is a reported sale.

                  Microcosm. Microcosm Communications Limited, a corporation
         incorporated under the laws England and Wales.

                  Microcosm Option. An option to purchase Microcosm Shares
         granted pursuant to the Microcosm Executive Share Option Scheme.

                  Microcosm Shares.  Ordinary shares of Microcosm.

                  Participant. Any person who as at the opening of business on
         the Closing Date held one or more outstanding Microcosm Options and any
         transferee of the Conexant Options granted hereunder.

                  Plan. This Microcosm Communications Limited Stock Option Plan.

                  Securities Act. The Securities Act of 1933, and any successor
         statute, as it may be amended from time to time.

                  Stock Purchase Agreement. The Stock Purchase Agreement dated
         as of January 6, 2000 among Conexant and the Shareholders and Option
         Holders of Microcosm.

                  SECTION 3:  CONEXANT SHARES AVAILABLE UNDER PLAN

                  The total number of Conexant Shares which may be delivered
upon exercise of Conexant Options shall be that number of Conexant Shares as
shall be necessary to provide to the holders of Microcosm Options, in the form
of Conexant Options, their portion of the consideration paid or to be paid by
Conexant pursuant to Sections 2.2(b), 2.3(b), 2.3(d), 2.3(e), 2.4(b) or 2.5(b)
of the Stock Purchase Agreement, as adjusted from time to time as herein
provided. Conexant Shares which may be delivered upon exercise of Conexant
Options may consist in whole or in part of treasury or authorized but unissued
shares, or shares may be acquired, subsequently or in


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anticipation of the transaction, in the open market to satisfy the requirements
of the Plan. Conexant will at all times reserve a sufficient number of
authorized and unissued Conexant Shares to satisfy all outstanding Conexant
Options in full.

                  SECTION 4:  CONEXANT OPTION PROVISIONS

                  a. Option Agreements. Each Conexant Option under the Plan
shall be evidenced by a Stock Option Agreement. Each Stock Option Agreement
shall set forth the number of Conexant Shares subject to the Conexant Option,
which shall be determined in accordance with the provision of Sections 2.2(b),
2.3(b), 2.3(d), 2.3(e), 2.4(b) and 2.5(b) of the Stock Purchase Agreement, and
shall incorporate the Stock Option Terms and Conditions attached as Annex A
hereto. In the event of any conflict between a Stock Option Agreement and the
Plan, the terms of the Plan shall govern.

                  b. Exercising Options. (i) The Conexant Options will be
immediately exercisable and entitle the respective holders thereof to purchase
such number of Conexant Shares at such exercise price as shall be determined
pursuant to the terms of the Stock Purchase Agreement. The exercise price of
such Conexant Options shall be as determined pursuant to the Stock Purchase
Agreement and have been approved by the Chief Executive Officer of Conexant and
may be less than the Fair Market Value on the date of grant (but shall be not
less than $1 per share); provided, however, that the purchase price of the
Conexant Shares with respect to which a Conexant Option or portion thereof is
exercised shall be payable in full in cash or in Conexant Shares, in a
combination of cash and Conexant Shares or a cashless exercise. The value of any
Conexant Share delivered in payment of the exercise price shall be its Fair
Market Value on the date the Conexant Option is exercised. No fractional shares
of stock will be issued or accepted.

                  (ii) From and after the effective date of the resolutions of
the Board of Directors referred to in the immediately following sentence,
Participants may simultaneously exercise such Conexant Options and sell to
Conexant the number of Conexant Shares thereby acquired necessary to make
payment of the exercise price of the Conexant Options and any applicable
personal withholding taxes (a "cashless exercise"). Within 30 days after the
Closing Date, the Conexant Board of Directors will pass a resolution authorizing
the purchase by Conexant of that number of Conexant Shares issued upon exercise
of Conexant Options, at a price per share equal to the Fair Market Value of
Conexant Shares on the day Conexant the Conexant Option is exercised, as is
necessary so that the proceeds of such purchases would be sufficient to pay the
exercise price of the Conexant Options and any applicable personal withholding
taxes in connection with such exercise.


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                  c. Rights as a Shareowner. A Participant shall have no rights
as a shareowner with respect to any shares covered by a Conexant Option until
the date the Participant becomes the holder of record with respect thereof.
Except as provided in Section 7, no adjustment shall be made for dividends or
other rights.

                  d. Withholding. Whenever the exercise of any option, or the
delivery of any Conexant Shares upon exercise of a Conexant Option or transfer
thereof, gives rise to any personal taxes required by law to be withheld from
the Participant, Conexant will have the right as a condition thereto to deduct
from any payment to be made by Conexant or ChaseMellon under the Plan (including
by retaining the notional proceeds received by Conexant on a cashless exercise
of Conexant Options by a sale to Conexant or the cash proceeds received by
ChaseMellon from a cashless exercise of Conexant Options and remitting the cash
or cash equivalent to Microcosm in order for Microcosm to withhold the
applicable personal taxes in connection with such cashless exercise) or to
require the Participant to remit to Conexant an amount sufficient to satisfy
such tax obligation. A Participant may satisfy the withholding obligation by
paying the amount of any taxes in cash or Conexant Shares may be delivered to
Conexant or deducted from the payment or, in accordance with Section 4(b)(ii),
sold to satisfy the obligation in full or in part. If such tax withholding
obligation is paid in Conexant Shares, tax amounts shall be limited to the
statutory minimum as required by law.

