<PAGE>
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON NOVEMBER 7, 1996
 
                                                     REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
 
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                    FORM S-8
 
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                             ---------------------
 
                       LATTICE SEMICONDUCTOR CORPORATION
 
             (Exact name of registrant as specified in its charter)
 
<TABLE>
<S>                    <C>
      DELAWARE              93-0835214
      (State of          (I.R.S. Employer
   Incorporation)       Identification No.)
</TABLE>
 
                             5555 N.E. MOORE COURT
                          HILLSBORO, OREGON 97124-6421
          (Address of Principal Executive Offices, including Zip Code)
 
                            ------------------------
 
                           1996 STOCK INCENTIVE PLAN
                           (Full title of the plans)
 
                            ------------------------
 
                                RODNEY F. SLOSS
                            VICE PRESIDENT, FINANCE
                       LATTICE SEMICONDUCTOR CORPORATION
                             5555 N.E. MOORE COURT
                          HILLSBORO, OREGON 97124-6421
                                 (503) 681-0118
           (Name, address and telephone number of agent for service)
                            ------------------------
 
                                    COPY TO:
 
                               JOHN A. FORE, ESQ.
                        WILSON SONSINI GOODRICH & ROSATI
                            Professional Corporation
                               650 Page Mill Road
                          Palo Alto, California 94304
                                 (415) 493-9300
                            ------------------------
 
                        CALCULATION OF REGISTRATION FEE
 
<TABLE>
<CAPTION>
                                         PROPOSED MAXIMUM   PROPOSED MAXIMUM
TITLE OF SECURITIES       AMOUNT TO       OFFERING PRICE        AGGREGATE          AMOUNT OF
  TO BE REGISTERED      BE REGISTERED      PER SHARE(1)     OFFERING PRICE(1)  REGISTRATION FEE
<S>                   <C>                <C>                <C>                <C>
Common Stock, $0.01
  par value per
  share.............      2,000,000           $34.31         $68,620,000.00       $20,793.94
</TABLE>
 
(1) The Proposed Maximum Offering Price Per Share was estimated in accordance
    with Rule 457 under the Securities Act of 1933, as amended (the "Securities
    Act"), solely for the purpose of computing the amount of the registration
    fee based on the average of the high and low prices of the Company's Common
    Stock as reported by the Nasdaq National Market on October 31, 1996.
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>
                       REGISTRATION STATEMENT ON FORM S-8
 
                                    PART II
 
                 INFORMATION REQUIRED IN REGISTRATION STATEMENT
 
ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.
 
    The following documents and information previously filed with the Securities
and Exchange Commission (the "Commission") by Lattice Semiconductor Corporation
(the "Company") are hereby incorporated by reference in this Registration
Statement:
 
    (a) The Company's Quarterly Report on Form 10-Q for the fiscal quarter ended
June 29, 1996, filed pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934, as amended (the "Exchange Act").
 
    (b) The Company's Annual Report on Form 10-K for the fiscal year ended March
30, 1996, filed pursuant to Section 13(a) or 15(d) of the Exchange Act.
 
    (c) The description of the Company's common stock which is contained in the
Company's Registration Statement on Form 8-A filed with the Commission on
September 27, 1989 pursuant to Section 12 of the Exchange Act, including any
amendment or report filed for the purpose of updating any such description.
 
    All documents subsequently filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a post-effective
amendment which indicates that all securities registered have been sold or which
deregisters all securities then remaining unsold, shall be deemed to be
incorporated by reference in this Registration Statement and to be part hereof
from the date of filing of such documents.
 
ITEM 4. DESCRIPTION OF SECURITIES.
 
    Not applicable.
 
ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.
 
    Not Applicable.
 
ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
    The Company's Restated Certificate of Incorporation, as amended, limits the
personal liability of directors for monetary damages for their conduct as a
director. The Company's Bylaws provide that the Company shall indemnify its
officers and directors and may indemnify its employees and other agents to the
fullest extent permitted by the Delaware General Corporation Law ("Delaware
Law").
 
    Section 145 of the Delaware Law provides that a corporation may indemnify a
director, officer, employee or agent made a party to an action by reason of the
fact that he was a director, officer, employee or agent of the corporation or
was serving at the request of the corporation against expenses actually and
reasonably incurred by him in connection with such action if he acted in good
faith and in a manner he reasonably believed to be in, or not opposed to, the
best interests of the corporation and with respect to any criminal action, had
no reasonable cause to believe his conduct was unlawful.
 
