Note 1 - The Company and Basis of Presentation (Details Textual)													1 Months Ended		12 Months Ended
		Feb. 09, 2022 USD ($) $ / shares shares	Nov. 16, 2021 USD ($)	Sep. 30, 2021 USD ($) shares	Sep. 22, 2021 shares	Dec. 11, 2020	Jun. 22, 2020 USD ($) $ / shares shares	Dec. 06, 2019	Nov. 26, 2019	Nov. 25, 2019	Nov. 06, 2019 USD ($)	Jun. 21, 2019 USD ($) $ / shares shares	Feb. 28, 2022 USD ($) shares	Jul. 21, 2020 USD ($) shares	Jan. 02, 2022 USD ($) $ / shares shares	Jan. 03, 2021 USD ($) $ / shares shares	Dec. 29, 2019 USD ($) shares	Aug. 16, 2021 USD ($)	Dec. 21, 2018 USD ($)	Sep. 28, 2018 USD ($)
Restructuring Costs, Total															$ 0	$ 753,000	$ 0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance															19,605,000	22,748,000
Line of Credit, Current															$ 15,000,000	$ 15,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares															$ 0.001	$ 0.001
Proceeds from Issuance of Common Stock															$ 1,342,000	$ 9,296,000	9,437,000
Payments of Stock Issuance Costs															45,000	1,147,000	1,181,000
Revenue from Contract with Customer, Excluding Assessed Tax, Total	[1]														12,685,000	8,634,000	10,310,000
Contract with Customer, Liability, Current															455,000	52,000
Revenue from Contract with Customer, Valuation Allowances And Reserves, Sales Return															13,000	30,000
Equity Securities without Readily Determinable Fair Value, Amount															300,000	0
Reverse Stock Split Ratio, Authorized									15	5
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio								14
Non-marketable Equity Investment [Member] | Fair Value, Nonrecurring [Member]
Equity Securities without Readily Determinable Fair Value, Amount															300,000
Customized Engineering Services [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total															2,700,000
Engineering Services [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total															1,500,000	300,000	$ 0
Professional Services [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Current, Total															250,000
Contract with Customer, Liability, Current															300,000	0
Cost of Revenue, Total															400,000
Professional Services [Member] | Accounts Receivable [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Current, Total															$ 300,000	$ 0
Intellectual Property [Member]
Finite-Lived Intangible Asset, Useful Life (Year)															5 years
Underwritten Public Offering [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							$ 0.001
Proceeds from Issuance of Common Stock							$ 8,800,000					$ 8,000,000.0		$ 8,100,000
Payments of Stock Issuance Costs							$ 1,100,000
Exercise of Option for Overallotment of Shares by Underwriters [Member]
Proceeds from Issuance of Common Stock														496,000
Payments of Stock Issuance Costs														$ 52,000
Share Subscription Agreement [Member]
Payments of Stock Issuance Costs				$ 45,000
Proceeds from Issuance of Common Stock, Net				$ 1,000,000
Registered Direct Offering [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares													310,000
Proceeds from Issuance of Common Stock													$ 1,500,000
Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares															198,000	2,642,000	1,314,000
Common Stock [Member] | Underwritten Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares							2,500,000					1,300,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							$ 0.001					$ 0.001
Shares Issued, Price Per Share (in dollars per share) | $ / shares							$ 3.50					$ 7.0
Common Stock [Member] | Exercise of Option for Overallotment of Shares by Underwriters [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares							375,000					171,429		141,733
Common Stock [Member] | Share Subscription Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares				73,664	125,000
Common Stock [Member] | Registered Direct Offering [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares		310,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares		$ 0.001
Shares Issued, Price Per Share (in dollars per share) | $ / shares		$ 4.78
Proceeds from Issuance of Common Stock		$ 1,500,000
Heritage Bank of Commerce [Member] | Revolving Credit Facility [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance															$ 19,600,000
Line of Credit, Current															$ 15,000,000.0	$ 15,000,000.0
Line of Credit Facility, Maximum Borrowing Capacity																			$ 15,000,000.0	$ 9,000,000.0
Minimum Cash Required for Covenant Related to Credit Facility											$ 3,000,000.0							$ 3,000,000.0	$ 3,000,000.0
Line of Credit Facility, Expiration Period (Year)						1 year					1 year
Debt Instrument, Interest Rate, Stated Percentage											5.50%
Line of Credit Facility, Commitment Fee Amount			$ 45,000
Debt Instrument, Interest Rate, Effective Percentage															3.75%	3.75%
Heritage Bank of Commerce [Member] | Revolving Credit Facility [Member] | Prime Rate [Member]
Debt Instrument, Basis Spread on Variable Rate						0.50%					0.50%

[1] New products include all products manufactured on 180 nanometer or smaller semiconductor processes, eFPGA IP license, professional services, QuickAI and SensiML AI software as a service (SaaS) revenues. Mature products include all products produced on semiconductor processes larger than 180 nanometers. New product revenues of $7.8 million includes revenues from in eFPGA IP license of $1.1 million and professional engineering services of $1.5 million for fiscal 2021. For fiscal years 2020 and 2019 the Company recognized $0.3 million and $0, respectively, in revenues for professional engineering services. Related to the Company's professional services revenue, the Company had Contract assets of approximately $250 thousand included in accounts receivable on its Consolidated Balance Sheet at January 2, 2022 and none at January 3, 2021. Additionally, at January 2, 2022, the Company had contract liabilities, related to its professional services, of $300 thousand included in deferred revenue on its Consolidated Balance Sheet and none at January 3, 2021.