Significant Accounting Policies (Policies)	12 Months Ended
Jan. 02, 2022
Accounting Policies [Abstract]
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash Equivalents and Restricted Cash The Company considers all short-term, highly liquid investments with an original or a remaining maturity at purchase of ninety days or less to be cash equivalents. The Company’s investment portfolio included in cash equivalents is generally comprised of investments that meet high credit quality standards. The Company’s investment portfolio consists of money market accounts and funds. Restricted cash represents amounts pledged as cash security related to the use of credit cards.
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Currency Transactions All of the Company’s sales and cost of manufacturing are transacted in U.S. dollars. Accordingly, all monetary assets and liabilities of these foreign operations are translated into U.S. dollars at current period-end exchange rates and non-monetary assets and related elements of expense are translated using historical exchange rates. Income and expense elements are translated to U.S. dollars using the average exchange rates in effect during the period. Gains and losses from the foreign currency transactions of these subsidiaries are recorded as interest income and other expense, net in the Consolidated Statements of Operations. The Company conducts a portion of its research and development activities in India and has sales and marketing activities in various countries outside of the United States. Most of these international expenses are incurred in local currency. Foreign currency transaction gains and losses, which are not significant, are included in interest income and other expense, net, as they occur. Operating expenses denominated in foreign currencies were approximately 21%, 18%and 19%of total operating expenses in fiscal years 2021, 2020, and 2019 respectively. The Company incurred a majority of these foreign currency expenses in India, the United Kingdom, China, Japan, Taiwan and Korea in fiscal years 2021, 2020, and 2019. The Company has not used derivative financial instruments to hedge its exposure to fluctuations in foreign currency and, therefore, is susceptible to fluctuations in foreign exchange gains or losses in its results of operations in future reporting periods.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is calculated on a straight-line basis over the estimated useful lives of the assets, generally one to seven years. Amortization of leasehold improvements is computed on a straight-line basis over the shorter of the lease term or the estimated useful lives of the assets, generally one to seven years. Capitalized Internal-Use Software The Company capitalizes costs related to development of hosted services that the Company provides to its customers and internal use of enterprise-level business and finance software in support of the Company’s operational needs. Costs incurred in the application development phase are capitalized and amortized on a straight-line basis over their useful lives, which are generally five years. Costs related to planning and other preliminary project activities and post-implementation activities are expensed as incurred. The Company tests these assets for impairment whenever events or changes in circumstances occur that could impact their recoverability. Long-Lived Assets The Company reviews the recoverability of its long-lived assets, such as property and equipment, annually and when events or changes in circumstances occur that indicate that the carrying value of the asset or asset group may not be recoverable. The assessment of possible impairment is based on the Company’s ability to recover the carrying value of the asset or asset group from the expected future pre-tax cash flows, undiscounted and without interest charges, of the related operations, as well as the useful lives applied to the assets. If these cash flows are less than the carrying value of the asset or asset group, an impairment loss is recognized for the difference between the estimated fair value and the carrying value, and the carrying value of the related assets is reduced by this difference. The measurement of impairment requires management to estimate future cash flows and the fair value of long-lived assets. During 2021, 2020 and 2019 the Company recognized losses (gain) on equipment with a net book value of ($5,000), $44,000 and $4,000, respectively. Approximately $35,000 of the equipment written-off during fiscal 2020 was included in Restructuring costs on the Company's Statements of Operations for year ended January 3, 2021.
Accounts Receivable [Policy Text Block]	Accounts Receivable Allowance The Company estimates the amount of uncollectible accounts receivable at the end of each reporting period based on the aging of the receivable balance, current and historical customer trends, and communications with its customers. Amounts are written off only after considerable collection efforts have been made and the amounts are determined to be uncollectible. There were no significant write-off amounts for each of the 2021, 2020, and 2019 fiscal years. At the end of its 2021 and 2020 fiscal years, respectively, the Company had $62,000 and $0 in allowance for bad debts on its Consolidated Balance Sheets.
Standard Product Warranty, Policy [Policy Text Block]	Warranty Costs The Company warrants finished goods against defects in material and workmanship under normal use for twelve months from the date of shipment. The Company’s liability is limited to the cost of repair or replacement of the defective part. The Company does not consider activities related to such warranties to be a separate performance obligation under ASC 606. The terms and conditions of sale generally do not allow for refunds or product returns other than for warranty repairs. The Company does not have significant product warranty related costs or liabilities for fiscal years 2021, 2020, and 2019.
