Note 10 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Jun. 30, 2016	Oct. 31, 2015	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Operating Leases, Rent Expense			$ 3.7	$ 4.0	$ 4.4
Purchase Commitment, Remaining Minimum Amount Committed			$ 16.1
Percentage of Royalties			4.50%
Accrued Royalties			$ 1.2
Research and Development [Member]
Proceeds from Grantors			5.2
Cost of Sales [Member]
Direct Operating Cost, Royalty Expense			5.0	$ 4.2	$ 2.5
Licensed Technology from Supplier One [Member]
Long-term Purchase Commitment, Amount		$ 6.1
Remaining Long Term Purchase Commitment Amount			3.0
Licensed Technology from Supplier Two [Member]
Long-term Purchase Commitment, Amount			3.3
Design Tool Licenses from Supplier One [Member]
Long-term Purchase Commitment, Amount	$ 7.8
Remaining Long Term Purchase Commitment Amount			6.5
Design Tool Licenses from Supplier Two [Member]
Long-term Purchase Commitment, Amount			$ 0.8
Primary Facility in Fremont, California [Member]
Lessee Leasing Arrangements, Operating Leases, Term of Contract			6 years 270 days