    Delaware Law does not permit a corporation to eliminate a director's duty of
care, and the provisions of the Company's Restated Certificate of Incorporation
have no effect on the availability of equitable remedies such as injunction or
rescission, based upon a director's breach of the duty of care. Insofar as
indemnification for liabilities arising under the Securities Act, may be
permitted to directors, officers or
 
                                      II-1
<PAGE>
persons controlling the Company pursuant to the foregoing provisions, the
Company has been informed that in the opinion of the staff of the Commission
such indemnification is against public policy as expressed in the Securities Act
and is therefore unenforceable.
 
ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.
 
    Not applicable.
 
ITEM 8. EXHIBITS.
 
<TABLE>
<CAPTION>
 EXHIBIT
 NUMBER    DESCRIPTION
---------  --------------------------------------------------------------------------------------------------
<C>        <S>
   4.1     1996 Stock Incentive Plan.
 
   5.1     Opinion of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant.
 
  23.1     Consent of Price Waterhouse, LLP, Independent Accountants.
 
  23.2     Consent of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant (see Exhibit 5.1).
 
  24.1     Power of Attorney (see page II-5).
</TABLE>
 
ITEM 9. UNDERTAKINGS.
 
    The undersigned Registrant hereby undertakes:
 
        (1) To file, during any period in which offers or sales are being made,
    a post-effective amendment to this Registration Statement to include any
    material information with respect to the plan of distribution not previously
    disclosed in the Registration Statement or any material change to such
    information in the Registration Statement.
 
        (2) That, for the purpose of determining any liability under the
    Securities Act, each such post-effective amendment shall be deemed to be a
    new registration statement relating to the securities offered therein, and
    the offering of such securities at that time shall be deemed to be the
    initial bona fide offering thereof.
 
        (3) To remove from registration by means of a post-effective amendment
    any of the securities being registered which remain unsold at the
    termination of the offering.
 
        (4) That, for purposes of determining any liability under the Securities
    Act, each filing of the Registrant's annual report pursuant to Section 13(a)
    or Section 15(d) of the Exchange Act (and, where applicable, each filing of
    an employee benefit plan's annual report pursuant to Section 15(d) of the
    Exchange Act) that is incorporated by reference in the Registration
    Statement shall be deemed to be a new registration statement relating to the
    securities offered therein, and the offering of such securities at that time
    shall be deemed to be the initial bona fide offering thereof.
 
        (5) Insofar as indemnification for liabilities arising under the
    Securities Act may be permitted to directors, officers and controlling
    persons of the Registrant pursuant to the foregoing provisions, or
    otherwise, the Registrant has been advised that in the opinion of the
    Securities and Exchange Commission, such indemnification is against public
    policy as expressed in the Exchange Act and is, therefore, unenforceable. In
    the event that a claim for indemnification against such liabilities (other
    than the payment by the registrant of expenses incurred or paid by a
    director, officer or controlling person of the registrant in the successful
    defense of any action, suit or proceeding) is asserted by such director,
    officer or controlling person in connection with the securities being
    registered, the registrant will, unless in the opinion of its counsel the
    matter has been settled by controlling precedent, submit to a court of
    appropriate jurisdiction the question whether such indemnification by it is
    against public policy as expressed in the Exchange Act and will be governed
    by the final adjudication of such issue.
 
                                      II-2
<PAGE>
                                   SIGNATURES
 
    Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Hillsboro, State of Oregon, on this 5th day of
November, 1996.
 
                                LATTICE SEMICONDUCTOR CORPORATION
 
                                By:              /s/ CYRUS Y. TSUI
                                     -----------------------------------------
                                                   Cyrus Y. Tsui
                                         President, Chief Executive Officer
                                             and Chairman of the Board
 
                               POWER OF ATTORNEY
 
    KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below hereby constitutes and appoints Cyrus Y. Tsui and Stephen A. Skaggs, and
each of them acting individually, as his or her attorney-in-fact, each with full
power of substitution, for him or her in any and all capacities, to sign any and
all amendments to this Registration Statement on Form S-8, and to file the same,
with exhibits thereto and other documents in connection therewith, with the
Securities and Exchange Commission, hereby ratifying and confirming all that
each of said attorneys-in-fact, or any substitute, may do or cause to be done by
virtue hereof.
 
