AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 23, 1999
    
 
   
                                                      REGISTRATION NO. 333-69469
    
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                           --------------------------
 
   
                                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                                             93-0835214
          (State or other jurisdiction of                               (I.R.S. Employer
           incorporation or organization)                            Identification Number)

 
                             5555 N.E. MOORE COURT
                          HILLSBORO, OREGON 97124-6421
                                 (503) 681-0118
  (Address, including zip code, and telephone number, including area code, of
                   Registrant's principal executive offices)
                           --------------------------
 
                               STEPHEN A. SKAGGS
                            CHIEF FINANCIAL OFFICER
                       LATTICE SEMICONDUCTOR CORPORATION
                             5555 N.E. MOORE COURT
                          HILLSBORO, OREGON 97124-6421
                                 (503) 681-0118
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                           --------------------------
 
                                    COPY 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:
As soon as practicable after the effective date of this Registration Statement.
                           --------------------------
 
    If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. / /
 
    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. /X/
 
    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. / /
 
    If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. / /
 
    If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. / /
                           --------------------------
 
                        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     REGISTRATION FEE
                                                                                             
Common Stock, $0.01 par value per share,
  upon exercise of warrants to purchase
  shares of Common Stock...................    50,098 shares          $47.875          $2,398,441.75         $666.77(2)

    
 
   
(1) The proposed maximum offering price per share was estimated pursuant to Rule
    457(g) under the Securities Act. Under such Rule, the per share price is
    estimated by reference to the exercise price of the securities, which is
    $47.875.
    
 
   
(2) Registration fee previously paid.
    
                           --------------------------
 
    THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.
 
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

   
THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. WE MAY
NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER
TO SELL THESE SECURITIES AND IT IS NOT SOLICITING AN OFFER TO BUY THESE
SECURITIES IN ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.
    

   
                 SUBJECT TO COMPLETION, DATED FEBRUARY 23, 1999
    
 
                             PRELIMINARY PROSPECTUS
 
   
                                     [LOGO]
 
                                 50,098 SHARES
    
 
                                  COMMON STOCK
 
                                ---------------
 
   
        This prospectus relates to 50,098 shares of common stock of Lattice
    Semiconductor Corporation that are issuable upon exercise of a warrant
    granted to Bain & Company, Inc., the selling stockholder identified in
    this prospectus. The selling stockholder is offering all of the shares
    to be sold in the offering. Lattice will not receive any of the proceeds
    from the offering.
    
 
   
        Lattice's common stock is traded on the Nasdaq National Market under
    the symbol "LSCC."
    
 
                        --------------------------------
 
   
        NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE
    SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR
    DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY
    REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
    
 
                        --------------------------------
 
   
                   The date of this prospectus is
    

                                  THE COMPANY
 
   
    Lattice Semiconductor Corporation was incorporated in Oregon in 1983 and
reincorporated in Delaware in 1985. Its principal executive offices are located
at 5555 N.E. Moore Court, Hillsboro, Oregon 97124-6421, and its telephone number
at that location is (503) 681-0118.
    
 
   
                               SUMMARY OF WARRANT
    
 
   
    This prospectus is part of a registration statement on Form S-3 (file no.
333-69469) and relates to 50,098 shares of Lattice's common stock, $0.01 par
value, that are issuable upon exercise of a warrant granted to Bain & Company,
Inc. The warrant was approved by the Board of Directors of Lattice on May 5,
1998. The initial exercise price for the warrant is $47.875 per share. The
warrant expires on May 5, 2003. For a complete description of the terms of the
warrant, you should read the warrant, which is an exhibit to our registration
statement referenced above.
    
 
   
                                  RISK FACTORS
    
 
   
    AN INVESTMENT IN THE SHARES OF OUR COMMON STOCK OFFERED BY THIS PROSPECTUS
INVOLVES A HIGH DEGREE OF RISK. YOU SHOULD CAREFULLY REVIEW THE FOLLOWING RISK
FACTORS AS WELL AS THE OTHER INFORMATION IN THIS PROSPECTUS BEFORE MAKING AN
INVESTMENT.
    
