    <SEC-DOCUMENT>0001193125-21-288128-index.html : 20210930
    <SEC-HEADER>0001193125-21-288128.hdr.sgml : 20210930
    <ACCEPTANCE-DATETIME>20210930172541
    ACCESSION NUMBER:		0001193125-21-288128
    CONFORMED SUBMISSION TYPE:	PREM14A
    PUBLIC DOCUMENT COUNT:		7
    CONFORMED PERIOD OF REPORT:	20211123
    FILED AS OF DATE:		20210930
    DATE AS OF CHANGE:		20210930

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			MoSys, Inc.
    		CENTRAL INDEX KEY:			0000890394
    		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
    		IRS NUMBER:				770291941
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		PREM14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-32929
    		FILM NUMBER:		211295940

    	BUSINESS ADDRESS:
    		STREET 1:		2309 BERING DRIVE
    		CITY:			SAN JOSE
    		STATE:			CA
    		ZIP:			95131
    		BUSINESS PHONE:		408 418 7500

    	MAIL ADDRESS:
    		STREET 1:		2309 BERING DRIVE
    		CITY:			SAN JOSE
    		STATE:			CA
    		ZIP:			95131

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	MONOLITHIC SYSTEM TECHNOLOGY INC
    		DATE OF NAME CHANGE:	19960613
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>PREM14A
    <SEQUENCE>1
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    <DESCRIPTION>PREM14A
    <TEXT>
    Document 1 - file: d228931dprem14a.htm

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    <SEQUENCE>2
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: g228931g46a01.jpg

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    <DOCUMENT>
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    <SEQUENCE>3
    <FILENAME>g228931g46a02.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: g228931g46a02.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>g228931g47a01.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: g228931g47a01.jpg

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    <SEQUENCE>5
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: g228931g47a02.jpg

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    <SEQUENCE>6
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: g228931g47a03.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>g228931g47a04.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: g228931g47a04.jpg

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    </SEC-DOCUMENT>