Note 13 - Stock-based Compensation (Tables)

12 Months Ended

Jan. 02, 2022

Notes Tables

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Fiscal Years
	2021		2020		2019
Cost of revenue	$	282	$	162	$	78
Research and development		843		670		2,242
Selling, general and administrative		1,401		907		824
Total costs and expenses	$	2,526	$	1,739	$	3,144

Share-based Payment Arrangement, Activity [Table Text Block]

	Shares Available for Grant
Balance at December 29, 2019		272
Authorized		550
Options granted		—
Options forfeited or expired		65
RSUs granted		(816	)
RSUs forfeited		249
Balance at January 3, 2021		320
Authorized		600
Options granted		—
Options forfeited or expired		31
RSUs granted		(619	)
RSUs forfeited		262
Balance at January 2, 2022		594

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Term		Aggregate Intrinsic Value
	(in thousands)					(in years)		(in thousands)
Balance outstanding at December 30, 2018		229		$	30.52		3.70
Granted		—			—
Forfeited or expired		(42	)		24.14
Exercised		(1	)		10.92
Balance outstanding at December 29, 2019		186			32.09		3.32
Granted		—			—
Forfeited or expired		(65	)		38.83
Exercised		—			—
Balance outstanding at January 3, 2021		121			28.46		3.75
Granted		—			—
Forfeited or expired		(28	)		31.68
Exercised		—			—
Balance outstanding at January 2, 2022		93		$	27.49		3.19	$	—
Exercisable and Vested and expected to vest at January 2, 2022		93		$	27.49		3.19	$	—

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Options Outstanding		Weighted Average Remaining Contractual Life		Weighted Average Exercise Price		Options Vested and Exercisable		Weighted Average Exercise Price
	(in thousands)		(in years)				(in thousands)
$12.05		48		4.68	$	12.05		48	$	12.05
$30.38		3		0.60		30.38		3		30.38
$31.50		5		0.85		31.5		5		31.50
$32.20		3		1.35		32.2		3		32.20
$40.18		0.4		0.81		40.18		0.4		40.18
$44.80		6		2.96		44.80		6		44.80
$46.62		3		2.35		46.62		3		46.62
$47.46		13		1.94		47.46		13		47.46
$48.72		8		0.35		48.72		8		48.72
$53.48		4		2.38		53.48		4		53.48
$12.05- $53.48		93		3.19	$	27.49		93	$	27.49

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

	RSUs & PRSUs Outstanding
	Number of Shares			Weighted Average Grant Date Fair Value
	(in thousands)
Nonvested at December 30, 2018		183		$	17.22
Granted		353			10.77
Vested		(118	)		14.48
Forfeited		(41	)		—
Nonvested at December 29, 2019		377		$	12.55
Granted		816			3.97
Vested		(144	)		10.41
Forfeited		(249	)		7.93
Nonvested at January 3, 2021		800		$	4.99
Granted		619			5.81
Vested		(586	)		4.99
Forfeited		(265	)		5.00
Nonvested at January 2, 2022		568		$	5.86

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

	Fiscal Years
	2021			2020			2019
Expected life (months)		6.0			6.0			6.0
Risk-free interest rate		0.05	%		0.12	%		2.37	%
Volatility		74	%		82	%		54	%
Dividend yield		—			—			—