Everspin (MRAM) 10-K 4 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 25, 2021	Jun. 30, 2020
Document And Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
Entity File Number	001-37900
Entity Registrant Name	Everspin Technologies, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-2640654
Entity Address, Address Line One	5670 W. Chandler Boulevard
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Chandler
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85226
City Area Code	480
Local Phone Number	347-1111
Title of 12(b) Security	Common Stock, par value $0.0001
Trading Symbol	MRAM
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		19,077,432
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0001438423
Amendment Flag	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float			$ 105.3

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 14,599	$ 14,487
Accounts receivable, net	7,607	5,799
Inventory	5,721	7,863
Prepaid expenses and other current assets	270	539
Total current assets	28,197	28,688
Property and equipment, net	1,946	3,479
Right-of-use assets	2,313	3,132
Other assets	73	73
Total assets	32,529	35,372
Current liabilities:
Accounts payable	2,224	2,873
Accrued liabilities	2,232	2,727
Current portion of long-term debt	4,242	670
Operating lease liabilities	1,508	1,582
Other liabilities	31	42
Total current liabilities	10,237	7,894
Long-term debt, net of current portion	3,748	7,149
Operating lease liabilities, net of current portion	903	1,840
Long-term income tax liability	229
Total liabilities	15,117	16,883
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value per share; 5,000,000 shares authorized; no shares issued and outstanding as of December 31, 2020 and 2019
Common stock, $0.0001 par value per share; 100,000,000 shares authorized; 19,031,556 and 18,081,753 shares issued and outstanding as of December 31, 2020 and 2019	2	2
Additional paid-in capital	174,584	167,149
Accumulated deficit	(157,174)	(148,662)
Total stockholders' equity	17,412	18,489
Total liabilities and stockholders' equity	$ 32,529	$ 35,372

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Balance Sheets
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares Issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	19,031,556	18,081,753
Common stock, shares outstanding	19,031,556	18,081,753

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Total revenue	$ 42,031	$ 37,503
Cost of sales	23,942	19,172
Gross profit	18,089	18,331
Operating expenses:
Research and development	10,896	14,183
General and administrative	10,773	12,414
Sales and marketing	3,983	5,364
Restructuring		782
Total operating expenses	25,652	32,743
Loss from operations	(7,563)	(14,412)
Interest expense	(665)	(747)
Other (expense) income, net	(24)	490
Net loss before income taxes	(8,252)	(14,669)
Income tax expense	(260)
Net loss and comprehensive loss	$ (8,512)	$ (14,669)
Net loss per common share, basic and diluted	$ (0.45)	$ (0.85)
Weighted-average shares used to compute net loss per common share, basic and diluted	18,782,287	17,317,042
Product sales
Total revenue	$ 39,848	$ 34,595
Product sales
Total revenue	39,848	34,595
Licensing, royalty and other revenue
Total revenue	$ 2,183	$ 2,908

Statements of Operations and _2

Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating expenses include stock-based compensation as follows:
Total stock-based compensation	$ 3,968	$ 3,554
Research and development
Operating expenses include stock-based compensation as follows:
Total stock-based compensation	903	736
General and administrative
Operating expenses include stock-based compensation as follows:
Total stock-based compensation	2,710	2,460
Sales and marketing
Operating expenses include stock-based compensation as follows:
Total stock-based compensation	$ 355	$ 358

Statements of Stockholders' Equ

Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Total
Balance at Dec. 31, 2018	$ 2	$ 158,912	$ (133,993)	$ 24,921
Balance (in shares) at Dec. 31, 2018	17,095,456
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock incentive plans		282		282
Issuance of common stock under stock incentive plans (in shares)	97,310
Issuance of common stock in at-the-market offering, net of issuance costs		4,734		4,734
Issuance of common stock (in shares)	888,987
Modification of warrant in conjunction with 2019 Credit Facility		(19)		(19)
Stock-based compensation expense		3,240		3,240
Net loss			(14,669)	(14,669)
Balance at Dec. 31, 2019	$ 2	167,149	(148,662)	18,489
Balance (in shares) at Dec. 31, 2019	18,081,753
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock incentive plans		1,595		1,595
Issuance of common stock under stock incentive plans (in shares)	481,376
Issuance of common stock in at-the-market offering, net of issuance costs		2,084		2,084
Issuance of common stock (in shares)	468,427
Stock-based compensation expense		3,604		3,604
Issuance of warrant		152		152
Net loss			(8,512)	(8,512)
Balance at Dec. 31, 2020	$ 2	$ 174,584	$ (157,174)	$ 17,412
Balance (in shares) at Dec. 31, 2020	19,031,556

Statement of Cash Flows

Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net loss	$ (8,512)	$ (14,669)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,982	1,694
Loss on disposal of property and equipment	30	20
Stock-based compensation	3,968	3,554
Non-cash gain on warrant revaluation	(2)	(3)
Non-cash interest expense	323	290
Changes in operating assets and liabilities:
Accounts receivable	(1,808)	1,723
Inventory	2,142	1,234
Prepaid expenses and other current assets	269	149
Accounts payable	(820)	202
Accrued liabilities	(303)	(2,210)
Lease liabilities	(192)	(100)
Net cash used in operating activities	(2,923)	(8,116)
Cash flows from investing activities
Purchases of property and equipment	(320)	(861)
Net cash used in investing activities	(320)	(861)
Cash flows from financing activities
Payments on debt		(4,840)
Payments of debt issuance costs		(80)
Payments on finance lease obligation	(9)	(11)
Proceeds from exercise of stock options and purchase of shares in employee stock purchase plan	1,280	282
Proceeds from issuance of common stock in at-the-market offering, net of issuance costs	2,084	4,734
Net cash provided by financing activities	3,355	85
Net increase (decrease) in cash and cash equivalents	112	(8,892)
Cash and cash equivalents at beginning of period	14,487	23,379
Cash and cash equivalents at end of period	14,599	14,487
Supplementary cash flow information:
Interest paid	342	480
Cash paid for taxes		48
Operating cash flows paid for operating leases	1,736	1,693
Financing cash flows paid for finance leases	9	11
Non-cash investing and financing activities:
Right-of-use assets obtained in exchange for new operating leases		23
Increase of right-of-use asset and lease liability due to lease modification	545	895
Purchases of property and equipment in accounts payable and accrued liabilities	216	57
Modification of warrant		$ 36
Issuance of warrant with debt	$ 152

