CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
	Jun. 30, 2012	Jul. 02, 2011
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 597,000	$ 1,669,000
Non-cash adjustments to net income:
Depreciation and amortization	358,000	498,000
Provision for doubtful accounts and sales returns	130,000	51,000
Provision for excess and obsolete inventories	156,000	958,000
Deferred income taxes	(127,000)	(13,000)
Stock-based compensation	745,000	593,000
Tax benefit related to stock-based compensation plans	7,000
Unrealized loss (gain) from short-term investments, categorized as trading	97,000	(99,000)
Amortization of premium on short-term investments	597,000	946,000
Changes in operating assets and liabilities:
Trade accounts receivable	137,000	(927,000)
Inventories	1,358,000	73,000
Prepaid expenses and other assets	(92,000)	451,000
Prepaid income taxes	15,000	(152,000)
Trade accounts payable and accrued expenses	165,000	1,059,000
Deferred revenue	40,000	84,000
Income taxes payable	325,000	(1,834,000)
Net cash provided by operating activities	4,508,000	3,357,000
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property, plant and equipment	(43,000)	(408,000)
Purchases of investments	(49,624,000)	(58,787,000)
Sales of investments	6,398,000	24,189,000
Maturities and redemptions of investments	32,117,000	45,558,000
Net cash (used in) provided by investing activities	(11,152,000)	10,552,000
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from exercise of stock options and employee stock purchase plan	312,000	266,000
Stock repurchases	(113,000)	(3,179,000)
Net cash provided by (used in) financing activities	199,000	(2,913,000)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(6,445,000)	10,996,000
CASH AND CASH EQUIVALENTS:
Beginning of period	19,860,000	23,962,000
End of period	13,415,000	34,958,000
Supplemental cash flow disclosures:
Income taxes paid, net of refunds	$ 7,000	$ 2,599,000