Exhibit 5.1

                                                JMVS/124194.11
                                                Direct Telephone: (441) 298 3240
                                                Direct e-mail: jvirgil@ask.bm



                                                                    30 June 2003

Marvell Technology Group Ltd.
4th Floor, Windsor Place
22 Queen Street
P.O. Box HM 1179
Hamilton HM EX, Bermuda

Dear Sirs:


MARVELL TECHNOLOGY GROUP LTD.

We have acted as attorneys in Bermuda for Marvell Technology Group Ltd., a
Bermuda company (the "Company") in connection with its filing with the United
States Securities and Exchange Commission of a Registration Statement on Form
S-8 (the "Registration Statement") with respect to 321,963 of the Company's
common shares of par value US$0.002 per share issuable pursuant to options
assumed by the Company that were originally granted under the Radlan Computer
Communication Ltd. Key Employee Share Incentive Plan (1998), the Radlan Computer
Communication Ltd. Key Employee Share Incentive Plan (2002) and the Radlan
Computer Communication Ltd. 2003 Stock Option Plan (as amended) (together, the
"Common Shares").

For the purposes of this opinion we have examined and relied upon the documents
listed, and in some cases defined, in the Schedule to this opinion (the
"Documents") together with such other documentation as we have considered
requisite to this opinion.

ASSUMPTIONS

In stating our opinion we have assumed:

a)    the authenticity, accuracy and completeness of all Documents and other
      documentation examined by us submitted to us as originals and the
      conformity to authentic original documents of all Documents and other
      documentation submitted to us as certified, conformed, notarised or
      photostatic copies;

b)    the genuineness of all signatures on the Documents;

c)    that each of the Documents and other such documentation which was received
      by electronic means is complete, intact and in conformity with the
      transmission as sent;

Marvell Technology Group Ltd.                                       30 June 2003
                                      -2-


d)    that there are no provisions of the laws or regulations of any
      jurisdiction other than Bermuda which would have a material effect on any
      of the opinions herein expressed;

e)    that all representations and factual statements appearing in the
      Registration Statement, the Plans and the Resolutions, other than as to
      the laws of Bermuda, are true, accurate and complete in all material
      respects;

f)    that the Resolutions are in full force and effect and have not been
      rescinded, either in whole or in part, and accurately record the
      resolutions passed by the Board of Directors of the Company in meetings
      which were duly convened and at which a duly constituted quorum was
      present and voting throughout and further that there is no matter
      affecting the authority of the Directors to bring about the issue of the
      Common Shares by the Company under the terms of the Plans, not disclosed
      by the Constitutional Documents or the Resolutions, which would have any
      adverse implication in relation to the opinions expressed herein;

g)    that any option award granted under the Plans relevant to this opinion
      (collectively, "Awards") constitute the legal, valid and binding
      obligations of the parties thereto, other than the Company;

h)    that each Director of the Company, when the Board of Directors of the
      Company passed the Board Resolutions, discharged his fiduciary duty owed
      to the Company and acted honestly and in good faith with a view to the
      best interests of the Company;

i)    that the Company has entered into its obligations under the Plans in good
      faith for the purpose of carrying on its business and that, at the time it
      did so, there were reasonable grounds for believing that the transactions
      contemplated in the respective Plan would benefit the Company;

j)    that at the time of issue by the Share Incentive Committee of the Board of
      Directors of Radlan Computer Communications Ltd. (the "Radlan Committee")
      of any Award, such Radlan Committee was duly constituted having the
      necessary powers and authorities to issue Awards pursuant to the Plans;

k)    that at the time of issue by the Stock Option Committee of the Board of
      Directors (the "Committee") of any Common Shares pursuant to any such
      Award, such Committee is a duly constituted committee of the Board of
      Directors of the Company having the necessary powers and authorities to
      issue Common Shares pursuant to the Plans;

l)    that the approval of the issue of any Common Shares under Awards will be
      duly made either at a duly convened and quorate meeting of the Board of
      Directors of the Company, or at a duly convened and quorate meeting of the
      Committee in a manner complying with the terms of the Bye-laws of the
      Company then in force

Marvell Technology Group Ltd.                                       30 June 2003
                                      -3-


      and within the authority then given to the Committee by the Board of
      Directors of the Company;

m)    that when the issue of any Common Shares under the Plans is authorised,
      the issue price will not be less than the par value of the Shares and that
      the Company will have sufficient authorised share capital to effect such
      issue and will continue to hold the necessary consent from the Bermuda
      Monetary Authority for such share issue;

n)    that in any case where Common Shares are issued by the Company pursuant to
      the Plans on the terms of an Award that does not require the allottee to
      pay to the Company a cash subscription price for such Common Shares, the
      Company will receive prior to the allotment of shares a transfer to it of
      assets from the allottee with a fair value at least equivalent to the
      aggregate par value of the Shares issued to him pursuant to that Award;

o)    that when filed with the Securities and Exchange Commission, the
      Registration Statement will not differ in any material respect from the
      draft referred to in paragraph 1 of the Schedule;

p)    that the records which were the subject of the Company Search were
      complete and accurate at the time of such search and disclosed all
      information which is material for the purposes of this opinion and such
      information has not since the date of the Company Search been materially
      altered; and

q)    that the records which were the subject of the Litigation Search were
      complete and accurate at the time of such search and disclosed all
      information which is material for the purposes of this opinion and such
      information has not since the date of the Litigation Search been
      materially altered.