Lessee, Leases [Policy Text Block]	Leases The Company accounts for leases under ASC 842 and related ASUs. Under ASC 842, all significant lease arrangements are generally recognized at lease commencement. Operating lease right-of-use ("ROU"), assets and lease liabilities are recognized at the commencement date. A ROU asset and corresponding lease liability is not recorded for leases with an initial term of 12 months or less (short term leases) and the Company recognizes lease expense for these leases as incurred over the lease term. ROU assets represent the Company’s right to use an underlying asset during the reasonably certain lease terms and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company primarily uses its incremental borrowing rate, based on the information available at commencement date, in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments related to initial direct cost and prepayments and excludes lease incentives. Lease expense is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are generally accounted for separately. In accordance with ASU No. 2016-02, the Company recognized right-of-use assets of approximately $975,000 and lease liabilities of approximately $939,000 on the Company’s Consolidated Balance Sheet as of March 31, 2019, with no material impact to its Consolidated Statements of Operations. In 2020, pursuant its restructuring activities, the Company impaired the remaining right-of-use asset associated with its prior India location amounting to approximately $93,000, which is included with Restructuring costs on the Company's Consolidated Statements of Operations. As of January 2, 2022,the Company’s right-of-use assets were approximately $1.5 million and lease liabilities were approximately $1.6 million as presented on the Company’s Consolidated Balance Sheet. See Note 8.
Business Combinations Policy [Policy Text Block]	Business Combinations The Company recognizes assets acquired (including goodwill and identifiable intangible assets) and liabilities assumed at fair value on the acquisition date. Subsequent changes to the fair value of such assets acquired and liabilities assumed are recognized in earnings, after the expiration of the measurement period, a period not to exceed 12 months from the acquisition date. Acquisition-related expenses and acquisition-related restructuring costs are recognized in earnings in the period in which they are incurred.
Goodwill and Intangible Assets, Policy [Policy Text Block]	Goodwill and Intangible Assets Goodwill represents the excess fair value of consideration transferred over the fair value of net assets acquired in business combinations. The carrying value of goodwill and indefinite lived intangible assets are not amortized but are annually tested for impairment during the Company's fourth fiscal quarter, and more often if there is an indicator of impairment. The Company recognized total goodwill of $185,000 in fiscal 2019 due to tax benefits that arose from intangible assets acquired in the SensiML acquisition including measurement period adjustments, occurring within 12 months from the date of acquisition, and therefore, accounted for under acquisition accounting. The Company's performs its annual goodwill impairment testing during the Company's fourth fiscal quarter. Subsequent to the Company's annual impairment testing in November 2021 and to January 2, 2022, there were no indicators of impairment that gave cause for additional impairment testing of goodwill. No impairment of goodwill has been recognized to date. Intangible assets with finite useful lives are amortized on a straight-line basis over the periods benefited. The Company reviews the recoverability of its long-lived assets when events or changes in circumstances occur that indicate that the carrying value of the asset or asset group may not be recoverable. The assessment of possible impairment is based on the Company's ability to recover the carrying value of the asset or asset group from the expected future pre-tax cash flows (undiscounted and without interest charges) of the related operations. If these cash flows are less than the carrying value of such asset, an impairment loss is recognized for the difference between estimated fair value and carrying value. The measurement of impairment requires management to estimate future cash flows and the fair value of long-lived assets. The Company performed an annual impairment assessment in November 2021 and deemed no impairment was necessary for the current year. No impairment of intangible assets has been recognized to-date.
Advertising Cost [Policy Text Block]	Advertising Costs related to advertising and promotion expenditures are charged to “Selling, general and administrative” expense in the consolidated statements of operations as incurred. Costs related to advertising and promotion expenditures were $47,000 in 2021, $76,000 in 2020, and $146,000 in 2019.
Share-based Payment Arrangement [Policy Text Block]	Stock-Based Compensation The Company accounts for stock-based compensation under the provisions of the amended authoritative guidance, and related interpretations which require the measurement and recognition of expense related to the fair value of stock-based compensation awards. The fair value of stock-based compensation awards is measured at the grant date and re-measured upon modification, as appropriate. The Company uses the Black-Scholes option pricing model to estimate the fair value of employee stock options and rights to purchase shares under the 2019 Stock Plan, and 2009 Stock Plan, 1999 Employee Stock Purchase Plan (" ESPP"), consistent with the provisions of the amended authoritative guidance. The fair value of restricted stock awards ("RSA"), and restricted stock units ("RSU"), is based on the closing price of the Company’s common stock on the date of grant. Using the Black-Scholes pricing model requires us to develop highly subjective assumptions, including the expected term of awards, expected volatility of our stock, expected risk-free interest rate and expected dividend rate over the term of the award. Our expected term of awards is based primarily on our historical experience with similar grants. Our expected stock price volatility for both stock options and ESPP shares is based on the historic volatility of our stock, using the daily average of the opening and closing prices and measured using historical data appropriate for the expected term. The risk-free interest rate assumption approximates the risk-free interest rate of a Treasury Constant Maturity bond with a maturity approximately equal to the expected term of the stock option or ESPP shares. Since we recognize compensation expense only for awards ultimately expected to vest; therefore, we are required to develop an estimate of the historical pre-vest forfeiture experience and apply this to all stock-based awards. The fair value of restricted stock awards, or RSAs, and restricted stock units, or RSUs, is based on the closing price of our common stock on the date of grant. RSA and RSU awards which vest with service are expensed over the requisite service period. RSAs and RSU awards that are expected to vest based on the achievement of a performance goal are expensed over the estimated vesting period, which is estimated by management. We regularly review the assumptions used to compute the fair value of our stock-based awards and we revise our assumptions as appropriate. See Note 13.
