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TESSERA CONFIDENTIAL

                                                                   EXHIBIT 10.12

                               FIRST ADDENDUM TO
                         LIMITED TCC LICENSE AGREEMENT

     This First Addendum is entered into as of this 17th day of December 1996,
(First Addendum Effective Date) between TESSERA INC., a corporation organized
under the laws of Delaware ("Tessera") and Mitsui High-tec, Inc., a corporation
organized under the laws of Japan ("Licensee") and modifies a the Limited TCC
License Agreement ("Agreement") entered into by and between the parties having
an Effective Date of July 22, 1996, with reference to the following facts:

I.   SUPPLEMENT TO THE AGREEMENT. This First Addendum merely supplements certain
provisions of the Agreement. All provisions, including Definitions, contained
within the Agreement are therefore incorporated herein. In the event any of the
provisions Agreement and this First Addendum conflict, the provisions contained
in this First Addendum shall supersede the conflicting provisions.

II.  TCMT RIGHTS. Licensee may make or have made TCMT provided Licensee complies
with the requirements of Paragraph VIII ("Supplier") of the Agreement where
appropriate. Any use of TCMT by Licensee must be for Licensee's assembly of TCC
and related IC packages only, as defined in the Agreement. Licensee may not sell
or resell TCMT (excess, salvage or otherwise) to any party other than Tessera.
Tessera is not obliged, under the Agreement or this First Addendum, to transfer
TCMT information (including documentation, Technical Information, materials
specifications, or supporting information), whether confidential or not, to
Licensee or any third party supplier of Licensee.

III. TECHNOLOGY TRANSFER FEE. As consideration for the new licenses, rights and
privileges defined in this First Addendum, Licensee shall pay the remaining
balance ([*] US DOLLARS (US$[*])) of the [*] US DOLLAR (US $[*]) Technology
Transfer Fee within thirty (30) days of the First Addendum Effective Date.

IV.  ENTIRE UNDERSTANDING: This First Addendum embodies the entire understanding
between the parties relating to the subject matter hereof, whether written or
oral, and there are no prior representations, warranties or agreements between
the parties not contained in this First Addendum. Any amendment or modification
of any provisions of this First Addendum must be in writing, dated and signed by
both parties hereto.

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


For TESSERA INC.:                  For MITSUI HIGH-TEC, INC.:

By: /s/ JOHN W. SMITH              By: /s/ TOSHIYA MATSUBARA
   -------------------------          ------------------------------
Name:  John W. Smith               Name:  Toshiya Matsubara
Title: President & CEO             Title: Managing Director
Date:  11-14-96                    Date:  12-17-96

* Certain information on this page has been omitted and filed
  separately with the Commission. Confidential treatment has
  been requested with respect to the omitted portions.

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