Organization and Nature of Busi

Organization and Nature of Business	12 Months Ended
	Dec. 31, 2020
Organization and Nature of Business
Organization and Nature of Business	1. Organization and Operations Everspin Technologies, Inc. (the Company) was incorporated in Delaware on May 16, 2008. The Company’s magnetoresistive random access memory (MRAM) solutions offer the persistence of non-volatile memory with the speed and endurance of random access memory (RAM) and enable the protection of mission critical data particularly in the event of power interruption or failure. The Company’s MRAM solutions allow its customers in key markets, such as industrial, medical, automotive/transportation, aerospace and data center, to design high performance, power-efficient and reliable systems without the need for bulky batteries or capacitors. Ability to continue as a going concern The Company believes that its existing cash and cash equivalents as of December 31, 2020, coupled with its anticipated growth and sales levels and availability under its credit facility, will be sufficient to meet its anticipated cash requirements for at least the next 12 months from the financial statement issuance date. The Company’s future capital requirements will depend on many factors, including its growth rate, the timing and extent of its spending to support research and development activities, the timing and cost of establishing additional sales and marketing capabilities, and the introduction of new products. The Company may be required at some point in the future to seek additional equity or debt financing, to sustain operations beyond that point, and such additional financing may not be available on acceptable terms or at all. If the Company is unable to raise additional capital or generate sufficient cash from operations to adequately fund its operations, it will need to curtail planned activities to reduce costs. Doing so will likely harm its ability to execute on its business plan.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP). The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, fair value of assets and liabilities, inventory, product warranty reserves, income taxes, and stock-based compensation. The Company believes its estimates and assumptions are reasonable; however, actual results may differ from the Company’s estimates. Segments The Company’s chief operating decision maker is its Chief Executive Officer who reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance for the entire Company. As a result, the Company has single operating and reportable segment. Cash and Cash Equivalents The Company considers all highly liquid, short-term investments with maturity dates of 90 days or less at the date of purchase to be cash equivalents. The Company’s cash equivalents consist solely of money market funds. Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. The Company generally does not require collateral or other security in support of accounts receivable. Allowances would be provided for individual accounts receivable when the Company becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy, deterioration in the customer’s operating results or change in financial position. If circumstances related to customers change, estimates of the recoverability of receivables would be further adjusted. The Company also considers a number of factors in evaluating the sufficiency of its allowance for doubtful accounts, including the length of time receivables are past due, significant one-time events, creditworthiness of customers and historical experience. Account balances would be charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The Company’s evaluation determined that no material allowance for doubtful accounts was necessary at December 31, 2020 and 2019. The Company establishes an allowance for product returns. The Company analyzes historical returns, current economic trends and changes in customer demand and acceptance of products when evaluating the adequacy of sales returns. Returns are processed as credits on future purchases and, as a result, the allowance is recorded against the balance of trade accounts receivable. In addition, the Company establishes an allowance for estimated price concessions related to its distributer agreements. The Company estimates credits to distributors based on the historical rate of credits provided to distributors relative to sales. At December 31, 2020 and 2019, the allowance for product returns and price concessions was $238,000 and $231,000, respectively. Accounts receivable, net consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 ​ 2019 Trade accounts receivable ​ $ 7,590 ​ $ 5,454 Unbilled accounts receivable ​ ​ 255 ​ ​ 576 Allowance for product returns and price concessions ​ (238) ​ (231) Accounts receivable, net ​ $ 7,607 ​ $ 5,799 ​ Concentration of Credit Risk Financial instruments that potentially expose the Company to a concentration of credit risk consist principally of cash and cash equivalents that are held by a financial institution in the United States and accounts receivable. Amounts on deposit with a financial institution may at times exceed federally insured limits. The Company maintains its cash accounts with high credit quality financial institutions and accordingly, minimal credit risk exists with respect to the financial institutions. Significant customers are those which represent more than 10% of the Company’s total revenue or net accounts receivable balance at each respective balance sheet date. For the purposes of this disclosure, the Company defines “customer” as the entity that is purchasing the products or licenses directly from the Company, which includes the distributors of the Company’s products in addition to end customers that the Company sells to directly. For each significant customer, revenue as a percentage of total revenue and accounts receivable as a percentage of total accounts receivable, net are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ Accounts Receivable ​ ​ Year Ended December 31, ​ December 31, Customers ​ 2020 2019 2020 2019 Celestica Shared Service Centre ​ 29 % 21 % 29 % 41 % Customer B ​ 11 % * ​ 25 % 11 % Customer C ​ * ​ 12 % * ​ * ​ Customer D ​ * ​ 12 % * ​ * ​ Customer E ​ * ​ 10 % * ​ * ​ * Less than 10% Inventory Inventory is valued at the lower of cost, using the first-in, first-out or specific identification method, or market. The carrying value of inventory is adjusted for excess and obsolescence based on the Company’s evaluation which takes into consideration historical and expected future demand, the effect new products may have on the sale of existing products, technological obsolescence, and other factors including inventory age and shipment. At the point of loss recognition, a new lower cost basis for that inventory is established and subsequent changes in facts and circumstances do not result in the restoration or increase in that new cost basis. Fair Value of Financial Instruments Fair value is defined as an exit price, representing the amount that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants. The framework for measuring fair value provides a three-tier hierarchy prioritizing inputs to valuation techniques used in measuring fair value as follows: Level 1 Level 2 Level 3 The carrying value of accounts receivable, accounts payable, and other accruals readily convertible into cash approximate fair value because of the short-term nature of the instruments. As of December 31, 2020, based on Level 2 inputs and the borrowing rates available to the Company for loans with similar terms and consideration of the Company’s credit risk, the carrying value of the Company’s variable interest rate debt, excluding unamortized debt issuance costs, approximates fair value. The Company’s financial instruments consist of