Income Tax, Policy [Policy Text Block]	Accounting for Income Taxes As part of the process of preparing our financial statements, we are required to estimate our income taxes in each of the jurisdictions in which we operate. This process involves estimating our actual current tax exposure together with assessing temporary differences resulting from different tax and accounting treatment of items, such as deferred revenue, allowance for doubtful accounts, the impact of equity awards, depreciation and amortization, and employee-related accruals. These differences result in deferred tax assets and liabilities, which are included on our balance sheets. We must then assess the likelihood that our deferred tax assets will be recovered from future taxable income. To the extent we believe that recovery is not likely, we must establish a valuation allowance. To the extent we establish a valuation allowance or increase this allowance in a period, we must include an expense within the tax provision in the statements of operations. Significant management judgment is required in determining our provision for income taxes, deferred tax assets, liabilities and any valuation allowance recorded against our net deferred tax assets. Our deferred tax assets net of deferred tax liabilities relating to an ROU asset of $0.4 million, consisted primarily of net operating loss carryforwards, depreciation and amortization, amounted to approximately $61 million, tax effected, as of the end of 2021 . In evaluating our ability to recover our deferred tax assets within the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, uncertainty of projecting future taxable income and results of recent operations. As of January 2, 2022 , we had federal and state income tax net operating loss, or NOL, carryforwards of approximately $183.9 million and $94.4 million, respectively, which will expire at various dates from 2022 through 2041. Federal net operating losses generated in 2019 and forward of $55.3 million can be carried forward indefinitely. We had research credit carryforwards of approximately $3.7 million for federal and $4.7 million for state income tax purposes as of January 2, 2022 . If not utilized, the federal carryforwards will expire at various dates from 2022. The California credit can be carried forward indefinitely. We believe that it is more likely than not that the deferred tax assets and benefits from these federal and state NOL and credit carryforwards will not be realized. In recognition of this risk, we have recorded a valuation allowance of $60 million, tax-effected, as of the end of 2021 , due to uncertainties related to our ability to utilize our U.S. deferred tax assets before they expire. The Company accounts for uncertainty in income taxes using a two-step approach for recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. The Company classifies the liability for unrecognized tax benefits as current to the extent that it anticipates payment (or receipt) of cash within one year. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes. Accrued interest and penalties are included within the accrued liabilities line in the Consolidated Balance Sheet.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentrations of Credit and Suppliers Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash and cash equivalents and accounts receivable. Cash and cash equivalents are maintained with high quality institutions. The Company’s accounts receivables are denominated in U.S. dollars and are derived primarily from sales to customers located in North America, Europe and Asia Pacific. The Company performs ongoing credit evaluations of its customers and generally does not require collateral. See Note 14 for information regarding concentrations associated with accounts receivable. The Company depends on a limited number of contract manufacturers, subcontractors, and suppliers for wafer fabrication, assembly, programming and test of its devices, and for the supply of programming equipment, and these services are typically provided by one supplier for each of the Company’s devices. The Company generally purchases these single or limited source services through standard purchase orders. Because the Company relies on independent subcontractors to perform these services, it cannot directly control its product delivery schedules, costs or quality levels. The Company’s future success also depends on the financial viability of its independent subcontractors.
Comprehensive Income, Policy [Policy Text Block]	Comprehensive Income (Loss) Comprehensive income (loss) includes all temporary changes in equity (net assets) during a period from non-owner sources. The Company’s comprehensive loss equaled to net loss for all periods presented.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted New Accounting Pronouncements: In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes, which removes certain exceptions to the general principles of ASC 740, in order to reduce the cost and complexity of its application. These changes include elimination to the exceptions for (1) Intra-period tax allocation, (2) Deferred tax liabilities related to outside basis differences, and (3) Year-to-date losses in interim periods. This standard is effective for the fiscal years beginning after December 15, 2020. The Company adopted ASU No. 2019-12, as of January 4, 2021, without significant impact on its Consolidated Financial Statements. New Accounting Pronouncements Pending Adoption In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which address issues identified as a result of the complexity associated with applying generally accepted accounting principles for certain financial instruments with characteristics of liabilities and equity. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Board specified that an entity should adopt the guidance as of the beginning of its annual fiscal year. The Company is in process of assessing the impact of ASU No. 2020-06 on its Consolidated Financial Statements. In May 2021, ASU No. 2021-04, Issuer’s Accounting for Certain Modifications of Exchanges of Freestanding Equity-Classified Written Call Options, was issued to clarify the accounting for modifications or exchanges of freestanding equity-classified written call options, such was warrants, that remain equity classified after modification or exchange. This ASU became effective for the Company on January 1, 2022 and is not expected to have a material impact on the consolidated financial statements.

