Revenues and Concentrations of Risk (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 03, 2019	Aug. 04, 2018	Aug. 03, 2019	Aug. 04, 2018	Feb. 02, 2019
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	$ 5,603	$ 7,073	$ 10,655	$ 12,475
Long-lived tangible assets	522		522		$ 620
Deferred revenue	2,500		2,500		$ 2,200
Revenue recognized	$ 700	$ 900	$ 1,400	$ 1,800
Customer Concentration Risk | Accounts Receivable | Two Licensees
Revenues From External Customers And Long Lived Assets [Line Items]
Concentration risk (as a percent)			21.00%		29.00%
Customer Concentration Risk | Revenues | Two Licensees
Revenues From External Customers And Long Lived Assets [Line Items]
Concentration risk (as a percent)	25.00%		26.00%	20.00%
Customer Concentration Risk | Revenues | Three Licensees
Revenues From External Customers And Long Lived Assets [Line Items]
Concentration risk (as a percent)		45.00%
U.S. and Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	$ 1,380	$ 1,580	$ 2,722	$ 3,403
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	1,102	2,370	1,947	3,222
Middle East, India and Africa
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	678	1,138	1,471	2,181
Asia/Pacific
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	1,550	942	2,943	1,829
Latin America
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	893	$ 1,043	1,572	$ 1,840
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived tangible assets	200		200		$ 200
Non-US
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived tangible assets	$ 300		$ 300		$ 400