Note 12 - Segment and Geographical Information - Net Revenue to Each Significant Country Based on the Ship-to Location (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 29, 2017	Jul. 30, 2016
Sales revenue, net	$ 39,508	$ 61,316	$ 79,072	$ 115,091
CHINA
Sales revenue, net	18,665	33,110	40,455	60,567
TAIWAN, PROVINCE OF CHINA
Sales revenue, net	11,806	9,991	18,757	23,955
UNITED STATES
Sales revenue, net	2,132	11,269	7,652	17,858
KOREA, REPUBLIC OF
Sales revenue, net	2,112	1,606	3,787	3,117
THAILAND
Sales revenue, net	998	2,916	1,852	5,737
Rest of the World [Member]
Sales revenue, net	$ 3,795	$ 2,424	$ 6,569	$ 3,857