Level 1 assets and a Level 3 liability. Where quoted prices are available in an active market, securities are classified as Level 1. Level 1 assets consist of highly liquid money market funds that are included in cash equivalents. The Company’s Level 3 liability consists of warrants issued in connection with the 2019 Credit Facility (Note 6). The change in the fair value of the warrant liability during the year ended December 31, 2020 was immaterial. The following tables sets forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 14,669 $ — $ — $ 14,669 Total assets measured at fair value ​ $ 14,669 $ — $ — $ 14,669 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant liability ​ $ — $ — $ 31 $ 31 Total liabilities measured at fair value ​ $ — $ — $ 31 $ 31 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 12,367 $ — $ — $ 12,367 Total assets measured at fair value ​ $ 12,367 $ — $ — $ 12,367 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant liability ​ $ — $ — $ 33 $ 33 Total liabilities measured at fair value ​ $ — $ — $ 33 $ 33 ​ Property and Equipment Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation begins at the time the asset is placed in service. Maintenance and repairs are charged to operations as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives of the assets: ​ ​ ​ ​ ​ Useful Lives Computer and network equipment ​ 2 years Manufacturing equipment ​ 2 – 7 years Furniture and fixtures ​ 7 years Software ​ 3 years Leasehold improvements ​ 2 years (not to exceed the lease life) ​ Costs incurred to develop software for internal use during the application development phase are capitalized and amortized over such software’s estimated useful life. Costs related to the design or maintenance of internal-use software are included in operating expenses as incurred. During 2020, no Impairment of Long-lived Assets The Company evaluates its long-lived assets, including property and equipment, at the asset group level, for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. If such events or changes in circumstances occur, for purposes of this assessment, long-lived assets are grouped with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability of these assets is measured by comparison of the carrying amount of each asset group to the future undiscounted cash flows the asset group is expected to generate over its remaining life. If the asset group is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. There have been no impairments of the Company’s long-lived assets during either of the periods presented. Leases The Company leases office, lab, manufacturing space and equipment in various locations with initial lease terms of up to five years. These leases require monthly lease payments that may renewal options renew extend two The Company determines if an arrangement is a lease at inception. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. The classification of the Company's leases as operating or finance leases along with the initial measurement and recognition of the associated ROU assets and lease liabilities is performed at the lease commencement date. The measurement of lease liabilities is based on the present value of future lease payments over the lease term. The Company uses its incremental borrowing rate, based on the information available at commencement date, to determine the present value of lease payments when its leases do not provide an implicit rate. The Company uses the implicit rate when readily determinable. The ROU asset is based on the measurement of the lease liability, includes any lease payments made prior to or on lease commencement and excludes lease incentives and initial direct costs incurred, as applicable. Lease expense for the Company’s operating leases is recognized on a straight-line basis over the lease term. Amortization expense for ROU assets associated with finance leases is recognized on a straight-line basis over the shorter of the useful life of the asset or the lease term and interest expense associated with finance leases is recognized on the balance of the lease liability using the effective interest method based on the estimated incremental borrowing rate. The Company has lease agreements with lease and non-lease components. The Company has elected to not separate lease and non-lease components for any leases involving real estate and office equipment classes of assets and, as a result, accounts for the lease and non-lease components as a single lease component. The Company has elected to separate lease and non-lease components for any leases involving manufacturing facility classes of assets. Further, the Company elected the short-term lease exception policy, permitting it to not apply the recognition requirements of this standard to leases with terms of 12 months or less (short-term leases) for all classes of assets. As of December 31, 2020, the Company did not have any short-term leases. Operating leases are included in right-of-use assets, operating lease liabilities, and operating lease liabilities, net of current portion in the Company’s balance sheet. Finance leases are included in property and equipment, net, other liabilities, and other long-term liabilities in the Company’s balance sheet. Debt Issuance Costs The Company defers and amortizes issuance costs, underwriting fees, end of term payments, and related expenses incurred in connection with the issuance of debt instruments using the effective interest method over the terms of the respective instruments. Debt issuance costs are reflected as a direct reduction of the carrying amount of the related debt liability. Revenue Recognition The Company recognizes revenue when a customer obtains control of the promised products or services, in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. Revenue is recognized net of allowances for returns and price concessions, and any taxes collected from customers, which are subsequently remitted to governmental authorities. Nature of Products and Services The Company’s revenue is derived from the sale of MRAM-based products in discrete unit form, licenses of and royalties on its MRAM and magnetic sensor technology, the sale of backend foundry services and design services to third parties. Sales of products in discrete unit form are recognized at a point in time, revenue related to licensing agreements is recognized when the Company has delivered control of the technology, revenue related to royalty agreements is recognized in the period in which sales generated from products sold using the Company’s technology occurs, sales of backend foundry services are recognized over time, and design services to third parties are recognized either at a point in time or over time, depending on the nature of the services. Product Revenue For products sold in their discrete form, the Company either sells its products directly to original equipment manufacturers (OEMs), original design manufacturers (ODMs) and contract manufacturers (CMs), or through a network of distributors, who in turn sell to those customers. For sales directly to OEMs, ODMs and CMs, revenue is recognized when the OEM, ODM or CM obtains control of the product, which occurs at a point in time, generally upon shipment to the customer. The Company sells the majority of its products to its distributors at a uniform list price. However, distributors may resell the Company’s products to end customers at a very broad range of individually negotiated price points. Distributors are provided with price concessions subsequent to the delivery of product to them and such amounts are dependent on the end customer and product sales price. The price concessions are based on a variety of factors, including customer, product, quantity, geography and competitive differentiation. Price protection rights grant distributors the right to a credit in the event of declines in the price of the Company’s products. Under these circumstances, the Company remits back to the distributor a portion of their original purchase price after the resale transaction is completed in the form of a credit against the distributors’ outstanding accounts receivable balance. The credits are on a per unit basis and are not given to the distributor until the distributor provides information regarding the sale to their end customer. The Company estimates these credits and records such estimates in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of an allowance for price concessions due to distributors. The Company estimates credits to distributors based on the historical rate of credits provided to distributors relative to sales. Revenue on shipments to distributors is recorded when control of the products has been transferred to the distributor. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company estimates its product return liability by analyzing its historical returns, current economic trends and changes in customer demand and acceptance of products. The Company has received insignificant returns to date and believes that returns of its products will continue to be minimal. Upon the transfer of control, generally at shipment, the Company records a trade receivable for the selling price as there is a legally enforceable obligation of the distributor to pay for the product delivered, an allowance is recorded for the estimated discount that will be provided to the distributor, and the net of these amounts is recorded as revenue on the statement of operations. License Revenue For licenses of technology, recognition of revenue is dependent upon whether the Company has delivered rights to the technology, and whether there are future performance obligations under the contract. In some instances, the license agreements call for future events or activities to occur in order for milestones amounts to become due from the customer. The terms of such agreements include payment to the Company of one or more of the following: non-refundable upfront fees; and royalties on net sales of licensed products. Historically, these license agreements have not included other future performance obligations for the Company once the license has been transferred to the customer. Revenue from non-refundable upfront payments is recognized when the license is transferred to the customer and the Company has no other performance obligations. Royalties Revenue from sales-based royalties from licenses of the Company’s technology are recognized at the later of when (1) the sale occurs or (2) the performance obligation to which some or all of the sales-based royalty has been allocated is satisfied (in whole or in part). The Company will record an unbilled receivable (within accounts receivable, net) for the portion of sales-based royalties that have been earned, but not invoiced at the end of each reporting period. Other Revenue For certain revenue streams, the Company recognizes revenue based on the pattern of transfer of the services. The Company uses the input method of measuring costs incurred to date compared to total estimated costs to be incurred under the contract as this method most faithfully depicts its performance. The Company will record an unbilled receivable (within accounts receivable, net) for the portion of the work that has been completed but not invoiced at the end of each reporting period. At the inception of each agreement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price by using the most likely amount method. If it is probable that a significant reversal of cumulative revenue would not occur, the associated milestone value is included in the transaction price. At the end of each subsequent reporting period, the Company re-evaluates the probability or achievement of each such milestone and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. Product Warranty The Company generally sells products with a limited warranty of product quality and a limited indemnification of customers against intellectual property infringement claims related to the Company’s products. The Company accrues for known warranty and indemnification issues if a loss is probable and can be reasonably estimated, and accrues for estimated losses incurred for unidentified issues based on historical experience. A warranty liability was not recorded at December 31, 2020 and 2019, as the estimated future warranty costs were not material based on the Company’s historical experience. Research and Development Research and development expenses are incurred in support of internal development programs or as part of the Company’s joint development agreement with GLOBALFOUNDRIES and joint collaboration agreement with Silterra Malaysia Sdn. Bhd. (see Note 10). Research and development expenses include personnel-related costs (including stock-based compensation), circuit design costs, purchases of materials and laboratory supplies, fabrication and packaging of experimental integrated circuit products, depreciation of research and development related capital equipment and overhead, and are expensed as incurred. Stock-based Compensation Stock-based compensation arrangements include stock option grants and restricted stock unit (RSU) awards under the Company’s equity incentive plans, as well as shares issued under the Company’s Employee Stock Purchase Plan (ESPP), through which employees may purchase the Company’s common stock at a discount to the market price. The Company measures its stock option grants based on the estimated fair value of the options as of the grant date using the Black-Scholes option-pricing model. Stock-based compensation expense is recognized over the requisite service period using the straight-line method. The Company accounts for forfeitures as they occur. Expected volatility. Risk-free interest rate. Expected term. Dividend yield. Income Taxes The Company uses the liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company must then assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. Net Loss per Common Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding for the period less shares subject to repurchase, without consideration of potentially dilutive securities. Diluted net loss per common share is the same as basic net loss per common share since the effect of potentially dilutive securities is anti-dilutive. Recently Issued Pronouncements In December 2019, the FASB issued Accounting Standards Update (ASU) 2019-12, Income Taxes (Topic 740). Simplifying the Accounting for Income Taxes. The new guidance eliminates certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, and the recognition of deferred tax liabilities for outside basis differences. It also clarifies and simplifies other aspects of the accounting for income taxes. ASU 2019-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption is permitted. The adoption of ASU 2019-12 is not expected to have a material effect on the Company’s financial statements and related disclosures. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which amends the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. As the Company is a smaller reporting company, ASU 2016-13 is effective for annual reporting periods, and interim periods within those years, beginning after December 15, 2022, and requires a cumulative effect adjustment to the balance sheet as of the beginning of the first reporting period in which the guidance is effective. In April 2019, the FASB issued ASU No. 2019-04, Codification Improvements Financial Instruments-Credit Losses (Topic 326). The new ASU provides narrow-scope amendments to help apply ASU No. 2016-13. The Company is evaluating the impact of the adoption of ASU 2016-13 on its financial statements.