 
   
    SOME OF THE INFORMATION IN THIS PROSPECTUS CONTAINS FORWARD-LOOKING
STATEMENTS THAT INVOLVE SUBSTANTIAL RISKS AND UNCERTAINTIES. YOU CAN IDENTIFY
THESE STATEMENTS BY FORWARD-LOOKING WORDS SUCH AS "MAY," "WILL," "EXPECT,"
"ANTICIPATE," "BELIEVE," "ESTIMATE" AND "CONTINUE" OR SIMILAR WORDS. YOU SHOULD
READ STATEMENTS THAT CONTAIN THESE WORDS CAREFULLY BECAUSE THEY: (1) DISCUSS OUR
FUTURE EXPECTATIONS; (2) CONTAIN PROJECTIONS OF OUR FUTURE OPERATING RESULTS OR
OF OUR FUTURE FINANCIAL CONDITION; OR (3) STATE OTHER "FORWARD-LOOKING"
INFORMATION. WE BELIEVE IT IS IMPORTANT TO COMMUNICATE OUR EXPECTATIONS TO OUR
INVESTORS. THERE MAY BE EVENTS IN THE FUTURE, HOWEVER, THAT WE ARE NOT
ACCURATELY ABLE TO PREDICT OR OVER WHICH WE HAVE NO CONTROL.
    
 
   
    THE RISK FACTORS LISTED IN THIS SECTION, AS WELL AS ANY CAUTIONARY LANGUAGE
IN THIS PROSPECTUS, PROVIDE EXAMPLES OF RISKS, UNCERTAINTIES AND EVENTS THAT MAY
CAUSE OUR ACTUAL RESULTS TO DIFFER MATERIALLY FROM THE EXPECTATIONS WE DESCRIBE
IN OUR FORWARD-LOOKING STATEMENTS. BEFORE YOU INVEST IN OUR COMMON STOCK, YOU
SHOULD BE AWARE THAT THE OCCURRENCE OF ANY OF THE EVENTS DESCRIBED IN THESE RISK
FACTORS AND ELSEWHERE IN THIS PROSPECTUS COULD HAVE A MATERIAL ADVERSE EFFECT ON
OUR BUSINESS, FINANCIAL CONDITION AND OPERATING RESULTS AND THAT UPON THE
OCCURRENCE OF ANY OF THESE EVENTS, THE TRADING PRICE OF OUR COMMON STOCK COULD
DECLINE AND YOU COULD LOSE ALL OR PART OF YOUR INVESTMENT.
    
 
   
WE DEPEND ON INDEPENDENT ASIAN FOUNDRIES FOR THE SUPPLY AND QUALITY OF OUR
  FINISHED SILICON WAFERS.
    
 
   
    We do not manufacture finished silicon wafers. However, our semiconductor
products require silicon wafers manufactured with state-of-the-art fabrication
equipment and techniques. As a result, our strategy has been to maintain
relationships with large semiconductor foundries for our silicon wafer
production. All our silicon wafers are currently manufactured by either Seiko
Epson in Japan or the UMC Group, a group of affiliated companies in Taiwan. If
Seiko Epson, through its U.S. affiliate Epson Electronics America, or the UMC
Group significantly interrupts our wafer supply, our operating results would be
adversely affected.
    
 
   
    Since worldwide manufacturing capacity for silicon wafers is limited and
inelastic, we could be adversely affected by significant increases in overall
industry wafer demand or interruptions in wafer supply. In the past, we have
experienced delays in obtaining wafers and supply commitments from our
foundries. We negotiate wafer prices and supply commitments on at least an
annual basis with Seiko Epson, Epson Electronics America and the UMC Group. We
currently anticipate that our current supply commitments are adequate through
fiscal 1999. However, existing supply commitments may not be sufficient for us
to satisfy customer demand in future periods. If Seiko Epson, Epson Electronics
America
    
 
                                       2

   
or the UMC Group reduces our supply commitment or increases our wafer prices,
and we cannot find alternative sources of wafer supply, our operating results
could be adversely affected.
    
