Summary Of Significant Accounting Policies	6 Months Ended
Jul. 01, 2012
Summary Of Significant Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	NOTE 1. Summary of Significant Accounting Policies Description of business. PMC-Sierra, Inc. (the “Company” or “PMC”) is a semiconductor innovator transforming networks that connect, move and store digital content. Building on a track record of technology leadership, the Company is driving innovation across storage, optical and mobile networks. PMC’s highly integrated solutions increase performance and enable next generation services to accelerate the network transformation. Basis of presentation. The accompanying interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”) and United States Generally Accepted Accounting Principles (“GAAP”). Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules or regulations. These interim condensed consolidated financial statements are unaudited, but reflect all adjustments which are normal and recurring in nature and are, in the opinion of management, necessary to provide a fair statement of results for the interim periods presented. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011. The results of operations for the interim periods are not necessarily indicative of results to be expected in future periods. Fiscal 2012 will consist of 52 weeks and will end on Sunday, December 30, 2012. Fiscal 2011 consisted of 53 weeks and ended on Saturday, December 31, 2011. The second quarter of each of 2012 and 2011 consisted of 13 weeks. Estimates. The preparation of financial statements and related disclosures in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Estimates are used for, but not limited to, stock-based compensation, purchase accounting assumptions including those used to calculate the fair value of intangible assets and goodwill, the valuation of investments, accounting for doubtful accounts, inventory reserves, depreciation and amortization, asset impairments, sales returns, warranty costs, income taxes including uncertain tax positions, restructuring costs, assumptions used to measure the fair value of the debt component of our senior convertible notes, accounting for employee benefit plans, and contingencies. Actual results could differ materially from these estimates. Recent Accounting Pronouncements. In May 2011, the Financial Accounting Standards Board (“FASB”) issued amendments to disclosure requirements for common fair value measurement. These amendments, effective for the interim and annual periods beginning on or after December 15, 2011, provide common definitions of fair value and common fair value measurements and disclosure requirements between U.S. GAAP and International Financial Reporting Standards (“IFRS”). Consequently, the amendments change some fair value measurement principles and disclosure requirements. The Company adopted this amendment effective the first quarter of fiscal 2012. The adoption of this amended accounting guidance did not have a material impact on our consolidated financial statements. In June 2011, the FASB issued amendments to disclosure requirements for the presentation of comprehensive income. This guidance, effective retrospectively for the interim and annual periods beginning on or after December 15, 2011, requires the presentation of total comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The Company adopted this amendment effective the first quarter of fiscal 2012, and presented total comprehensive income, the components of net income, and components of other comprehensive income in two separate but consecutive statements. In September 2011, the FASB issued Accounting Standards Update (“ASU”) 2011-08, Testing Goodwill for Impairment. This ASU provides companies with the option to assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If this qualitative criteria is not met, then performing the two-step impairment test is unnecessary. However, if a company concludes otherwise, then it is required to perform the first step of the two-step quantitative goodwill impairment test. If the carrying value of a reporting unit exceeds its fair value, then a company is required to perform the second step of this test. This guidance is effective for goodwill impairment tests performed for fiscal years beginning after December 15, 2011, with early adoption permitted. The Company adopted this for the 2012 fiscal year. The adoption of this did not have an impact on our consolidated financial statements.

NOTE 1. Summary of Significant Accounting Policies

Description of business. PMC-Sierra, Inc. (the “Company” or “PMC”) is a semiconductor innovator transforming networks that connect, move and store digital content. Building on a track record of technology leadership, the Company is driving innovation across storage, optical and mobile networks. PMC’s highly integrated solutions increase performance and enable next generation services to accelerate the network transformation.

Basis of presentation. The accompanying interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”) and United States Generally Accepted Accounting Principles (“GAAP”). Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules or regulations. These interim condensed consolidated financial statements are unaudited, but reflect all adjustments which are normal and recurring in nature and are, in the opinion of management, necessary to provide a fair statement of results for the interim periods presented. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011. The results of operations for the interim periods are not necessarily indicative of results to be expected in future periods. Fiscal 2012 will consist of 52 weeks and will end on Sunday, December 30, 2012. Fiscal 2011 consisted of 53 weeks and ended on Saturday, December 31, 2011. The second quarter of each of 2012 and 2011 consisted of 13 weeks.

Estimates. The preparation of financial statements and related disclosures in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Estimates are used for, but not limited to, stock-based compensation, purchase accounting assumptions including those used to calculate the fair value of intangible assets and goodwill, the valuation of investments, accounting for doubtful accounts, inventory reserves, depreciation and amortization, asset impairments, sales returns, warranty costs, income taxes including uncertain tax positions, restructuring costs, assumptions used to measure the fair value of the debt component of our senior convertible notes, accounting for employee benefit plans, and contingencies. Actual results could differ materially from these estimates.

Recent Accounting Pronouncements.

In May 2011, the Financial Accounting Standards Board (“FASB”) issued amendments to disclosure requirements for common fair value measurement. These amendments, effective for the interim and annual periods beginning on or after December 15, 2011, provide common definitions of fair value and common fair value measurements and disclosure requirements between U.S. GAAP and International Financial Reporting Standards (“IFRS”). Consequently, the amendments change some fair value measurement principles and disclosure requirements. The Company adopted this amendment effective the first quarter of fiscal 2012. The adoption of this amended accounting guidance did not have a material impact on our consolidated financial statements.

In June 2011, the FASB issued amendments to disclosure requirements for the presentation of comprehensive income. This guidance, effective retrospectively for the interim and annual periods beginning on or after December 15, 2011, requires the presentation of total comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The Company adopted this amendment effective the first quarter of fiscal 2012, and presented total comprehensive income, the components of net income, and components of other comprehensive income in two separate but consecutive statements.

In September 2011, the FASB issued Accounting Standards Update (“ASU”) 2011-08, Testing Goodwill for Impairment. This ASU provides companies with the option to assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If this qualitative criteria is not met, then performing the two-step impairment test is unnecessary. However, if a company concludes otherwise, then it is required to perform the first step of the two-step quantitative goodwill impairment test. If the carrying value of a reporting unit exceeds its fair value, then a company is required to perform the second step of this test. This guidance is effective for goodwill impairment tests performed for fiscal years beginning after December 15, 2011, with early adoption permitted. The Company adopted this for the 2012 fiscal year. The adoption of this did not have an impact on our consolidated financial statements.