    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:
 
          SIGNATURE                       TITLE                    DATE
------------------------------  --------------------------  -------------------
 
      /s/ CYRUS Y. TSUI         President, Chief Executive
------------------------------    Officer (Principal
        Cyrus Y. Tsui             Executive Officer) and       November 5, 1996
                                  Chairman of the Board of
                                  Directors
 
    /s/ STEPHEN A. SKAGGS       Senior Vice President,
------------------------------    Chief Financial Officer
      Stephen A. Skaggs           (Principal Financial         November 5, 1996
                                  Officer) and Secretary
 
     /s/ RODNEY F. SLOSS        Vice President, Finance
------------------------------    (Principal Accounting
       Rodney F. Sloss            Officer) and Assistant       November 5, 1996
                                  Secretary
 
                                      II-3
<PAGE>
 
          SIGNATURE                       TITLE                    DATE
------------------------------  --------------------------  -------------------
 
     /s/ DANIEL S. HAUER
------------------------------           Director              November 5, 1996
       Daniel S. Hauer
 
      /s/ HARRY A. MERLO
------------------------------           Director              November 5, 1996
        Harry A. Merlo
 
     /s/ LARRY W. SONSINI
------------------------------           Director              November 5, 1996
       Larry W. Sonsini
 
    /s/ DOUGLAS C. STRAIN
------------------------------           Director              November 5, 1996
      Douglas C. Strain
 
                                      II-4
<PAGE>
                       LATTICE SEMICONDUCTOR CORPORATION
 
                       REGISTRATION STATEMENT ON FORM S-8
 
                               INDEX TO EXHIBITS
 
<TABLE>
<CAPTION>
 EXHIBIT
 NUMBER    DESCRIPTION
---------  --------------------------------------------------------------------------------------------------------
<C>        <S>
   4.1     1996 Stock Incentive Plan.
 
   5.1     Opinion of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant.
 
  23.1     Consent of Price Waterhouse, LLP, Independent Accountants.
 
  23.2     Consent of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant (see Exhibit 5.1).
 
  24.1     Power of Attorney (see page II-5).
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 14568}]
{"company-data": {"conformed-name": "LATTICE SEMICONDUCTOR CORP", "cik": "0000855658", "assigned-sic": "3674", "irs-number": "930835214", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-15737", "film-number": "96655951"}, "business-address": {"street1": "5555 NE MOORE COURT", "city": "HILLSBORO", "state": "OR", "zip": "97124-6421", "phone": "5036810118"}, "mail-address": {"street1": "5555 NE MOORE COURT", "city": "HILLSBORO", "state": "OR", "zip": "97124"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON NOVEMBER 7, 1996
 
                                                     REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
 
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                    FORM S-8
 
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                             ---------------------
 
                       LATTICE SEMICONDUCTOR CORPORATION
 
             (Exact name of registrant as specified in its charter)
DELAWARE              93-0835214
      (State of          (I.R.S. Employer
   Incorporation)       Identification No.)
5555 N.E. MOORE COURT
                          HILLSBORO, OREGON 97124-6421
          (Address of Principal Executive Offices, including Zip Code)
 
                            ------------------------
 
                           1996 STOCK INCENTIVE PLAN
                           (Full title of the plans)
 
                            ------------------------
 
                                RODNEY F. SLOSS
                            VICE PRESIDENT, FINANCE
                       LATTICE SEMICONDUCTOR CORPORATION
                             5555 N.E. MOORE COURT
                          HILLSBORO, OREGON 97124-6421
                                 (503) 681-0118
           (Name, address and telephone number of agent for service)
                            ------------------------
 
                                    COPY TO:
 
                               JOHN A. FORE, ESQ.
                        WILSON SONSINI GOODRICH & ROSATI
                            Professional Corporation
                               650 Page Mill Road
                          Palo Alto, California 94304
                                 (415) 493-9300
                            ------------------------
 
                        CALCULATION OF REGISTRATION FEE
PROPOSED MAXIMUM   PROPOSED MAXIMUM
TITLE OF SECURITIES       AMOUNT TO       OFFERING PRICE        AGGREGATE          AMOUNT OF
  TO BE REGISTERED      BE REGISTERED      PER SHARE(1)     OFFERING PRICE(1)  REGISTRATION FEE
Common Stock, $0.01
  par value per
  share.............      2,000,000           $34.31         $68,620,000.00       $20,793.94
(1) The Proposed Maximum Offering Price Per Share was estimated in accordance
    with Rule 457 under the Securities Act of 1933, as amended (the "Securities
    Act"), solely for the purpose of computing the amount of the registration
    fee based on the average of the high and low prices of the Company's Common
    Stock as reported by the Nasdaq National Market on October 31, 1996.
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
REGISTRATION STATEMENT ON FORM S-8
 
                                    PART II
 
                 INFORMATION REQUIRED IN REGISTRATION STATEMENT
 
ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.
 