 
   
    Our two suppliers operate foundries located in Asia. Although we have yet
not experienced significant interruption in supply from our foundries due to
local conditions, the economic, financial, social and political situation in
Asia has recently been volatile. Financial difficulties, new governmental
restrictions, prolonged work stoppages or other difficulties experienced by our
Asian foundries as a result of the specific conditions in Asia may disrupt our
wafer supply and would have an adverse effect on our operating results. Our
wafer purchases from Seiko Epson are denominated in Japanese yen. The value of
the dollar with respect to the yen has fluctuated in the past and may not remain
stable in the future. Future deterioration of dollar-yen exchange rates could
have an adverse effect on our operating results.
    
 
   
    Many of the other factors that could change or disrupt our wafer supply
arrangements are beyond our control. For example, a disruption of Seiko Epson's
or UMC Group's foundry operations as a result of a fire, earthquake or other
natural disaster would disrupt our wafer shipments and would have an adverse
effect on our operating results.
    
 
   
    We also depend on our foundries to produce and deliver silicon wafers with
acceptable yields in a timely manner. Substantially all of our revenues are
derived from semiconductor products based on a specialized silicon wafer
manufacturing process technology called E(2)CMOS-Registered Trademark-. The
manufacture of high performance E(2)CMOS semiconductors is a complicated and
technically demanding process. In order to produce acceptable yields, this
manufacturing process requires:
    
 
   
    - a high degree of technical skill;
    
 
   
    - state-of-the-art equipment;
    
 
   
    - the absence of defects in the masks used to print circuits on a wafer;
    
 
   
    - the elimination of minute impurities and errors in each step of the
      fabrication process; and
    
 
   
    - effective cooperation between the wafer supplier and the circuit designer.
    
 
   
    As is common in our industry, we have experienced yield problems and delays
in the past. If our foundries are unable to produce for a prolonged period
silicon wafers which meet our specifications with acceptable yields, our
operating results could be adversely affected.
    
 
   
    Our future success will depend in part on our ability to maintain and
enhance our wafer manufacturing process technology. We anticipate in the future
migrating to more advanced wafer manufacturing process technologies using larger
wafer sizes and smaller device geometries. We may also utilize additional
foundries. Since we depend upon our foundries to provide their facilities and
support for our process technology development, we may experience delays in the
availability of advanced wafer manufacturing process technologies at existing or
new wafer fabs. As a result, volume production of our
E(2)CMOS-Registered Trademark- process technology at the new fabs of Seiko
Epson, the UMC Group or another foundry may not be achieved. This could have an
adverse effect on our operating results.
    
 
   
OUR FUTURE SUCCESS DEPENDS ON OUR ABILITY TO DEFINE, DEVELOP AND SELL NEW
  PRODUCTS.
    
 
   
    Our future success depends on our ability to introduce new or improved
products that meet the needs of customers in a timely fashion while achieving
acceptable margins. The success of new or improved products depends on a variety
of factors including:
    
 
   
    - product definition;
    
 
   
    - timely and efficient completion of product design;
    
 
   
    - timely and efficient implementation of wafer manufacturing and assembly
      processes;
    
 
                                       3

   
    - product performance;
    
 
   
    - the quality and reliability of the product; and
    
 
   
    - effective sales and marketing.
    
 
   
    Our product development commitments and expenditures must be made well in
advance of product sales. Therefore, the success of new or improved products
depends on our ability to accurately forecast long-term market demand and future
technology developments. Even if we accurately forecast long-term market demand
and future technology developments, competitors may introduce alternative
products that could adversely affect the market acceptance of our new or
improved products. Our future revenue growth depends on the market acceptance of
our new proprietary ISP product families and the continued market acceptance of
our proprietary software development tools. If these product development efforts
are not successful or these products do not achieve market acceptance, our
operating results will be adversely affected.
    
 
   
WE DEPEND ON INDEPENDENT SUBCONTRACTORS, LOCATED PRIMARILY IN ASIA, FOR THE
  ASSEMBLY AND TESTING OF OUR SEMICONDUCTOR PRODUCTS.
    