Significant Accounting Policies (Policies)

12 Months Ended

Jan. 02, 2022

Cash and Cash Equivalents, Policy [Policy Text Block]

Cash Equivalents and Restricted Cash

The Company considers all short-term, highly liquid investments with an original or a remaining maturity at purchase of ninety days or less to be cash equivalents. The Company’s investment portfolio included in cash equivalents is generally comprised of investments that meet high credit quality standards. The Company’s investment portfolio consists of money market accounts and funds. Restricted cash represents amounts pledged as cash security related to the use of credit cards.

Foreign Currency Transactions and Translations Policy [Policy Text Block]

Foreign Currency Transactions

All of the Company’s sales and cost of manufacturing are transacted in U.S. dollars. Accordingly, all monetary assets and liabilities of these foreign operations are translated into U.S. dollars at current period-end exchange rates and non-monetary assets and related elements of expense are translated using historical exchange rates. Income and expense elements are translated to U.S. dollars using the average exchange rates in effect during the period. Gains and losses from the foreign currency transactions of these subsidiaries are recorded as interest income and other expense, net in the Consolidated Statements of Operations.

The Company conducts a portion of its research and development activities in India and has sales and marketing activities in various countries outside of the United States. Most of these international expenses are incurred in local currency. Foreign currency transaction gains and losses, which are not significant, are included in interest income and other expense, net, as they occur. Operating expenses denominated in foreign currencies were approximately 21%, 18%and 19%of total operating expenses in fiscal years 2021, 2020, and 2019 respectively. The Company incurred a majority of these foreign currency expenses in India, the United Kingdom, China, Japan, Taiwan and Korea in fiscal years 2021, 2020, and 2019. The Company has not used derivative financial instruments to hedge its exposure to fluctuations in foreign currency and, therefore, is susceptible to fluctuations in foreign exchange gains or losses in its results of operations in future reporting periods.

Property, Plant and Equipment, Policy [Policy Text Block]

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is calculated on a straight-line basis over the estimated useful lives of the assets, generally one to seven years. Amortization of leasehold improvements is computed on a straight-line basis over the shorter of the lease term or the estimated useful lives of the assets, generally one to seven years.

