EXHIBIT 5.1
 
                        [Graham & James LLP Letterhead]
 
                                January 19, 1999
 
Level One Communications, Incorporated
9750 Goethe Road
Sacramento, California 95827
 
RE: REGISTRATION STATEMENT ON FORM S-3
 
Ladies and Gentlemen:
 
    We have examined the Registration Statement on Form S-3 to be filed by you
with the Securities and Exchange Commission on or about the date hereof (the
"Registration Statement") in connection with the registration under the
Securities Act of 1933, as amended, of up to 2,551,752 shares of your Common
Stock, $.001 par value per share (the "Shares"). All of the Shares are issued
and outstanding and may be offered for sale for the benefit of the selling
stockholders named in the Registration Statement. We understand that the Shares
are to be sold from time to time in the over-the-counter-market at prevailing
prices or as otherwise described in the section entitled "Plan of Distribution"
in the Registration Statement. As your legal counsel, we have also examined the
proceedings taken by you in connection with the issuance of the Shares. We
assume that the consideration received by you in connection with each issuance
of Shares will include an amount in the form of cash, services rendered or
property that exceeds the greater of (i) the aggregate par value of such Shares
or (ii) the portion of such consideration determined by the Company's Board of
Directors to be "capital" for purposes of the Delaware General Corporation Law.
 
    It is our opinion that the Shares are validly issued, fully paid and
non-assessable. We consent to the use of this opinion as an exhibit to the
Registration Statement and further consent to the use of our name wherever
appearing in the Registration Statement, including the Prospectus constituting a
part thereof, and any amendments thereto.
 
Very truly yours,
/s/ Graham & James LLP
GRAHAM & JAMES LLP