 
   
    Our finished silicon wafers are assembled and tested by independent
subcontractors located in Hong Kong, Malaysia, the Philippines, South Korea,
Taiwan and the United States. If these independent subcontractors disrupt our
supply of finished product, there could be an adverse effect on our operating
results.
    
 
   
    Most of our assembly and test subcontractors are located in Asia. Although
we have yet not experienced significant interruption in our supply of finished
product from our subcontractors due to local conditions, the economic,
financial, social and political situation in Asia has recently been volatile.
Financial difficulties, new governmental restrictions, prolonged work stoppages
or other difficulties experienced by our Asian subcontractors as a result of the
specific conditions in Asia may disrupt our supply of finished product and could
have an adverse effect on our operating results.
    
 
   
    We also rely on these subcontractors to assemble and test our devices with
acceptable quality and yields. The majority of our revenue is derived from
semiconductor products assembled in advanced packages. The assembly of advanced
packages is a complex process requiring:
    
 
   
    - a high degree of technical skill;
    
 
   
    - state-of-the-art equipment;
    
 
   
    - the absence of defects in lead frames used to attach semiconductor devices
      to the package;
    
 
   
    - the elimination of raw material impurities and errors in each step of the
      process; and
    
 
   
    - effective cooperation between the assembly subcontractor and the device
      manufacturer.
    
 
   
    We have in the past experienced quality and yield problems with our assembly
and test subcontractors. If we experience prolonged problems in the future there
could be an adverse affect on our operating results.
    
 
   
OUR FINANCIAL RESULTS ARE AFFECTED BY THE CYCLICAL NATURE OF THE SEMICONDUCTOR
  INDUSTRY.
    
 
   
    The semiconductor industry is highly cyclical. In the past, the
semiconductor industry has been subject to significant downturns as a result of:
    
 
   
    - diminished demand for semiconductor products;
    
 
   
    - general reductions in semiconductor inventory levels by customers;
    
 
   
    - excess production capacity; and
    
 
                                       4

   
    - accelerated declines in average selling prices.
    
 
   
    If these or other conditions in the semiconductor industry occur in the
future, there could be an adverse effect on our operating results.
    
 
   
OUR QUARTERLY OPERATING RESULTS MAY FLUCTUATE.
    
 
   
    Our quarterly operating results may fluctuate in the future as a result of a
number of factors, including:
    
 
   
    - the cyclical nature of the semiconductor industry;
    
 
   
    - the cyclical nature of demand for our customers' products;
    
 
   
    - general economic conditions in the countries where we sell our products;
    
 
   
    - price competition;
    
 
   
    - the timing of our and our competitors' new product introductions;
    
 
   
    - product obsolescence;
    
 
   
    - the scheduling, rescheduling and cancellation of large orders by our
      customers;
    
 
   
    - our ability to develop new process technologies and achieve volume
      production at the new fabs of Seiko Epson, the UMC Group or another
      foundry;
    
 
   
    - changes in manufacturing yields;
    
 
   
    - adverse movements in exchange rates, interest rates or tax rates; and
    
 
   
    - the availability of adequate supply commitments from our wafer foundries
      and assembly and test subcontractors.
    
 
   
As a result, our past financial results are not necessarily a good predictor of
our future financial results. In the past we have increased our operating
expenses and investment in manufacturing capacity in anticipation of future
revenue growth. If future revenue growth were not to occur in these
circumstances, our operating results would be adversely affected.
    
 
   
OUR STOCK PRICE MAY BE SUBJECT TO SIGNIFICANT VOLATILITY.
    
 
   
    In recent years, the stock market has experienced extreme price volatility
and the price of our common stock has been subject to wide fluctuations. The
overall stock market, the prices of semiconductor stocks in general and the
price of our stock may continue to fluctuate greatly. The price of our stock may
be significantly affected by various factors including:
    
 
   
    - general price fluctuations of the overall stock market and semiconductor
      stocks;
    
 
   
    - quarter to quarter variations in our operating results;
    
 
   
    - shortfalls in revenues or earnings from levels expected by securities
      analysts;
    
 
   
    - announcements of technological innovations or new products by us or our
      competitors; and
    
 
   
    - patent or other proprietary rights developments or litigation.
    