Revenue

Revenue	12 Months Ended
	Dec. 31, 2020
Revenue.
Revenue	3. Revenue The Company sells the majority of its products to its distributors, but also to OEMs. The Company also recognizes revenue under licensing and royalty agreements with some customers. The following table presents the Company’s revenues disaggregated by sales channel (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ Distributor ​ $ 26,027 ​ $ 24,724 ​ Non-distributor ​ ​ 16,004 ​ ​ 12,779 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​ ​ ​ ​ The following table presents the Company’s revenues disaggregated by timing of recognition (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ Point in time ​ $ 40,846 ​ $ 35,665 ​ Over time ​ ​ 1,185 ​ ​ 1,838 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​ ​ ​ The following table presents the Company’s revenues disaggregated by type (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ Product sales ​ $ 39,848 ​ $ 34,595 ​ Royalties ​ ​ 998 ​ ​ 1,070 ​ Other revenue ​ ​ 1,185 ​ ​ 1,838 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​ ​ The Company recognizes revenue in three geographic regions: North America; Europe, Middle East and Africa (EMEA); and Asia-Pacific (APAC). The following table presents the Company’s revenues disaggregated by the geographic region to which the product is delivered or licensee is located (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ APAC ​ $ 29,480 ​ $ 20,093 ​ North America ​ ​ 9,253 ​ ​ 8,690 ​ EMEA ​ ​ 3,298 ​ ​ 8,720 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​ ​