    The following documents and information previously filed with the Securities
and Exchange Commission (the "Commission") by Lattice Semiconductor Corporation
(the "Company") are hereby incorporated by reference in this Registration
Statement:
 
    (a) The Company's Quarterly Report on Form 10-Q for the fiscal quarter ended
June 29, 1996, filed pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934, as amended (the "Exchange Act").
 
    (b) The Company's Annual Report on Form 10-K for the fiscal year ended March
30, 1996, filed pursuant to Section 13(a) or 15(d) of the Exchange Act.
 
    (c) The description of the Company's common stock which is contained in the
Company's Registration Statement on Form 8-A filed with the Commission on
September 27, 1989 pursuant to Section 12 of the Exchange Act, including any
amendment or report filed for the purpose of updating any such description.
 
    All documents subsequently filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a post-effective
amendment which indicates that all securities registered have been sold or which
deregisters all securities then remaining unsold, shall be deemed to be
incorporated by reference in this Registration Statement and to be part hereof
from the date of filing of such documents.
 
ITEM 4. DESCRIPTION OF SECURITIES.
 
    Not applicable.
 
ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.
 
    Not Applicable.
 
ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
    The Company's Restated Certificate of Incorporation, as amended, limits the
personal liability of directors for monetary damages for their conduct as a
director. The Company's Bylaws provide that the Company shall indemnify its
officers and directors and may indemnify its employees and other agents to the
fullest extent permitted by the Delaware General Corporation Law ("Delaware
Law").
 
    Section 145 of the Delaware Law provides that a corporation may indemnify a
director, officer, employee or agent made a party to an action by reason of the
fact that he was a director, officer, employee or agent of the corporation or
was serving at the request of the corporation against expenses actually and
reasonably incurred by him in connection with such action if he acted in good
faith and in a manner he reasonably believed to be in, or not opposed to, the
best interests of the corporation and with respect to any criminal action, had
no reasonable cause to believe his conduct was unlawful.
 
    Delaware Law does not permit a corporation to eliminate a director's duty of
care, and the provisions of the Company's Restated Certificate of Incorporation
have no effect on the availability of equitable remedies such as injunction or
rescission, based upon a director's breach of the duty of care. Insofar as
indemnification for liabilities arising under the Securities Act, may be
permitted to directors, officers or
 
                                      II-1
persons controlling the Company pursuant to the foregoing provisions, the
Company has been informed that in the opinion of the staff of the Commission
such indemnification is against public policy as expressed in the Securities Act
and is therefore unenforceable.
 
ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.
 
    Not applicable.
 
ITEM 8. EXHIBITS.
EXHIBIT
 NUMBER    DESCRIPTION
---------  --------------------------------------------------------------------------------------------------
4.1     1996 Stock Incentive Plan.
 
   5.1     Opinion of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant.
 
  23.1     Consent of Price Waterhouse, LLP, Independent Accountants.
 
  23.2     Consent of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant (see Exhibit 5.1).
 
  24.1     Power of Attorney (see page II-5).
ITEM 9. UNDERTAKINGS.
 
    The undersigned Registrant hereby undertakes:
 
        (1) To file, during any period in which offers or sales are being made,
    a post-effective amendment to this Registration Statement to include any
    material information with respect to the plan of distribution not previously
    disclosed in the Registration Statement or any material change to such
    information in the Registration Statement.
 
        (2) That, for the purpose of determining any liability under the
    Securities Act, each such post-effective amendment shall be deemed to be a
    new registration statement relating to the securities offered therein, and
    the offering of such securities at that time shall be deemed to be the
    initial bona fide offering thereof.
 
        (3) To remove from registration by means of a post-effective amendment
    any of the securities being registered which remain unsold at the
    termination of the offering.
 