                  SECTION 5:  AMENDMENT AND TERMINATION

                  Except as provided in Section 7, (a) the Plan and the Conexant
Options subject thereto may not be amended, suspended or terminated without the
consent in writing of the holders of then outstanding Conexant Options
representing at least 75% of the Conexant Shares underlying such Conexant
Options and (b) without the approval of the shareowners of Conexant, (i) the
number of Shares provided in Section 3 may not be increased and (ii) the
exercise price of any Conexant Option may not be reduced; provided, however,
that no such amendment, suspension or termination shall impair the rights of any
holder of Conexant Options without such holder's consent.

                  SECTION 6:  PLAN ADMINISTRATION

                  The Board of Directors shall exercise all responsibilities,
powers and authority relating to the administration of the Plan.

                  SECTION 7:  ADJUSTMENTS

                  If there shall be any change in or affecting Conexant Shares
on account of any merger, consolidation, reorganization, recapitalization,
reclassification, stock


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dividend, stock split or combination, or other distribution to holders of
Conexant Shares (other than a cash dividend), there shall be made or taken such
amendments to the Plan and such adjustments and actions thereunder as the Board
of Directors may deem appropriate under the circumstances, provided that such
adjustments and actions do not materially adversely affect the Participants or
any holder of Conexant Options granted hereunder, and provided further that in
the event of a recapitalization, reorganization or reclassification of Conexant,
the Conexant Options shall be exercisable for such consideration as that for
which the Conexant Shares are exchanged. Such amendments, adjustments and
actions may include, without limitation, changes in the number of Conexant
Shares which may be issued or transferred pursuant to the Plan, the number of
Conexant Shares subject to outstanding Conexant Options and the related exercise
price per share or a requirement that holders of Conexant Options to exercise
such Conexant Options and become holders of Conexant Shares upon the occurrence
of certain events. Without limiting the generality of the foregoing, (i) if any
such change in or affecting Conexant Shares shall result in an increase in the
number of outstanding Conexant Shares, the number of Conexant Shares remaining
subject to the Plan shall be proportionately increased and the price for each
Conexant Share then covered by an outstanding Conexant Option shall be
proportionately reduced, and (ii) if any such change in or affecting Conexant
Shares shall result in a decrease in the number of outstanding Conexant Shares,
the number of Conexant Shares remaining subject to the Plan shall be
proportionately decreased and the price for each Conexant Share then covered by
an outstanding Conexant Option shall be proportionately increased.

                  SECTION 8:  MISCELLANEOUS

                  a. Until a registration statement registering the Option
Shares has been declared effective by the Securities Exchange Commission, in
connection with the delivery of any Conexant Shares upon exercise of a Conexant
Option, Conexant shall have the right to require as a condition of such delivery
that the recipient represent the following:


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                           (i) that he or she is an accredited investor as such
         term is defined in Rule 501(a) under the Securities Act and is
         acquiring the Conexant Shares issuable upon exercise of the Conexant
         Options for its own account for investment purposes only and not with a
         view to, or for sale or resale in connection with, any public
         distribution thereof or with any present intention of selling,
         distributing or otherwise disposing of any of such shares in violation
         of the Securities Act; or

                           (ii) that he or she is not a U.S. person within the
         meaning of Rule 902(k) of Regulation S under the Securities Act, which
         term includes: (i) a natural person resident in the United States; (ii)
         a partnership or corporation organized or incorporated under the laws
         of the United States; (iii) an estate of which any executor or
         administrator is a U.S. person; (iv) a trust of which any trustee is a
         U.S. person; (v) an agency or branch of a foreign entity located in the
         United States; (vi) a non-discretionary account or similar account
         (other than an estate or trust) held by a dealer or other fiduciary for
         the benefit or account of a U.S. person; (vii) a discretionary account
         or similar account (other than an estate or trust) held by a dealer or
         other fiduciary organized, incorporated or (if an individual) resident
         in the United States; and (viii) a partnership or corporation (A)
         organized or incorporated under the laws of any foreign jurisdiction
         and (B) formed by a U.S. person principally for the purpose of
         investing in securities not registered under the Securities Act, unless
         it is organized or incorporated, and owned, by accredited investors (as
         defined in Rule 501(a) under the Securities Act) who are not natural
         persons, estates or trusts; or

                           (iii) any other matters as Conexant may reasonably
         request of such Conexant Option holder in order to establish to the
         reasonable satisfaction of Conexant that another exemption from the
         registration requirements of the Securities Act is applicable.



                  b. Conexant shall bear all expenses and costs in connection
with the operation of the Plan, including costs related to the purchase, issue
or transfer of Conexant Shares, but excluding personal taxes imposed on any
person receiving a payment or delivery of Shares under the Plan.

                  SECTION 9:  INTERPRETATIONS AND DETERMINATIONS

                  The Board of Directors shall have the power from time to time
to interpret the Plan, to adopt, amend and rescind procedural rules and
regulations relating to the


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exercise of Conexant Options under the Plan, and to take all other actions that
the Board of Directors shall deem necessary or appropriate for the
implementation and administration of the Plan.

                  SECTION 10:  EFFECTIVE DATE

                  The Plan shall become effective as of the Closing Date.

                  SECTION 11:  TERMS OF OPTIONS

                  Each Conexant Option granted under the Plan will be
exercisable for a period of two years from the date of grant.


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