 
   
OUR FINANCIAL RESULTS ARE DEPENDENT ON OUR ABILITY TO COMPETE SUCCESSFULLY IN
  THE HIGHLY COMPETITIVE SEMICONDUCTOR INDUSTRY.
    
 
   
    The semiconductor industry is intensely competitive and is characterized by:
    
 
   
    - rapid technological change;
    
 
                                       5

   
    - sudden price fluctuations;
    
 
   
    - price competition;
    
 
   
    - rapid rates of product obsolescence;
    
 
   
    - periodic shortages of materials and manufacturing capacity;
    
 
   
    - variations in manufacturing costs and yields; and
    
 
   
    - intense competition for sales and distribution channels.
    
 
   
    We compete with major domestic and international semiconductor companies as
well as with emerging companies. We compete directly with companies that have
developed or licensed similar technology and with companies that have licensed
our products and technology. We compete indirectly with a wide variety of
semiconductor companies that offer products and solutions based on alternative
technologies. In addition, we may experience significant competition from
foreign companies in the future. Many of our direct and indirect competitors
have substantially greater financial, technological, manufacturing, marketing
and sales resources than we do. Competition may also increase as the
programmable logic device market expands. If our competitors develop new
products or technologies with better price or performance characteristics, our
operating results could be adversely affected. In addition, if our products
become non-competitive or obsolete due to the introduction of competitive
products, our operating results could be adversely affected.
    
 
   
WE COMPETE WITH OTHER TECHNOLOGY FIRMS TO ATTRACT AND RETAIN KEY TECHNICAL AND
  MANAGEMENT PERSONNEL.
    
 
   
    Our future success depends in part on our ability to attract and retain
highly qualified technical and management personnel, particularly highly skilled
engineers that can develop new products and process technologies. Competition
for technical and management personnel is intense in our industry. We may not be
able to retain our existing key technical and management personnel. In addition,
we may not be able to attract additional qualified employees in the future. If
we lose existing qualified personnel or are unable to hire new qualified
personnel, our product development cycles could be delayed and our operating
results adversely affected.
    
 
   
WE ARE DEPENDENT ON EXPORT SALES FOR A SIGNIFICANT PORTION OF OUR REVENUE.
    
 
   
    Export sales accounted for 50% of our revenues for the first nine months of
fiscal 1999 and 51% of our revenues for the first nine months of fiscal 1998.
Our export sales face unique risks frequently associated with foreign economies
including:
    
 
   
    - changes in local economic conditions;
    
 
   
    - exchange rate volatility;
    
 
   
    - the imposition of governmental controls;
    
 
   
    - export license requirements;
    
 
   
    - restrictions on the export of technology;
    
 
   
    - political instability;
    
 
   
    - trade restrictions;
    
 
   
    - changes in tax laws;
    
 
   
    - changes in tariffs or freight rates;
    
 
   
    - interruptions in air transportation; and
    
 
                                       6

   
    - difficulties in staffing and managing foreign sales offices.
    
 
   
    For example, our export sales have recently been affected by the Asian
economic crisis. Significant changes in the economic climate in the foreign
countries where we derive our export sales could have an adverse effect on our
operating results.
    
 
   
WE MAY BE UNABLE TO ADEQUATELY PROTECT OUR INTELLECTUAL PROPERTY RIGHTS AND MAY
  FACE SIGNIFICANT FUTURE LITIGATION EXPENSES.
    
 
   
    Our success depends in part on our proprietary technology. We intend to
continue to protect our proprietary technology through patents, copyrights and
trade secrets. We believe that our future success will increasingly depend on:
    
 
   
    - technological expertise;
    
 
   
    - continued development of new and improved products; and
    
 
   
    - market acceptance of our new and improved silicon and software products.
    
 
   
However, we may not be able to protect our technology. In addition, our
competitors may develop similar technology independently. We currently have a
number of United States and foreign patents and patent applications. However,
the claims allowed on any of our patents may not be sufficiently broad to
protect our technology. We may also fail to obtain patents from pending and
filed patent applications. Finally, patents issued to us may be challenged,
invalidated or circumvented and any rights allowed under these patents may not
provide any competitive advantage.
    