        (4) That, for purposes of determining any liability under the Securities
    Act, each filing of the Registrant's annual report pursuant to Section 13(a)
    or Section 15(d) of the Exchange Act (and, where applicable, each filing of
    an employee benefit plan's annual report pursuant to Section 15(d) of the
    Exchange Act) that is incorporated by reference in the Registration
    Statement shall be deemed to be a new registration statement relating to the
    securities offered therein, and the offering of such securities at that time
    shall be deemed to be the initial bona fide offering thereof.
 
        (5) Insofar as indemnification for liabilities arising under the
    Securities Act may be permitted to directors, officers and controlling
    persons of the Registrant pursuant to the foregoing provisions, or
    otherwise, the Registrant has been advised that in the opinion of the
    Securities and Exchange Commission, such indemnification is against public
    policy as expressed in the Exchange Act and is, therefore, unenforceable. In
    the event that a claim for indemnification against such liabilities (other
    than the payment by the registrant of expenses incurred or paid by a
    director, officer or controlling person of the registrant in the successful
    defense of any action, suit or proceeding) is asserted by such director,
    officer or controlling person in connection with the securities being
    registered, the registrant will, unless in the opinion of its counsel the
    matter has been settled by controlling precedent, submit to a court of
    appropriate jurisdiction the question whether such indemnification by it is
    against public policy as expressed in the Exchange Act and will be governed
    by the final adjudication of such issue.
 
                                      II-2
SIGNATURES
 
    Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Hillsboro, State of Oregon, on this 5th day of
November, 1996.
 
                                LATTICE SEMICONDUCTOR CORPORATION
 
                                By:              /s/ CYRUS Y. TSUI
                                     -----------------------------------------
                                                   Cyrus Y. Tsui
                                         President, Chief Executive Officer
                                             and Chairman of the Board
 
                               POWER OF ATTORNEY
 
    KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below hereby constitutes and appoints Cyrus Y. Tsui and Stephen A. Skaggs, and
each of them acting individually, as his or her attorney-in-fact, each with full
power of substitution, for him or her in any and all capacities, to sign any and
all amendments to this Registration Statement on Form S-8, and to file the same,
with exhibits thereto and other documents in connection therewith, with the
Securities and Exchange Commission, hereby ratifying and confirming all that
each of said attorneys-in-fact, or any substitute, may do or cause to be done by
virtue hereof.
 
    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:
 
          SIGNATURE                       TITLE                    DATE
------------------------------  --------------------------  -------------------
 
      /s/ CYRUS Y. TSUI         President, Chief Executive
------------------------------    Officer (Principal
        Cyrus Y. Tsui             Executive Officer) and       November 5, 1996
                                  Chairman of the Board of
                                  Directors
 
    /s/ STEPHEN A. SKAGGS       Senior Vice President,
------------------------------    Chief Financial Officer
      Stephen A. Skaggs           (Principal Financial         November 5, 1996
                                  Officer) and Secretary
 
     /s/ RODNEY F. SLOSS        Vice President, Finance
------------------------------    (Principal Accounting
       Rodney F. Sloss            Officer) and Assistant       November 5, 1996
                                  Secretary
 
                                      II-3
SIGNATURE                       TITLE                    DATE
------------------------------  --------------------------  -------------------
 
     /s/ DANIEL S. HAUER
------------------------------           Director              November 5, 1996
       Daniel S. Hauer
 
      /s/ HARRY A. MERLO
------------------------------           Director              November 5, 1996
        Harry A. Merlo
 
     /s/ LARRY W. SONSINI
------------------------------           Director              November 5, 1996
       Larry W. Sonsini
 
    /s/ DOUGLAS C. STRAIN
------------------------------           Director              November 5, 1996
      Douglas C. Strain
 
                                      II-4
LATTICE SEMICONDUCTOR CORPORATION
 
                       REGISTRATION STATEMENT ON FORM S-8
 
                               INDEX TO EXHIBITS
EXHIBIT
 NUMBER    DESCRIPTION
---------  --------------------------------------------------------------------------------------------------------
4.1     1996 Stock Incentive Plan.
 
   5.1     Opinion of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant.
 
  23.1     Consent of Price Waterhouse, LLP, Independent Accountants.
 
  23.2     Consent of Wilson Sonsini Goodrich & Rosati, Counsel to the Registrant (see Exhibit 5.1).
 
  24.1     Power of Attorney (see page II-5).