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2020
Balance Sheet Components
Balance Sheet Components	4. Balance Sheet Components Inventory Inventory consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2020 2019 Raw materials ​ $ 329 ​ $ 119 Work-in-process ​ 4,910 ​ 6,329 Finished goods ​ 482 ​ 1,415 Total inventory ​ $ 5,721 ​ $ 7,863 ​ Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Manufacturing equipment ​ $ 12,296 ​ $ 12,228 Computer and network equipment ​ ​ 917 ​ ​ 877 Furniture and fixtures ​ ​ 112 ​ ​ 112 Software ​ ​ 925 ​ ​ 925 Leasehold improvements ​ ​ 1,444 ​ ​ 1,444 Total property and equipment, gross ​ ​ 15,694 ​ ​ 15,586 Less: accumulated depreciation ​ ​ (13,748) ​ ​ (12,107) Total property and equipment, net ​ $ 1,946 ​ $ 3,479 ​ Depreciation and amortization expense during the years ended December 31, 2020 and 2019 was $2.0 million and $1.7 million, respectively. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2020 2019 Payroll-related expenses ​ $ 1,274 ​ $ 1,236 Joint development agreement expenses ​ ​ — ​ ​ 170 Inventory ​ ​ 416 ​ ​ 87 Restructuring expenses ​ — ​ 782 Other ​ 542 ​ 452 Total accrued liabilities ​ $ 2,232 ​ $ 2,727 ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies
Commitments and Contingencies	5. Commitments and Contingencies Leases Operating leases consist primarily of office space expiring at various dates through 2022. The undiscounted future non-cancellable lease payments under the Company’s operating leases were as follows (in thousands): ​ ​ ​ ​ ​ As of December 31, 2020 Amount ​ 2021 ​ $ 1,603 ​ 2022 ​ ​ 861 ​ 2023 ​ ​ 68 ​ Total undiscounted lease payments ​ ​ 2,532 ​ Less: present value adjustment ​ ​ (121) ​ Total operating lease liabilities ​ ​ 2,411 ​ Less: current portion of operating lease liabilities ​ ​ (1,508) ​ Total operating lease liabilities, net of current portion ​ $ 903 ​ ​ Other information related to the Company's operating lease liabilities was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Weighted-average remaining lease term (years) 1.74 ​ ​ 2.06 Weighted-average discount rate ​ 6.00 % ​ 6.00 % ​ Lease costs for the Company’s operating leases were $1.5 and $1.6 million for the years ended December 31, 2020 and 2019, respectively. Variable lease payments for operating leases were immaterial for the years ended December 31, 2020 and 2019. Lease costs for the Company’s finance lease were immaterial for the years ended December 31, 2020 and 2019. Legal Proceedings From time to time, the Company may become involved in legal proceedings arising from the ordinary course of its business. Management is currently not aware of any matters that it expects will have a material adverse effect on the financial position, results of operations or cash flows of the Company. Indemnifications In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance.

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt
Debt	6. Debt 2019 Credit Facility In August 2019, the Company executed an Amended and Restated Loan and Security Agreement (2019 Credit Facility), which amended and restated the Company’s prior loan and security agreement (2017 Credit Facility), providing for a formula revolving line of credit (Line of Credit) and a term loan (2019 Term Loan) with Silicon Valley Bank (SVB) to refinance in full the outstanding principal balance of $8.0 million under the 2017 Credit Facility. In August 2019, the Company paid the final payment of $0.8 million, which was due upon the refinancing of the 2017 Credit Facility. In July 2020, the Company executed the first amendment to the 2019 Credit Facility with SVB. The amendment, among other things, extended the initial 12 months interest-only period for the 2019 Term Loan to a 16 months interest-only period and lowered the floor interest rate. The floor interest rates for 2019 Term Loan and the Line of Credit were reduced from 4.75% and 6.75% to 3.75% and 4.75%, respectively. ​ The Line of Credit under the amended 2019 Credit Facility allows for a maximum draw of $5.0 million, subject to a formula borrowing base, has a two-year term and bears interest at a floating rate equal to the Wall Street Journal (WSJ) prime rate plus 1.5%, per annum, subject to a floor of 4.75%. As of December 31, 2020, the interest rate was 4.75%. The Line of Credit required a commitment fee of 1.6% of the maximum availability of the Line of Credit, which was paid in August 2019 upon closing, and was accounted for as a debt discount. The Line of Credit also provides for a termination fee equal to 1% of the maximum availability under the Line of Credit, which is due in case of a termination of the Line of Credit prior to the scheduled maturity date, and an unused facility fee equal to 0.125% per annum of the average unused portion of the Line of Credit, which is expensed as incurred. At execution, $2.0 million from the Line of Credit was used to refinance a portion of the outstanding balance of the 2017 Credit Facility, and $3.0 million remains available under the Line of Credit, subject to borrowing base availability. As of December 31, 2020, the effective interest rate under the Line of Credit was 10.18% and the outstanding balance was $2.0 million. The Term Loan under the amended 2019 Credit Facility provides for a $6.0 million term loan, which was used to refinance the remaining balance of the 2017 Credit Facility. The 2019 Term Loan has a term of 46 months , and a 16-month interest only period followed by 30 months of equal principal payments, plus accrued interest. The 2019 Term Loan bears interest at a floating rate equal to the WSJ prime rate minus 0.75%, subject to a floor of 3.75%. As of December 31, 2020, the interest rate was 3.75%. A final payment of 7% of the original principal amount of the 2019 Term Loan must be made when the 2019 Term Loan is prepaid or repaid, whether at maturity or as a result of a prepayment or acceleration or otherwise. The additional payment, which is accounted for as a debt discount, is being accreted using the effective interest method. The 2019 Term Loan has a prepayment fee equal to 2% of the total commitment, which is due only if the 2019 Term Loan is prepaid prior to the scheduled maturity date for any reason. As of December 31, 2020, the effective interest rate under the 2019 Term Loan was 7.85% and the outstanding balance was $6.0 million. ​ In conjunction with entering into the 2019 Credit Facility, on August 5, 2019, the Company and SVB amended and restated the warrant issued to SVB in connection with the first amendment to the 2017 Credit Facility. See Note 7 for more information. ​ In conjunction with entering into the first amendment to the 2019 Credit Facility, on July 15, 2020, the Company issued a warrant to SVB to purchase 21,500 shares of the Company’s common stock at an exercise price of $0.01 per share. See Note 7 for more information. ​ Collateral for the 2019 Credit Facility includes all of the Company’s assets except for intellectual property. The Company is required to comply with certain covenants under the 2019 Credit Facility, including requirements to maintain a minimum cash balance and availability under the Line of Credit, and restrictions on certain actions without the consent of the lender, such as limitations on its ability to engage in mergers or acquisitions, sell assets, incur indebtedness or grant liens or negative pledges on its assets, make loans or make other investments. Under these covenants, the Company is prohibited from paying cash dividends with respect to its capital stock. The Company was in compliance with all covenants at December 31, 2020. The 2019 Credit Facility contains a material adverse effect clause which provides that an event of default will occur if, among other triggers, an event occurs that could reasonably be expected to result in a material adverse effect on the Company’s business, operations or condition, or on the Company’s ability to perform its obligations under the term loan. As of December 31, 2020, management does not believe that it is probable that the clause will be triggered within the next 12 months, and therefore the term loan is classified as long-term debt. The carrying value of the Company’s 2019 Credit Facility at December 31, 2020, was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current Long-Term ​ ​ ​ ​ Portion ​ Debt ​ Total Credit Facility ​ $ 4,400 ​ $ 4,020 ​ $ 8,420 Unamortized debt discounts ​ (158) ​ (272) ​ (430) Net carrying value ​ $ 4,242 ​ $ 3,748 ​ $ 7,990 ​ The carrying value of the Company’s 2019 Credit Facility at December 31, 2019, was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current Long-Term ​ ​ ​ ​ Portion ​ Debt ​ Total Credit Facility ​ $ 800 ​ $ 7,620 ​ $ 8,420 Unamortized debt discounts ​ ​ (130) ​ (471) ​ (601) Net carrying value ​ $ 670 ​ $ 7,149 ​ $ 7,819 ​ The table below includes the principal repayments due under the 2019 Credit Facility as of December 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Principal Repayment as of December 31, 2020 2021 ​ ​ 4,400 2022 ​ ​ 2,400 2023 ​ ​ 1,620 Total principal repayments ​ $ 8,420 ​