 
   
    Companies in the semiconductor industry vigorously pursue protection of
their intellectual property rights. Any future protracted litigation we may be
involved in will utilize financial and management resources, which could have an
adverse effect on our operating results. We may also be subject to future
intellectual property claims. If these intellectual property claims were to
occur, we may not be able to obtain a license on favorable terms or without our
operating results being adversely affected.
    
 
   
WE MAY BE UNSUCCESSFUL IN ACHIEVING YEAR 2000 COMPLIANCE IN A TIMELY MANNER.
    
 
   
    Many currently installed computer systems and software products experience
difficulty distinguishing between twenty-first century dates and twentieth
century dates. This is commonly known as the Year 2000 problem.
    
 
   
    We are currently working to address the potential impact of the Year 2000 on
the processing of information by our computerized systems, including interfaces
to our business partners. We have established a project team to manage Year 2000
activities. The project is divided into three phases: assessment, compliance and
testing. We are currently in the compliance phase. We plan to complete our
compliance and testing effort by the third calendar quarter of 1999.
    
 
   
    We do not anticipate that resolution of Year 2000 issues will have a
material adverse impact on our financial position or operating results. As a
result, we have not yet established formal contingency plans. However, if we or
our critical business partners are not successful in addressing Year 2000 issues
on a timely basis, our operating results could be adversely affected. We believe
the most reasonably likely worst case Year 2000 scenario is a temporary
disruption in supplier deliveries or customer shipments. If severe disruptions
in these two areas occur and are not corrected in a timely manner, we may
experience a revenue or profit shortfall in the first half of calendar year
2000.
    
 
                                USE OF PROCEEDS
 
   
    The proceeds received by the Company upon exercise of the warrant will be
used for general working capital purposes.
    
 
                                       7

                          PRICE RANGE OF COMMON STOCK
 
   
    The following table sets forth the range of high and low sale prices of
Lattice's common stock for the indicated periods, as reported by the Nasdaq
National Market. On February 22, 1999, the last reported sale price of the
common stock on the Nasdaq National Market was $49 3/16 per share. As of
February 22, 1999, Lattice had approximately 364 holders of record of the common
stock.
    
 
   


                                                      HIGH        LOW
                                                     -------    -------
                                                          
Fiscal year ended March 29, 1997:
  First Quarter...................................    36 1/4     21 5/8
  Second Quarter..................................    31 1/2     19 3/4
  Third Quarter...................................    47         27 1/2
  Fourth Quarter..................................    54 7/8     39 3/4
 
Fiscal year ended March 28, 1998:
  First Quarter...................................    62 5/8     41 1/2
  Second Quarter..................................    74 1/2     54 7/8
  Third Quarter...................................    67 1/2     45
  Fourth Quarter..................................    57         39 3/4
 
Fiscal year ending April 3, 1999
  First Quarter...................................    54 5/8     25 5/8
  Second Quarter..................................    36 5/8     23 1/4
  Third Quarter...................................   46 1/2      18 7/8
  Fourth Quarter (through February 22, 1999)......   56 5/16    42 7/8

    
 
   
                                DIVIDEND POLICY
    
 
   
    Lattice has never declared or paid cash dividends on its common stock. The
Board of Directors currently intends to retain all earnings for use in Lattice's
business. Therefore, Lattice does not anticipate declaring or paying any cash
dividends on its common stock in the foreseeable future.
    
 
   
                              PLAN OF DISTRIBUTION
    
 
   
    Bain & Company, Inc. (the "selling stockholder") may sell all or a portion
of the shares from time to time on the Nasdaq National Market for its own
accounts at prices prevailing in the public market at the times of such sales.
The selling stockholder may also make private sales directly or through one or
more brokers. These brokers may act as agents or as principals. The selling
stockholder will pay all sales commissions and similar expenses related to the
sale of the shares. Lattice will pay all expenses related to the registration of
the shares.
    
