QuickLinks -- Click here to rapidly navigate through this document

As filed with the Securities and Exchange Commission on February 5, 2004

Registration No. 333-59992



SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


POST-EFFECTIVE AMENDMENT NO. 1
TO
FORM S-3

REGISTRATION STATEMENT
Under
The Securities Act of 1933


LATTICE SEMICONDUCTOR CORPORATION
(Exact name of Registrant as specified in its charter)


Delaware    
(State or other jurisdiction of
incorporation or organization)
      93-0835214
(I.R.S. Employer
Identification Number)
    5555 N.E. Moore Court
Hillsboro, Oregon 97124-6421
(503) 268-8000
   
(Address, including zip code, and telephone number, including area code, of Registrant's principal executive offices)

Stephen A. Skaggs
President
Lattice Semiconductor Corporation
5555 N.E. Moore Court
Hillsboro, Oregon 97124-6421
(503) 268-8000
(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:
John A. Fore, Esq.
Wilson Sonsini Goodrich & Rosati
Professional Corporation
650 Page Mill Road
Palo Alto, CA 94304
(650) 493-9300

Approximate date of commencement of proposed sale to the public: This post-effective amendment deregisters those shares of common stock that remain unsold hereunder as of the effective date hereof.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.    o

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.    o

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box.    o






DEREGISTRATION OF SECURITIES

        On May 2, 2001, Lattice Semiconductor Corporation (the "Company") filed a registration statement on Form S-3 (No. 333-59992) (the "Registration Statement") which registered for resale from time to time 228,973 shares of its common stock issued to former stockholders of Integrated Intellectual Property, Inc. ("I2P"), which was acquired by the Company on March 16, 2001. The Registration Statement was declared effective by the Securities and Exchange Commission (the "Commission") on May 18, 2001.

        Based on the records of the Company's transfer agent, of the 228,973 shares registered under the Registration Statement, the selling stockholders resold an aggregate of 166,794 shares under the Registration Statement or Rule 144 of the Securities Act of 1933, as amended.

        In accordance with the undertaking contained in the Registration Statement pursuant to item 512(a)(3) of Regulation S-K, the Company respectfully requests that the Commission remove from registration a total of 62,179 shares of its common stock that remain unsold under the Registration Statement. The Company is requesting the removal from registration of these shares as its obligation to maintain the effectiveness of the Registration Statement with respect to the shares pursuant to the registration rights agreements between the Company and former stockholders of I2P has expired.

        Accordingly, the Company hereby de-registers 62,179 shares of its common stock registered pursuant to the Registration Statement remaining unsold thereunder.

        [The remainder of this page is intentionally left blank.]



SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Post-Effective Amendment No. 1 to the Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Hillsboro, State of Oregon, on February 5, 2004.

    LATTICE SEMICONDUCTOR CORPORATION

 

 

By:

/s/  
STEPHEN A. SKAGGS      
Stephen A. Skaggs
President and Secretary

        KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Cyrus Y. Tsui and Stephen A. Skaggs, and each of them individually, as his true and lawful attorneys-in-fact and agents with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities to sign the Registration Statement filed herewith and any or all amendments to said Registration Statement (including post-effective amendments and registration statements filed pursuant to Rule 462(b) under the Securities Act of 1933, as amended, and otherwise), and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission granting unto said attorneys-in-fact and agents the full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the foregoing, as full to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them, or his or her substitute, may lawfully do or cause to be done by virtue thereof.

        Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment No. 1 to the Registration Statement has been signed by the following persons in the capacities and on the dates indicated:

Name
  Title
  Date

*

Cyrus Y. Tsui

 

Chief Executive Officer (Principal Executive
Officer) and Chairman of the Board

 

February 5, 2004

/s/  
STEPHEN A. SKAGGS      
Stephen A. Skaggs

 

President and Secretary

 

February 5, 2004

/s/  
JAN JOHANNESSEN      
Jan Johannessen

 

Corporate Vice President, Chief Financial
Officer (Principal Financial and Accounting
Officer) and Assistant Secretary

 

February 5, 2004

*

Mark O. Hatfield

 

Director

 

February 5, 2004

*

Daniel S. Hauer

 

Director

 

February 5, 2004

*

Soo Boon Koh

 

Director

 

February 5, 2004


*

Harry A. Merlo

 

Director

 

February 5, 2004

*

Larry W. Sonsini

 

Director

 

February 5, 2004

*By:

 

/s/  
STEPHEN A. SKAGGS      
Stephen A. Skaggs
Attorney-In-Fact

 

 

 

 



QuickLinks

DEREGISTRATION OF SECURITIES
SIGNATURES