OPINION

Based upon and subject to the foregoing and subject to the reservations set out
below and to any matters not disclosed to us, we are of the opinion that when
issued and allotted by the Board of Directors of the Company or by the Committee
pursuant to Awards and when fully paid for pursuant to and in accordance with
the terms and conditions of the Plans, as contemplated by the Plans, the Common
Shares will be validly issued, fully-paid and non-assessable shares in the
capital of the Company.

RESERVATIONS

We have the following reservations:

(a)   We express no opinion as to any law other than Bermuda law and none of the
      opinions expressed herein relates to compliance with or matters governed
      by the

Marvell Technology Group Ltd.                                       30 June 2003
                                      -4-


      laws of any jurisdiction except Bermuda. This opinion is limited to
      Bermuda law as applied by the courts of Bermuda at the date hereof.

(b)   Any reference in this opinion to Common Shares being "non-assessable"
      shall mean, in relation to fully paid shares of the Company and subject to
      any contrary provision in any agreement in writing between the Company and
      the holder of such Common Shares, that no shareholder shall be bound by an
      alteration to the Memorandum of Association or Bye-laws of the Company
      after the date on which he became a shareholder, if and so far as the
      alteration requires him to take, or subscribe for additional shares, or in
      any way increases his liability to contribute to the share capital of, or
      otherwise to pay money to, the Company.

(c)   Searches of the Register of Companies at the office of the Registrar of
      Companies are not conclusive and it should be noted that the Register of
      Companies does not reveal:

      (i)   details of matters which have been lodged for filing or registration
            which as a matter of general practice of the Registrar of Companies
            would have or should have been disclosed on the public file but have
            not actually been registered or to the extent that they have been
            registered have not been disclosed or do not appear in the public
            records at the date and time the search is concluded; or

      (ii)  details of matters which should have been lodged for registration
            but have not been lodged for registration at the date the search is
            concluded.

(d)   In order to issue this opinion we have carried out the Searches as
      referred to in the Schedule and have not enquired as to whether there has
      been any change since the date of the Searches.

DISCLOSURE

This opinion is addressed to you in connection with the registration of the
Common Shares with the Securities and Exchange Commission. Further, this opinion
speaks as of its date and is strictly limited to the matters stated herein and
we assume no obligation to review or update this opinion if applicable law or
the existing facts or circumstances should change. We hereby consent to the
inclusion of the opinion as an exhibit to the Registration Statement.

This opinion is governed by and is to be construed in accordance with Bermuda
law. It is given on the basis that it will not give rise to any legal
proceedings with respect thereto in any jurisdiction other than Bermuda.

Yours faithfully
/s/ Appleby Spurling & Kempe

Marvell Technology Group Ltd.                                       30 June 2003


                                    SCHEDULE

1.    An electronic copy of the draft of the Registration Statement received on
      30 June 2003 (excluding the exhibits and excluding the documents
      incorporated by reference).

2.    An electronic copy of each of Radlan Computer Communication Ltd. Key
      Employee Share Incentive Plan (1998), the Radlan Computer Communication
      Ltd. Key Employee Share Incentive Plan (2002) and the Radlan Computer
      Communication Ltd. 2003 Stock Option Plan (as amended) (together, the
      "Plans").

3.    Copies of the Minutes of the meetings of the Board of Directors of the
      Company held on 9 January 2003 and 4 February 2003 (the "Resolutions")

4.    The entries and filings shown in respect of the Company on the file of the
      Company maintained in the Register of Companies at the office of the
      Registrar of Companies in Hamilton, Bermuda, as revealed by a search done
      on 30 June 2003 (the "Company Search");

5.    The entries and filings shown in respect of the Company in the Supreme
      Court Causes Book maintained at the Registry of the Supreme Court in
      Hamilton, Bermuda, as revealed by a search done on 30 June 2003 (the
      "Litigation Search");

      (The Company Search and the Litigation Search are collectively referred to
      as the "Searches")

6.    Copies of the Certificate of Incorporation, Memorandum of Association and
      Bye-laws of the Company incorporating all amendments to 21 June 2001
      (collectively referred to as the "Constitutional Documents");

7.    A copy of the permissions dated 31 May 2000 given by the Bermuda Monetary
      Authority under the Exchange Control Act (1972) and related regulations
      for the issue of shares in the capital of the Company.