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity
Stockholders' Equity	7. Stockholders’ Equity Common Stock Common stockholders are entitled to dividends if and when declared by the board of directors. As of December 31, 2020, no At-the-Market Sales Agreement In August 2019, the Company entered into an Open Market Sale Agreement (2019 Sales Agreement) with Jefferies, LLC (Jefferies) for the offer and sale of shares of its common stock having an aggregate offering of up to $25.0 million from time to time through Jefferies, acting as the Company’s sales agent. The issuance and sale of these shares by the Company pursuant to the 2019 Sales Agreement are deemed an “at-the-market” (ATM) offering under the Securities Act of 1933, as amended. Under the 2019 Sales Agreement, the Company agreed to pay Jefferies a commission of up to 3% of the gross proceeds of any sales made pursuant to the 2019 Sales Agreement. During the year ended December 31, 2020, the Company received net proceeds of $2.1 million after deducting commissions and expenses payable by the Company, from the sale of 468,427 shares of common stock pursuant to the 2019 Sales Agreement. The Company suspended sales under the 2019 Sales Agreement in March 2020 and terminated the ATM program in November 2020. Reserved Shares of Common Stock The Company had reserved shares of common stock for future issuance as follows: ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 ​ 2019 Options issued and outstanding 2,272,905 1,931,903 Shares available for future option grants 179,219 638,227 RSUs subject to future vesting ​ 416,742 ​ 211,962 Common stock warrants 49,336 27,836 Total 2,918,202 2,809,928 ​ Warrants In conjunction with the credit facility, Silicon Valley Bank held warrants to purchase 9,229 shares of the Company’s common stock at an exercise price of $26.00 per share. These warrants were cancelled when the Company entered into the first amendment to the 2017 Credit Facility (see Note 6) and the Company subsequently issued a warrant to SVB for the purchase of 9,375 shares of the Company’s common stock at an exercise price of $8.91 per share. The warrant can be exercised at any time and expires five years after the date of issuance. The Company estimated the fair value of the warrant as $43,000 on the date of issuance using the Black-Scholes option pricing model. The warrant is classified within equity and was recorded as a discount to the debt to be amortized into interest expense over the remaining term of the loan using the effective interest method. ​ In conjunction with entering into the 2019 Credit Facility, on August 5, 2019, the Company and SVB amended and restated the warrant issued to SVB in connection with the first amendment to the 2017 Credit Facility, to add an option by SVB to put the warrant back to the Company for $50,000 upon expiration or a liquidity event, to be prorated if SVB exercises a portion of the warrant. The warrant expires on July 6, 2023. As of August 5, 2019, the warrant was classified as a liability and recorded at fair value within other liabilities in the Company’s balance sheet. Due to the put right, the warrant is subject to fair value remeasurement at each subsequent reporting date until the exercise or expiration of the warrant. The fair value of the warrant is estimated using a Black-Scholes valuation model. Any resulting change in the fair value of the warrant will be recorded as other income, net in the Company’s statements of operations and comprehensive loss. The fair value adjustment was not material in the years ended December 31, 2020 and 2019. ​ In conjunction with entering into the first amendment to the 2019 Credit Facility, on July 15, 2020, the Company issued a warrant to SVB to purchase 21,500 shares of the Company’s common stock at an exercise price of $0.01 per share. The warrant expires on July 15, 2025. The warrant is classified as equity and was recorded as a debt discount that will be amortized to interest expense using the effective interest method. The fair value of the warrant was $152,000 on the date of issuance using the Black-Scholes option-pricing model. ​ In connection with the Company’s prior credit facility with Ares Venture Finance entered into in June 2015, the Company issued Ares Venture Finance a warrant to purchase 18,461 shares of the Company’s common stock at an exercise price of $26.00 per share. The warrant can be exercised at any time and expires on June 5, 2025.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Stock-Based Compensation
Stock-Based Compensation	8. Stock-Based Compensation 2016 Employee Incentive Plan The Company’s board of directors adopted the 2016 Equity Incentive Plan (the 2016 Plan) on April 25, 2016, which was subsequently approved on September 20, 2016 by the Company’s stockholders. The 2016 Plan became effective on October 7, 2016, the date the Company’s S-8 registration statement relating to the 2016 Plan was declared effective by the SEC. The Company’s 2016 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based stock awards, and other forms of equity compensation to employees, directors and consultants. In addition, the Company’s 2016 Plan provides for the grant of performance cash awards to employees, directors and consultants. The maximum number of shares of common stock that may be issued under the Company’s 2016 Plan is 500,000 subject to an automatic increase on January 1 of each year, beginning on January 1, 2017, and continuing through and including January 1, 2026, by 3% of the total number of shares of capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company’s board of directors. 2008 Employee Incentive Plan The 2008 Equity Incentive Plan (the 2008 Plan) provided for the issuance of incentive stock options (ISO), nonqualified stock options, and other stock compensation awards. Under the terms of the 2008 Plan, the exercise price of an ISO shall be not less than 100% of the fair value of the stock at the date of grant, as determined by the board of directors, or in the case of certain ISOs, at 110% of the fair market value at the date of grant. The term and vesting periods for options granted under the 2008 Plan were determined by the Company’s board of directors. Options granted generally vest over four years. Options must be exercised within a 10-year No Summary of Stock Option Activity The following table summarizes the stock option and award activity for all grants under the 2008 Plan and 2016 Plan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ ​ ​ ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ ​ Options and ​ ​ ​ Average ​ Average ​ ​ ​ ​ ​ Awards ​ ​ ​ Exercise ​ Remaining ​ Aggregate ​ ​ Available for ​ Number of ​ Price Per ​ Contractual ​ Intrinsic ​ ​ Grant Options Share Life (years) Value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) Balance—December 31, 2019 638,227 1,931,903 ​ $ 7.17 ​ 6.5 ​ $ 188 Authorized 542,452 ​ — ​ ​ ​ ​ ​ ​ ​ ​ RSUs granted ​ (469,304) ​ — ​ ​ ​ ​ ​ ​ ​ ​ RSUs cancelled/forfeited ​ 56,562 ​ — ​ ​ ​ ​ ​ ​ ​ ​ Options granted ​ (894,955) ​ 894,955 ​ $ 2.74 ​ ​ ​ ​ ​ Options exercised — ​ (223,463) ​ $ 5.23 ​ ​ ​ $ 355 Options cancelled/forfeited 306,237 ​ (330,490) ​ $ 7.45 ​ ​ ​ ​ ​ Balance—December 31, 2020 179,219 2,272,905 ​ $ 5.58 7.9 ​ $ 1,640 Options exercisable—December 31, 2020 ​ 1,048,021 ​ $ 7.28 ​ 6.8 ​ $ 13 ​ During the years ended December 31, 2020 and 2019, the Company granted options with a weighted-average grant date fair value of $1.81 and $4.06 per share, respectively. The total fair value of options vested during the year was $2.2 million and $2.3 million, for the years ended December 31, 2020, and 2019, respectively. 2016 Employee Stock Purchase Plan The Company’s board of directors adopted the 2016 Employee Stock Purchase Plan (the ESPP) on April 25, 2016, which was subsequently approved on September 20, 2016 by the Company’s stockholders. The Company had 526,863 shares available for issuance under the Company’s ESPP as of December 31, 2020. Employees purchased 49,951 shares for $112,000 during the year ended December 31, 2020 and 44,344 shares for $232,000 during the year ended December 31, 2019. The following table summarizes the assumptions used in the Black-Scholes option-pricing model to determine fair value of the Company’s common shares issued under the ESPP: ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ 2020 2019 Expected volatility 44.7 - 100.7 % 39.6 - 74.2 % Risk-free interest rate 0.12 - 1.68 % 1.67 - 2.66 % Expected term (in years) 0.5 - 1.0 0.5 - 1.0 ​ Dividend yield — % — % ​ Restricted Stock Units In September 2017, the Company’s board of directors authorized the issuance of Restricted Stock Units (RSUs), under the 2016 Plan and adopted a form of Restricted Stock Unit Award Agreement, which is intended to serve as a standard form agreement for RSU grants issued to employees, executive officers, directors and consultants. The fair value of the RSUs is recognized as expense ratably over the vesting period, as determined by the board of directors on the date of grant. The following table summarizes RSU activity for the year ended December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ RSUs Outstanding ​ ​ ​ Weighted- ​ ​ ​ Average ​ ​ Number of Grant Date ​ ​ Restricted Stock Fair Value Per ​ Units Share Balance—December 31, 2019 ​ 211,962 $ 6.97 Granted 469,304 ​ 4.52 Vested ​ (207,962) ​ 6.10 Cancelled/forfeited ​ (56,562) ​ 5.18 Balance—December 31, 2020 416,742 $ 4.89 ​ The fair value of RSUs is determined on the date of grant based on the market price of the Company’s common stock on that date. As of December 31, 2020, there was $1.4 million of unrecognized stock-based compensation expense related to RSUs to be recognized over a weighted-average period of 2.1 years. Stock-based Compensation Expense As of December 31, 2020, there was $3.2 million of total unrecognized compensation expense related to unvested options which is expected to be recognized over a weighted-average period of 2.7 years. Compensation cost capitalized within inventory at December 31, 2020 and 2019 was not material. The Company estimated the fair value of each option grant using the Black-Scholes option-pricing model. The fair value of employee stock options is being amortized on a straight-line basis over the requisite service period of the awards. The fair value of employee stock options was estimated using the assumptions below. ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ 2020 2019 Expected volatility 74.4 - 79.3 % 65.1 - 74.4 % Risk-free interest rate 0.22 - 1.63 % 1.46 - 2.52 % Expected term (in years) 6.07 - 6.08 5.3 - 6.1 ​ Dividend yield — % — % ​

