<PAGE>
EXHIBIT 8.1
[LETTERHEAD OF COOLEY GODWARD LLP]
June 1, 2000
Applied Micro Circuits Corporation
6290 Sequence Drive
San Diego, California 92121-4358
Ladies and Gentlemen:
This opinion is being delivered to you in connection with the Form S-4
Registration Statement (the "Registration Statement") filed pursuant to the
Agreement and Plan of Merger and Reorganization dated as of April 18, 2000, (the
"Reorganization Agreement") by and among Applied Micro Circuits Corporation, a
Delaware corporation ("Parent"), OLI Acquisition Corp., Inc., a Delaware
corporation and wholly owned subsidiary of Parent ("Merger Sub"), and
YuniNetworks, Inc., a Delaware corporation (the "Company").
Except as otherwise provided, capitalized terms used but not defined herein
shall have the meanings set forth in the Reorganization Agreement. All section
references, unless otherwise indicated, are to the Internal Revenue Code of
1986, as amended (the "Code").
We have acted as counsel to Parent in connection with the Merger. As such, and
for the purpose of rendering this opinion, we have examined, and are relying
upon (without any independent investigation or review thereof) the truth and
accuracy, at all relevant times, of the statements, covenants, representations
and warranties contained in the following documents (including all exhibits and
schedules attached thereto):
(a) the Reorganization Agreement;
(b) the Registration Statement;
(c) those certain tax representation letters dated June 1, 2000, and
delivered to us by Parent, Merger Sub and the Company containing certain
representations of Parent, Merger Sub and the Company (the "Tax Representation
Letters"); and
(d) such other instruments and documents related to the formation,
organization and operation of Parent, Merger Sub and the Company and related to
the consummation of the Merger and the other transactions contemplated by the
Reorganization Agreement as we have deemed necessary or appropriate.
In connection with rendering this opinion, we have assumed (without any
independent investigation or review thereof) that:
<PAGE>
Applied Micro Circuits Corporation
June 1, 2000
Page Two
(a) Original documents submitted to us (including signatures thereto) are
authentic, documents submitted to us as copies conform to the original
documents, and that all such documents have been (or will be by the Effective
Time) duly and validly executed and delivered where due execution and delivery
are a prerequisite to the effectiveness thereof;
(b) All representations, warranties and statements made or agreed to by
Parent, Merger Sub and the Company, their managements, employees, officers,
directors and stockholders in connection with the Merger, including, but not
limited to, those set forth in the Reorganization Agreement (including the
exhibits thereto) and the Tax Representation Letters are true and accurate at
all relevant times;
(c) All covenants contained in the Reorganization Agreement (including
exhibits thereto) and the Tax Representation Letters are performed without
waiver or breach of any material provision thereof;
(d) The Merger will be reported by Parent and the Company on their
respective federal income tax returns in a manner consistent with the opinion
set forth below;
(e) Any representation or statement made "to the best of knowledge" or
similarly qualified is correct without such qualification; and
(f) The opinion dated June 1, 2000, rendered by Gray Cary Ware &
Freidenrich LLP to the Company pursuant to the Reorganization Agreement has been
delivered and has not been withdrawn.
Based on our examination of the foregoing items and subject to the limitations,
qualifications, assumptions and caveats set forth herein, we are of the opinion
that, for federal income tax purposes, the Merger will be a reorganization
within the meaning of Section 368(a) of the Code.
In addition to your request for our opinion on this specific matter of federal
income tax law, you have asked us to review the discussion of federal income tax
issues contained in the Registration Statement. We have reviewed the discussion
entitled "Material Federal Income Tax Consequences" contained in the
Registration Statement and believe that, insofar as it relates to statements of
law and legal conclusions, it is correct in all material respects.
This opinion does not address the various state, local or foreign tax
consequences that may result from the Merger or the other transactions
contemplated by the Reorganization Agreement. In addition, no opinion is
expressed as to any federal income tax consequence of the Merger or the other
transactions contemplated by the Reorganization Agreement except as specifically
set forth herein, and this opinion may not be relied upon except with respect to
the consequences specifically discussed herein. No opinion is expressed as to
the federal income tax treatment that
<PAGE>
Applied Micro Circuits Corporation
June 1, 2000
Page Three
may be relevant to a particular investor in light of personal circumstances or
to certain types of investors subject to special treatment under the federal
income tax laws (for example, financial institutions, insurance companies,
foreign individuals and entities, tax-exempt entities, dealers in securities,
persons who are subject to the alternative minimum tax provisions of the Code,
persons who acquired their shares of Company capital stock pursuant to the
exercise of an employee option (or otherwise as compensation), persons whose
shares of Company capital stock are qualified small business stock for purposes
of Section 1202 of the Code, or persons who acquired Company capital stock as
part of an integrated investment, such as a "hedge," "straddle," or other risk
reduction transaction, composed of Company capital stock and one or more other
positions).
No opinion is expressed as to any transaction other than the Merger as described
in the Reorganization Agreement, or as to any transaction whatsoever, including
the Merger, if all of the transactions described in the Reorganization Agreement
are not consummated in accordance with the terms of the Reorganization Agreement
and without waiver of any material provision thereof. To the extent that any of
the representations, warranties, statements and assumptions material to our
opinion and upon which we have relied are not accurate and complete in all
material respects at all relevant times, our opinion would be adversely affected
and should not be relied upon.
This opinion only represents our best judgment as to the federal income tax
consequences of the Merger and is not binding on the Internal Revenue Service or
any court of law, tribunal, administrative agency or other governmental body.
The conclusions are based on the Code, existing judicial decisions,
administrative regulations and published rulings. No assurance can be given that
future legislative, judicial or administrative changes or interpretations would
not adversely affect the accuracy of the conclusions stated herein.
Nevertheless, by rendering this opinion, we undertake no responsibility to
advise you of any new developments in the application or interpretation of the
federal income tax laws.
This opinion is being delivered solely in connection with the filing of the
Registration Statement. It is intended for the benefit of Parent and may not be
relied upon or utilized for any other purpose or by any other person and may not
be made available to any other person without our prior written consent.
<PAGE>
Applied Micro Circuits Corporation
June 1, 2000
Page Four
We consent to the reference to our firm under the caption "Material U.S. Federal
Income Tax Consequences" in the Proxy Statement included in the Registration
Statement and to the reproduction and filing of this opinion as an exhibit to
the Registration Statement.
Sincerely,
COOLEY GODWARD LLP
Susan Cooper Philpot
SCP:ls