 
   
    The selling stockholder and any broker executing selling orders on behalf of
the selling stockholder may be considered an "underwriter" under the Securities
Act. As a result, commissions received by a broker may be treated as
underwriting commissions under the Securities Act. Any broker-dealer
participating as an agent in that kind of transaction may receive commissions
from the selling stockholder and from any purchaser of shares.
    
 
   
                                 LEGAL MATTERS
    
 
   
    Wilson Sonsini Goodrich & Rosati, Professional Corporation, Palo Alto,
California, has passed upon the validity of the issuance of the common stock
offered by this prospectus for Lattice. Larry W. Sonsini, an officer of Wilson
Sonsini Goodrich & Rosati, Professional Corporation, is a director of Lattice
and owns options to purchase an aggregate of 18,000 shares of Lattice's common
stock and an aggregate of 2,340 shares of Lattice's common stock.
    
 
                                       8

   
                                    EXPERTS
    
 
   
    The consolidated financial statements incorporated in this prospectus by
reference to the Annual Report on Form 10-K of Lattice Semiconductor Corporation
for the year ended March 28, 1998 have been so incorporated in reliance on the
report of PricewaterhouseCoopers LLP, independent accountants, given on the
authority of said firm as experts in auditing and accounting.
    
 
   
                      WHERE YOU CAN FIND MORE INFORMATION
    
 
   
    We file reports, proxy statements and other information with the Commission,
in accordance with the Securities and Exchange Act of 1934. You may read and
copy our reports, proxy statements and other information filed by us at the
public reference facilities of the Commission in Washington, D.C., New York, New
York, and Chicago, Illinois. Please call the Commission at 1-800-SEC-0330 for
further information about the public reference rooms. Our reports, proxy
statements and other information filed with the Commission are available to the
public over the Internet at the Commission's World Wide Web site http://
www.sec.gov.
    
 
   
    The Commission allows us to "incorporate by reference" the information we
filed with them, which means that we can disclose important information by
referring you to those documents. The information incorporated by reference is
considered to be a part of this prospectus, and information that we file later
with the Commission will automatically update and supersede this information. We
incorporate by reference the documents listed below and any future filings made
by us with the Commission under Sections 13(a), 13(c), 14 or 15(d) of the
Exchange Act until our offering is complete:
    
 
   
    - Lattice's Annual Report on Form 10-K for the fiscal year ended March 28,
      1998;
    
 
   
    - Lattice's Quarterly Reports on Form 10-Q for the fiscal quarters ended
      January 2, 1999, September 26, 1998 and June 27, 1998;
    
 
   
    - The description of Lattice's common stock which is contained in Lattice's
      registration statement on Form 8-A filed with the Commission on September
      27, 1989, including any amendment or report filed for the purpose of
      updating any such description; and
    
 
   
    - The description of the preferred stock purchase rights of Lattice
      contained in Lattice's registration statement on Form 8-A filed with the
      Commission on September 13, 1991.
    
 
   
    You may request a copy of these filings, at no cost, by writing or
telephoning us at the following address:
    
 
   
    Chief Financial Officer
    Lattice Semiconductor Corporation
    5555 N.E. Moore Court
    Hillsboro, Oregon 97124-6421
    (503) 681-0118
    
 
   
    You should rely only on the information contained in this document or to
which we have referred you. We have not authorized anyone to provide you with
information that is different. This document may only be used where it is legal
to sell these securities. The information in this document may only be accurate
as of the date on the front of this document.
    
 
                                       9

                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 14.  OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.
 

                                                           
Securities and Exchange Commission registration fee.........  $   666.77
Fees and expenses of counsel................................    8,000.00
Fees and expenses of accountants............................    2,000.00
Blue sky fees and expenses..................................    1,500.00
Miscellaneous...............................................      333.23
                                                              ----------
    Total...................................................  $12,500.00
                                                              ----------
                                                              ----------

 
   
    Except for the Securities and Exchange Commission registration fee, all of
the foregoing expenses have been estimated. All of the above expenses will be
paid by Lattice.
    
 
ITEM 15.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
   
    Lattice's Certificate of Incorporation (the "Certificate") limits, to the
maximum extent permitted by Delaware law, the personal liability of directors
for monetary damages for their conduct as a director. Lattice's Bylaws provide
that Lattice shall indemnify its officers and directors and may indemnify its
employees and other agents to the fullest extent permitted by law.
    
