Guidance is provided only on a non-GAAP basis due to the inherent difficulty of forecasting the timing or amount of certain items that have been excluded from the forward-looking non-GAAP measures, and a reconciliation to the comparable GAAP guidance has not been provided because certain factors that are materially significant to Microsemi's ability to estimate the excluded items are not accessible or estimable on a forward-looking basis.

Additional Information and Where to Find It

This communication does not constitute an offer to buy or solicitation of an offer to sell any securities. This communication relates to a proposal which Microsemi Corporation ("Microsemi") has made for a business combination transaction with PMC-Sierra Inc. ("PMC"). In furtherance of this proposal and subject to future developments, Microsemi (and, if a negotiated transaction is agreed to, PMC) may file one or more registration statements, prospectuses, proxy statements or other documents with the U.S. Securities and Exchange Commission ("SEC"). This communication is not a substitute for any registration statement, prospectus, proxy statement or other document Microsemi and/or PMC may file with the SEC in connection with the proposed transaction. INVESTORS AND SECURITY HOLDERS OF MICROSEMI AND PMC ARE URGED TO READ THE REGISTRATION STATEMENT, PROSPECTUS, PROXY STATEMENT AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE AS THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION. Any definitive proxy statement (if and when available) will be mailed to stockholders of PMC. Investors and security holders will be able to obtain free copies of these documents (if and when available) and other documents filed with the SEC by Microsemi through the web site maintained by the SEC at  http://www.sec.gov.

Certain Information Regarding Participants

Microsemi and certain of its directors and executive officers may be deemed to be participants in any solicitation with respect to the proposed transaction under the rules of the SEC. Security holders may obtain information regarding the names and interests of Microsemi's directors and executive officers Microsemi's Annual Report on Form 10-K for the year ended September 28, 2014, which was filed with the SEC on November 13, 2014, and Microsemi's proxy statement for the 2015 Annual Meeting of Shareholders, which was filed with the SEC on December 19, 2014. These documents can be obtained free of charge from the sources indicated above. Additional information regarding the interests of these participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, will also be included in any proxy statement and other relevant materials to be filed with the SEC if and when they become available.