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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000855658-07-000002.txt : 20070208
<SEC-HEADER>0000855658-07-000002.hdr.sgml : 20070208
<ACCEPTANCE-DATETIME>20070208165501
ACCESSION NUMBER:		0000855658-07-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070206
FILED AS OF DATE:		20070208
DATE AS OF CHANGE:		20070208

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LATTICE SEMICONDUCTOR CORP
		CENTRAL INDEX KEY:			0000855658
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				930835214
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0101

	BUSINESS ADDRESS:	
		STREET 1:		5555 NE MOORE COURT
		CITY:			HILLSBORO
		STATE:			OR
		ZIP:			97124-6421
		BUSINESS PHONE:		5032688000

	MAIL ADDRESS:	
		STREET 1:		5555 NE MOORE COURT
		CITY:			HILLSBORO
		STATE:			OR
		ZIP:			97124

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DONOVAN STEPHEN M
		CENTRAL INDEX KEY:			0001224170

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18032
		FILM NUMBER:		07593301

	MAIL ADDRESS:	
		STREET 1:		5555 NE MOORE CT.
		CITY:			HILLSBORO
		STATE:			OR
		ZIP:			97124
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-02-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000855658</issuerCik>
        <issuerName>LATTICE SEMICONDUCTOR CORP</issuerName>
        <issuerTradingSymbol>LSCC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001224170</rptOwnerCik>
            <rptOwnerName>DONOVAN STEPHEN M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5555 NE MOORE CT.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HILLSBORO</rptOwnerCity>
            <rptOwnerState>OR</rptOwnerState>
            <rptOwnerZipCode>97124</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Corporate VP, Sales</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Option to Buy</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.05</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>51750</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-05-06</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-02-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>51750</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>712873</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit (RSU)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4415</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4415</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4415</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This option to purchase shares of common stock vests as follows: 6.25% of the total amount of shares subject to the option shall vest on 5/6/07.  6.25% of the total amount of the shares subject to the option shall vest each three months thereafter until all shares are vested on 2/6/11.</footnote>
        <footnote id="F2">Each Restricted Stock Unit (RSU) represents a right to receive one share of the Issuers common shares without payment of specific consideration.</footnote>
        <footnote id="F3">Grants vest upon satisfaction of both of these conditions:
(1) 25% of the RSUs vest on the first anniversary of the date of grant, and an additional 25% of the RSUs vest on each anniversary thereafter; and
(2) 25% of the RSUs vest if the price of a share of common stock on each anniversary of the date of grant has increased at least 15%, compounded annually, over the price on the date of grant, as calculated based on a 60-calendar-day average of NASDAQ closing prices of the Companys stock.  If this condition is not met for any portion of the RSUs on the relevant anniversary date, then such RSUs may vest on any of the three subsequent anniversaries if the price on such date equals or exceeds the required price.  If this condition has not been met for any portion of the RSUs by the third subsequent anniversary of the relevant anniversary date, then such portion of the RSUs shall be forfeited.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Martin R. Baker, Attorney-In-Fact for Stephen M. Donovan</signatureName>
        <signatureDate>2007-02-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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