CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Dec. 29, 2012	Dec. 31, 2011
CONDENSED CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Net sales	$ 14,373	$ 14,066	$ 46,351	$ 49,084
Cost of sales	7,057	8,708	24,193	26,132
Gross profit	7,316	5,358	22,158	22,952
Research and development	3,440	3,480	10,482	10,514
Selling, general and administrative	3,113	3,269	9,946	9,226
Total operating expenses	6,553	6,749	20,428	19,740
Income (loss) from operations	763	(1,391)	1,730	3,212
Interest income	331	251	957	737
Other income (expense), net	81	533	273	(170)
Income (loss) before provision for income	1,175	(607)	2,960	3,779
(Benefit from) provision for income taxes	(256)	(703)	242	303
Net income	$ 1,431	$ 96	$ 2,718	$ 3,476
Net Income Per Share [Abstract]
Basic	$ 0.12	$ 0.01	$ 0.23	$ 0.28
Diluted	$ 0.12	$ 0.01	$ 0.23	$ 0.28
Shares used in per share computation:
Basic	11,567,000	12,063,000	11,782,000	12,439,000
Diluted	11,568,000	12,066,000	11,783,000	12,450,000
Cash dividends paid per share	$ 1.00		$ 1.00