 
    Section 145 of the Delaware General Corporation Law ("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 Certificate 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 Exchange Act of 1934, as amended (the "Exchange Act"), may
be permitted to foregoing provisions and agreements, the Registrant has been
informed that in the opinion of the staff of the Commission such indemnification
is against public policy as expressed in the Exchange Act and is therefore
unenforceable.
 
                                      II-1

ITEM 16.  EXHIBITS.
 
   


  EXHIBIT
  NUMBER                                              DESCRIPTION
- -----------  ----------------------------------------------------------------------------------------------
          
       4.1   Form of Warrant to Purchase Shares of Common Stock dated May 5, 1998.*
 
       5.1   Opinion of Wilson Sonsini Goodrich & Rosati, Professional Corporation, Counsel to the
               Registrant.*
 
      23.1   Consent of PricewaterhouseCoopers LLP, Independent Accountants.
 
      23.2   Consent of Wilson Sonsini Goodrich & Rosati, Professional Corporation, Counsel to the
               Registrant (included in Exhibit 5.1).*
 
      24.1   Power of Attorney (see page II-3 of the initial filing of this Form S-3).*

    
 
- ------------------------
 
   
*   Previously filed.
    
 
ITEM 17.  UNDERTAKINGS.
 
    (a) The 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.
 
    (b) The Registrant hereby undertakes 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.
 
    (c) 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 Commission such indemnification is
against public policy as expressed in the Securities 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 Securities 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-3 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 February 23, 1999.
    
 

                               
                                LATTICE SEMICONDUCTOR CORPORATION
 
                                By:              /s/ CYRUS Y. TSUI
                                     -----------------------------------------
                                                   Cyrus Y. Tsui
                                         PRESIDENT, CHIEF EXECUTIVE OFFICER
                                             AND CHAIRMAN OF THE BOARD

 
   
    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
- -------------------------  -------------------------------  -------------------
 
                                                      
                           President, Chief Executive
    /s/ CYRUS Y. TSUI        Officer (Principal Executive
- -------------------------    Officer) and Chairman of the    February 23, 1999
      Cyrus Y. Tsui          Board of Directors
 
                           Senior Vice President, Chief
  /s/ STEPHEN A. SKAGGS      Financial Officer (Principal
- -------------------------    Financial Officer) and          February 23, 1999
    Stephen A. Skaggs        Secretary
 
            *
- -------------------------  Director                          February 23, 1999
    Mark O. Hatfield
 
            *
- -------------------------  Director                          February 23, 1999
     Daniel S. Hauer
 
            *
- -------------------------  Director                          February 23, 1999
     Harry A. Merlo
 
            *
- -------------------------  Director                          February 23, 1999
    Larry W. Sonsini
 
            *
- -------------------------  Director                          February 23, 1999
    Douglas C. Strain

    
 
   

                                                    
*By:  /s/ STEPHEN A. SKAGGS
      -------------------------
      Stephen A. Skaggs,
      ATTORNEY-IN-FACT

    
 
                                      II-3

                       LATTICE SEMICONDUCTOR CORPORATION
                       REGISTRATION STATEMENT ON FORM S-3
                               INDEX TO EXHIBITS
 
   


  EXHIBIT
  NUMBER                                                   DESCRIPTION
- -----------  --------------------------------------------------------------------------------------------------------
          
       4.1   Form of Warrant to Purchase Shares of Common Stock dated May 5, 1998.*
 
       5.1   Opinion of Wilson Sonsini Goodrich & Rosati, Professional Corporation, Counsel to the Registrant.*
 
      23.1   Consent of PricewaterhouseCoopers LLP, Independent Accountants.
 
      23.2   Consent of Wilson Sonsini Goodrich & Rosati, Professional Corporation, Counsel to the Registrant
               (included in Exhibit 5.1).*
 
      24.1   Power of Attorney (see page II-3 of the initial filing of this Form S-3).*

    
 
- ------------------------
 
   
*   Previously filed.