Capitalized Internal-Use Software

The Company capitalizes costs related to development of hosted services that the Company provides to its customers and internal use of enterprise-level business and finance software in support of the Company’s operational needs. Costs incurred in the application development phase are capitalized and amortized on a straight-line basis over their useful lives, which are generally five years. Costs related to planning and other preliminary project activities and post-implementation activities are expensed as incurred. The Company tests these assets for impairment whenever events or changes in circumstances occur that could impact their recoverability.

Long-Lived Assets

The Company reviews the recoverability of its long-lived assets, such as property and equipment, annually and when events or changes in circumstances occur that indicate that the carrying value of the asset or asset group may not be recoverable. The assessment of possible impairment is based on the Company’s ability to recover the carrying value of the asset or asset group from the expected future pre-tax cash flows, undiscounted and without interest charges, of the related operations, as well as the useful lives applied to the assets. If these cash flows are less than the carrying value of the asset or asset group, an impairment loss is recognized for the difference between the estimated fair value and the carrying value, and the carrying value of the related assets is reduced by this difference. The measurement of impairment requires management to estimate future cash flows and the fair value of long-lived assets. During 2021, 2020 and 2019 the Company recognized losses (gain) on equipment with a net book value of ($5,000), $44,000 and $4,000, respectively. Approximately $35,000 of the equipment written-off during fiscal 2020 was included in Restructuring costs on the Company's Statements of Operations for year ended January 3, 2021.

Accounts Receivable [Policy Text Block]

Accounts Receivable Allowance

The Company estimates the amount of uncollectible accounts receivable at the end of each reporting period based on the aging of the receivable balance, current and historical customer trends, and communications with its customers. Amounts are written off only after considerable collection efforts have been made and the amounts are determined to be uncollectible. There were no significant write-off amounts for each of the 2021, 2020, and 2019 fiscal years. At the end of its 2021 and 2020 fiscal years, respectively, the Company had $62,000 and $0 in allowance for bad debts on its Consolidated Balance Sheets.

Standard Product Warranty, Policy [Policy Text Block]

Warranty Costs

The Company warrants finished goods against defects in material and workmanship under normal use for twelve months from the date of shipment. The Company’s liability is limited to the cost of repair or replacement of the defective part. The Company does not consider activities related to such warranties to be a separate performance obligation under ASC 606. The terms and conditions of sale generally do not allow for refunds or product returns other than for warranty repairs. The Company does not have significant product warranty related costs or liabilities for fiscal years 2021, 2020, and 2019.

Lessee, Leases [Policy Text Block]

Leases

The Company accounts for leases under ASC 842 and related ASUs. Under ASC 842, all significant lease arrangements are generally recognized at lease commencement. Operating lease right-of-use ("ROU"), assets and lease liabilities are recognized at the commencement date. A ROU asset and corresponding lease liability is not recorded for leases with an initial term of 12 months or less (short term leases) and the Company recognizes lease expense for these leases as incurred over the lease term.

ROU assets represent the Company’s right to use an underlying asset during the reasonably certain lease terms and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company primarily uses its incremental borrowing rate, based on the information available at commencement date, in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments related to initial direct cost and prepayments and excludes lease incentives. Lease expense is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are generally accounted for separately.

In accordance with ASU No. 2016-02, the Company recognized right-of-use assets of approximately $975,000 and lease liabilities of approximately $939,000 on the Company’s Consolidated Balance Sheet as of March 31, 2019, with no material impact to its Consolidated Statements of Operations. In 2020, pursuant its restructuring activities, the Company impaired the remaining right-of-use asset associated with its prior India location amounting to approximately $93,000, which is included with Restructuring costs on the Company's Consolidated Statements of Operations. As of January 2, 2022,the Company’s right-of-use assets were approximately $1.5 million and lease liabilities were approximately $1.6 million as presented on the Company’s Consolidated Balance Sheet. See Note 8.

Business Combinations Policy [Policy Text Block]

Business Combinations

The Company recognizes assets acquired (including goodwill and identifiable intangible assets) and liabilities assumed at fair value on the acquisition date. Subsequent changes to the fair value of such assets acquired and liabilities assumed are recognized in earnings, after the expiration of the measurement period, a period not to exceed 12 months from the acquisition date. Acquisition-related expenses and acquisition-related restructuring costs are recognized in earnings in the period in which they are incurred.

