Note 14 - Information Concerning Product Lines, Geographic Information, Accounts Receivable and Revenue Concentration (Details Textual) - USD ($) $ in Thousands		12 Months Ended
		Jan. 03, 2021	Dec. 29, 2019	Dec. 30, 2018
Revenue from Contract with Customer, Excluding Assessed Tax, Total	[1]	$ 8,634	$ 10,310	$ 12,629
JAPAN
Revenue from Contract with Customer, Excluding Assessed Tax, Total		$ 2,000	$ 1,800	$ 1,600
JAPAN | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Concentration Risk, Percentage		23.00%	17.00%	12.00%
CHINA
Revenue from Contract with Customer, Excluding Assessed Tax, Total			$ 1,100	$ 1,800
CHINA | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Concentration Risk, Percentage			11.00%	15.00%
UNITED STATES
Revenue from Contract with Customer, Excluding Assessed Tax, Total		$ 5,000	$ 4,700	$ 6,400
UNITED STATES | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Concentration Risk, Percentage		58.00%	46.00%	50.00%
Non-US [Member] | Assets, Total [Member] | Geographic Concentration Risk [Member]
Concentration Risk, Percentage		4.00%	7.00%

[1] New products include all products manufactured on 180 nanometer or smaller semiconductor processes, eFPGA IP license, QuickAI and SensiML AI software as a service (SaaS) revenues. Mature products include all products produced on semiconductor processes larger than 180 nanometer.