Condensed Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Mar. 31, 2013	Apr. 01, 2012	Mar. 27, 2011
Cash flows from operating activities:
Net income (loss)	$ 2,882,000	$ (28,056,000)	$ (35,668,000)
Reconciliation of net income (loss) to net cash provided by (used in) operating activities:
Intangible assets impairment and goodwill			7,485,000
Depreciation and amortization	10,809,000	14,898,000	19,414,000
Gain on sale of intangible asset	(223,000)
Stock-based compensation expense	4,788,000	3,750,000	7,381,000
Impairment charges on investments			62,000
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable and accounts receivable, related party	(4,616,000)	1,598,000	4,814,000
Inventories	(930,000)	3,588,000	(6,962,000)
Other current and non-current assets	528,000	683,000	2,756,000
Accounts payable	1,632,000	(971,000)	(1,202,000)
Accrued compensation and related benefits	(513,000)	(2,364,000)	(1,495,000)
Other current liabilities	(5,847,000)	6,836,000	18,000
Deferred income and allowance on sales to distributors and related party distributor	(1,144,000)	(2,294,000)	435,000
Net cash provided by (used in) operating activities	7,366,000	(2,332,000)	(2,962,000)
Cash flows from investing activities:
Purchases of property, plant and equipment and intellectual property, net	(1,385,000)	(2,539,000)	(3,656,000)
Purchases of short-term marketable securities	(200,654,000)	(169,688,000)	(157,609,000)
Proceeds from maturities of short-term marketable securities	48,687,000	63,226,000	74,459,000
Proceeds from sales of short-term marketable securities	148,914,000	105,040,000	82,294,000
Acquisition of Altior Inc.	(750,000)
Other disposal (investment) activities	360,000	384,000	(219,000)
Net cash used in investing activities	(4,828,000)	(3,577,000)	(4,731,000)
Cash flows from financing activities:
Proceeds from issuance of common stock	6,296,000	3,145,000	1,208,000
Repayment of lease financing obligations	(2,830,000)	(3,561,000)	(3,962,000)
Net cash provided by (used) in financing activities	3,466,000	(416,000)	(2,754,000)
Net increase (decrease) in cash and cash equivalents	6,004,000	(6,325,000)	(10,447,000)
Cash and cash equivalents at the beginning of period	8,714,000	15,039,000	25,486,000
Cash and cash equivalents at the end of period	14,718,000	8,714,000	15,039,000
Supplemental disclosure of non-cash investing and financing activities:
Return of Hillview Facility to Lessor		12,167,000
Issuance of common stock in connection with acquisition	3,740,000	24,000	27,000
Cash paid for income taxes	154,000	122,000	179,000
Cash received from income taxes refund		19,000	3,078,000
Cash paid for interest	165,000	193,000	1,289,000
Property, plant and equipment acquired under capital lease		8,478,000	1,808,000
Hifn [Member]
Supplemental disclosure of non-cash investing and financing activities:
Issuance of common stock in connection with acquisition	19,000	24,000	27,000
Altior [Member]
Supplemental disclosure of non-cash investing and financing activities:
Issuance of common stock in connection with acquisition	$ 3,740,000