Goodwill and Intangible Assets, Policy [Policy Text Block]

Goodwill and Intangible Assets

Goodwill represents the excess fair value of consideration transferred over the fair value of net assets acquired in business combinations. The carrying value of goodwill and indefinite lived intangible assets are not amortized but are annually tested for impairment during the Company's fourth fiscal quarter, and more often if there is an indicator of impairment.

The Company recognized total goodwill of $185,000 in fiscal 2019 due to tax benefits that arose from intangible assets acquired in the SensiML acquisition including measurement period adjustments, occurring within 12 months from the date of acquisition, and therefore, accounted for under acquisition accounting. The Company's performs its annual goodwill impairment testing during the Company's fourth fiscal quarter. Subsequent to the Company's annual impairment testing in November 2021 and to January 2, 2022, there were no indicators of impairment that gave cause for additional impairment testing of goodwill. No impairment of goodwill has been recognized to date.

Intangible assets with finite useful lives are amortized on a straight-line basis over the periods benefited. The Company reviews the recoverability of its long-lived assets when events or changes in circumstances occur that indicate that the carrying value of the asset or asset group may not be recoverable. The assessment of possible impairment is based on the Company's ability to recover the carrying value of the asset or asset group from the expected future pre-tax cash flows (undiscounted and without interest charges) of the related operations. If these cash flows are less than the carrying value of such asset, an impairment loss is recognized for the difference between estimated fair value and carrying value. The measurement of impairment requires management to estimate future cash flows and the fair value of long-lived assets. The Company performed an annual impairment assessment in November 2021 and deemed no impairment was necessary for the current year. No impairment of intangible assets has been recognized to-date.

Advertising Cost [Policy Text Block]

Advertising

Costs related to advertising and promotion expenditures are charged to “Selling, general and administrative” expense in the consolidated statements of operations as incurred. Costs related to advertising and promotion expenditures were $47,000 in 2021, $76,000 in 2020, and $146,000 in 2019.

Share-based Payment Arrangement [Policy Text Block]

Stock-Based Compensation

The Company accounts for stock-based compensation under the provisions of the amended authoritative guidance, and related interpretations which require the measurement and recognition of expense related to the fair value of stock-based compensation awards. The fair value of stock-based compensation awards is measured at the grant date and re-measured upon modification, as appropriate. The Company uses the Black-Scholes option pricing model to estimate the fair value of employee stock options and rights to purchase shares under the 2019 Stock Plan, and 2009 Stock Plan,

1999 Employee Stock Purchase Plan (" ESPP"), consistent with the provisions of the amended authoritative guidance. The fair value of restricted stock awards ("RSA"), and restricted stock units ("RSU"), is based on the closing price of the Company’s common stock on the date of grant.

Using the Black-Scholes pricing model requires us to develop highly subjective assumptions, including the expected term of awards, expected volatility of our stock, expected risk-free interest rate and expected dividend rate over the term of the award. Our expected term of awards is based primarily on our historical experience with similar grants. Our expected stock price volatility for both stock options and ESPP shares is based on the historic volatility of our stock, using the daily average of the opening and closing prices and measured using historical data appropriate for the expected term. The risk-free interest rate assumption approximates the risk-free interest rate of a Treasury Constant Maturity bond with a maturity approximately equal to the expected term of the stock option or ESPP shares.

Since we recognize compensation expense only for awards ultimately expected to vest; therefore, we are required to develop an estimate of the historical pre-vest forfeiture experience and apply this to all stock-based awards. The fair value of restricted stock awards, or RSAs, and restricted stock units, or RSUs, is based on the closing price of our common stock on the date of grant. RSA and RSU awards which vest with service are expensed over the requisite service period. RSAs and RSU awards that are expected to vest based on the achievement of a performance goal are expensed over the estimated vesting period, which is estimated by management. We regularly review the assumptions used to compute the fair value of our stock-based awards and we revise our assumptions as appropriate. See Note 13.

Income Tax, Policy [Policy Text Block]

Accounting for Income Taxes

As part of the process of preparing our financial statements, we are required to estimate our income taxes in each of the jurisdictions in which we operate. This process involves estimating our actual current tax exposure together with assessing temporary differences resulting from different tax and accounting treatment of items, such as deferred revenue, allowance for doubtful accounts, the impact of equity awards, depreciation and amortization, and employee-related accruals. These differences result in deferred tax assets and liabilities, which are included on our balance sheets. We must then assess the likelihood that our deferred tax assets will be recovered from future taxable income. To the extent we believe that recovery is not likely, we must establish a valuation allowance. To the extent we establish a valuation allowance or increase this allowance in a period, we must include an expense within the tax provision in the statements of operations.

