Note 11 - Stock-based Compensation (Tables)

6 Months Ended

Oct. 02, 2016

Performance-based Restricted Stock Units [Member]

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Expected term of grants (years)	3
Risk-free interest rate	0.76	%
Expected volatility	50	%

Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity [Table Text Block]

	As of		Six Months Ended
	October 2, 2016		October 2, 2016
					Weighted
	Shares of		Shares of		Average
	Common Stock		Common Stock		Price per Share
Authorized to issue		4,500
Reserved for future issuance		1,301
Issued				16	$	6.94

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	Outstanding Options / Quantity			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)		In-the-money Options Vested and Exercisable (in thousands)
Balance at March 27, 2016		7,722,383		$	7.96		4.40	$	87		48
Granted		1,245,100			6.93
Exercised		(1,426,533	)		6.60
Cancelled		(442,205	)		9.17
Forfeited		(678,756	)		7.71
Balance at October 2, 2016		6,419,989			8.00		4.88		11,239		4,715
Vested and expected to vest, October 2, 2016		5,735,193			8.13		4.72		9,531
Vested and exercisable, October 2, 2016		2,921,673		$	8.94		3.54	$	3,126

Schedule of Cash Proceeds Received from Share-based Payment Awards [Table Text Block]

	Three Months Ended				Six Months Ended
	October 2,		September 27,		October 2,		September 27,
	2016		2015		2016		2015
Intrinsic value of options exercised	$	2,196	$	172	$	2,718	$	598

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

	Shares			Weighted Average Grant-Date Fair Value		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Unvested at March 27, 2016		590,833		$	9.39		1.45	$	3,108
Granted		177,800			4.96
Issued and released		(132,196	)		9.06
Forfeited		(206,529	)		9.69
Unvested at October 2, 2016		429,908		$	7.52		1.45	$	4,002
Expected to vest, October 2, 2016		344,706					1.35	$	3,209

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Three Months Ended				Six Months Ended
	October 2,		September 27,		October 2,		September 27,
	2016		2015		2016		2015
Cost of sales	$	301	$	79	$	415	$	159
Research and development		524		98		770		392
Selling, general and administrative		1,579		1,099		2,312		2,448
Total stock-based compensation expense	$	2,404	$	1,276	$	3,497	$	2,999

Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block]

	October 2, 2016
	Amount (in thousands)		Weighted Average Remaining Recognition Period (in years)
Options	$	4,968		2.61
RSUs		1,412		1.66
PRSUs		481		1.93
Total unrecognized stock-based compensation expense	$	6,861