Note 10 - Information Concerning Product Lines, Geographic Information and Revenue Concentration - Customer and Distributor Concentration (Details) - Customer Concentration Risk [Member]	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 04, 2021	Jun. 28, 2020	Jul. 04, 2021	Jun. 28, 2020	Jan. 03, 2021
Distributor "A" [Member] | Accounts Receivable [Member]
Concentration risk percentage			11.00%
Distributor "A" [Member] | Revenue Benchmark [Member]
Concentration risk percentage	14.00%	25.00%	13.00%	31.00%
Distributor "C" [Member] | Accounts Receivable [Member]
Concentration risk percentage			10.00%
Distributor "C" [Member] | Revenue Benchmark [Member]
Concentration risk percentage			16.00%	17.00%
Distributor "E" [Member] | Accounts Receivable [Member]
Concentration risk percentage			22.00%
Distributor "E" [Member] | Revenue Benchmark [Member]
Concentration risk percentage	29.00%	29.00%	29.00%	21.00%
Customer P [Member] | Accounts Receivable [Member]
Concentration risk percentage					67.00%
Customer "B" [Member] | Revenue Benchmark [Member]
Concentration risk percentage		12.00%		13.00%
Customer Q [Member] | Accounts Receivable [Member]
Concentration risk percentage					10.00%
Customer "E" [Member] | Revenue Benchmark [Member]
Concentration risk percentage	35.00%		20.00%
Distributor "J" [Member] | Accounts Receivable [Member]
Concentration risk percentage			51.00%
Customer "F" [Member] | Revenue Benchmark [Member]
Concentration risk percentage	29.00%	29.00%	29.00%	21.00%
Customer "M" [Member] | Revenue Benchmark [Member]
Concentration risk percentage		12.00%