Significant management judgment is required in determining our provision for income taxes, deferred tax assets, liabilities and any valuation allowance recorded against our net deferred tax assets. Our deferred tax assets net of deferred tax liabilities relating to an ROU asset of $0.4 million, consisted primarily of net operating loss carryforwards, depreciation and amortization, amounted to approximately $61 million, tax effected, as of the end of 2021 . In evaluating our ability to recover our deferred tax assets within the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, uncertainty of projecting future taxable income and results of recent operations. As of January 2, 2022 , we had federal and state income tax net operating loss, or NOL, carryforwards of approximately $183.9 million and $94.4 million, respectively, which will expire at various dates from 2022 through 2041. Federal net operating losses generated in 2019 and forward of $55.3 million can be carried forward indefinitely. We had research credit carryforwards of approximately $3.7 million for federal and $4.7 million for state income tax purposes as of January 2, 2022 . If not utilized, the federal carryforwards will expire at various dates from 2022. The California credit can be carried forward indefinitely. We believe that it is more likely than not that the deferred tax assets and benefits from these federal and state NOL and credit carryforwards will not be realized. In recognition of this risk, we have recorded a valuation allowance of $60 million, tax-effected, as of the end of 2021 , due to uncertainties related to our ability to utilize our U.S. deferred tax assets before they expire.

The Company accounts for uncertainty in income taxes using a two-step approach for recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. The Company classifies the liability for unrecognized tax benefits as current to the extent that it anticipates payment (or receipt) of cash within one year. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes. Accrued interest and penalties are included within the accrued liabilities line in the Consolidated Balance Sheet.

Concentration Risk, Credit Risk, Policy [Policy Text Block]

Concentrations of Credit and Suppliers

Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash and cash equivalents and accounts receivable. Cash and cash equivalents are maintained with high quality institutions. The Company’s accounts receivables are denominated in U.S. dollars and are derived primarily from sales to customers located in North America, Europe and Asia Pacific. The Company performs ongoing credit evaluations of its customers and generally does not require collateral. See Note 14 for information regarding concentrations associated with accounts receivable.

The Company depends on a limited number of contract manufacturers, subcontractors, and suppliers for wafer fabrication, assembly, programming and test of its devices, and for the supply of programming equipment, and these services are typically provided by one supplier for each of the Company’s devices. The Company generally purchases these single or limited source services through standard purchase orders. Because the Company relies on independent subcontractors to perform these services, it cannot directly control its product delivery schedules, costs or quality levels. The Company’s future success also depends on the financial viability of its independent subcontractors.

Comprehensive Income, Policy [Policy Text Block]

Comprehensive Income (Loss)

Comprehensive income (loss) includes all temporary changes in equity (net assets) during a period from non-owner sources. The Company’s comprehensive loss equaled to net loss for all periods presented.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Adopted New Accounting Pronouncements:

In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes, which removes certain exceptions to the general principles of ASC 740, in order to reduce the cost and complexity of its application. These changes include elimination to the exceptions for (1) Intra-period tax allocation, (2) Deferred tax liabilities related to outside basis differences, and (3) Year-to-date losses in interim periods. This standard is effective for the fiscal years beginning after December 15, 2020. The Company adopted ASU No. 2019-12, as of January 4, 2021, without significant impact on its Consolidated Financial Statements.

New Accounting Pronouncements Pending Adoption

In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which address issues identified as a result of the complexity associated with applying generally accepted accounting principles for certain financial instruments with characteristics of liabilities and equity. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Board specified that an entity should adopt the guidance as of the beginning of its annual fiscal year. The Company is in process of assessing the impact of ASU No. 2020-06 on its Consolidated Financial Statements.

In May 2021, ASU No. 2021-04, Issuer’s Accounting for Certain Modifications of Exchanges of Freestanding Equity-Classified Written Call Options, was issued to clarify the accounting for modifications or exchanges of freestanding equity-classified written call options, such was warrants, that remain equity classified after modification or exchange. This ASU became effective for the Company on January 1, 2022 and is not expected to have a material impact on the consolidated financial statements.