401 (k) Plan

401 (k) Plan	12 Months Ended
	Dec. 31, 2020
401 (k) Plan
401 (k) Plan	9. 401(k) Plan The Company has a defined contribution employee benefit plan pursuant to Section 401(k) of the Internal Revenue Code. The plan allows eligible employees to defer a portion of their annual compensation up to certain statutory limits. At the election of the Board of Directors, the Company may elect to match employee contributions but has not done so to date.

Significant Agreements

Significant Agreements	12 Months Ended
	Dec. 31, 2020
Significant Agreements
Significant Agreements	10. Significant Agreements GLOBALFOUNDRIES, Inc. Joint Development Agreement Since October 17, 2014, the Company has participated in a joint development agreement (JDA) with GLOBALFOUNDRIES Inc. (GF), a semiconductor foundry, for the joint development of Spin-transfer Torque MRAM (STT-MRAM) technology to produce a family of discrete and embedded MRAM technologies. The term of the agreement is until the completion, termination, or expiration of the last statement of work entered into pursuant to the joint development agreement. The agreement was extended on December 31, 2019 to include a new phase of support for 12nm MRAM development. Under the current JDA extension terms, each party licenses its relevant intellectual property to the other party. For certain jointly developed works, the parties have agreed to follow an invention allocation procedure to determine ownership. In addition, GF possesses the exclusive right to manufacture the Company’s discrete and embedded STT-MRAM devices developed pursuant to the agreement until the earlier of three years after the qualification of the MRAM device for a particular technology node or four years after the completion of the relevant statement of work under which the device was developed. For the same exclusivity period associated with the relevant device, GF agreed not to license intellectual property developed in connection with the JDA to named competitors of the Company. Generally, unless otherwise specified in the agreement or a statement of work, the Company and GF share project costs, which do not include personnel or production qualification costs, under the JDA. If GF manufactures, sells or transfers to customers wafers containing production quantified STT-MRAM devices that utilize certain design information, GF will be required to pay the Company a royalty. The Company incurred no Silterra Malaysia Sdn. Bhd. Joint Collaboration Agreement In September 2018, the Company entered into a Joint Collaboration Agreement (JCA) with Silterra Malaysia Sdn. Bhd., and another third party. The JCA was intended to create additional manufacturing capacity for the Company’s Toggle MRAM products. The Company had previously anticipated initial production starting in 2020. However, as a result of recent delays, the Company now anticipates that initial production is expected to start some time in 2021. Under the JCA, the Company is required to pay non-recurring engineering costs of $1.0 million. As of December 31, 2020, the Company has paid $600,000 of these JCA costs. There were no JCA costs paid during the year ended December 31, 2020. The Company paid $200,000 of JCA costs in the year ended December 31, 2019.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2020
Restructuring
Restructuring	11. Restructuring During the year ended December 31, 2019, the Company implemented a corporate restructuring to ensure long-term sustainability. As part of the restructuring, the Company reduced its workforce by approximately 15 positions across all functions. The restructuring expense of $782,000 during the year ended December 31, 2019 represented all cash consideration of the restructuring, and primarily related to employee severance and benefit arrangements that was paid in 2020. ​

Geographic Information

Geographic Information	12 Months Ended
	Dec. 31, 2020
Geographic Information
Geographic Information	12. Geographic Information Property and equipment, net by country was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 2019 United States ​ $ 1,415 ​ $ 2,235 Singapore ​ ​ 287 ​ ​ 789 Other ​ ​ 244 ​ ​ 455 ​ ​ $ 1,946 ​ $ 3,479 ​ Revenue from customers is designated based on the geographic region or country to which the product is delivered or the licensee is located. Revenue by country was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Hong Kong ​ $ 18,258 ​ $ 10,144 United States ​ ​ 5,743 ​ ​ 4,915 Japan ​ ​ 5,403 ​ ​ 5,660 Canada ​ ​ 3,423 ​ ​ 1,714 Germany ​ ​ 2,867 ​ ​ 6,423 China ​ ​ 2,403 ​ ​ 1,361 All other ​ ​ 3,934 ​ ​ 7,286 Total revenue ​ $ 42,031 ​ $ 37,503 ​

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Taxes
Income Taxes	13. Income Taxes For the years ended December 31, 2020 and 2019, the Company’s provision for income tax consisted of: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Current: ​ ​ ​ ​ ​ ​ Federal ​ ​ — ​ ​ — State ​ ​ — ​ ​ — Foreign ​ ​ 260 ​ ​ — Total Current ​ $ 260 ​ $ — ​ ​ ​ ​ ​ ​ ​ Deferred: ​ ​ ​ ​ ​ ​ Federal ​ ​ — ​ ​ — State ​ ​ — ​ ​ — Foreign ​ ​ — ​ ​ — Total Deferred ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ Provision for income taxes ​ $ 260 ​ $ — ​ The reconciliation of the statutory federal income tax rate to the Company’s effective tax rate is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Tax at statutory federal rate ​ (21.0) % (21.0) % State taxes, net of federal benefit ​ (1.5) ​ (0.8) ​ Stock-based compensation ​ 5.4 ​ 2.0 ​ Change in uncertain tax benefits ​ 3.1 ​ — ​ Change in valuation allowance ​ 17.0 ​ 18.9 ​ Other ​ — ​ 0.9 ​ Provision for income taxes ​ 3.0 % 0.0 % ​ The tax effects of temporary differences and carryforwards that give rise to significant portions of the deferred tax assets are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Deferred tax assets: ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 31,683 ​ $ 29,684 Inventory ​ ​ 147 ​ ​ 874 Accruals ​ ​ 254 ​ ​ 430 Depreciation and amortization ​ ​ 240 ​ ​ 143 Limitation on business interest ​ ​ 268 ​ ​ 186 Stock-based compensation ​ ​ 676 ​ ​ 546 Right of use liability ​ ​ 549 ​ ​ 776 Gross deferred tax assets ​ ​ 33,817 ​ ​ 32,639 Valuation allowance ​ ​ (33,265) ​ ​ (31,840) Deferred tax assets ​ ​ 552 ​ ​ 799 Deferred tax liabilities: ​ ​ ​ ​ ​ ​ Right of use asset ​ ​ (527) ​ ​ (710) Other ​ ​ (25) ​ ​ (89) Deferred tax liabilities ​ ​ (552) ​ ​ (799) Net deferred tax assets ​ $ — ​ $ — ​ The Company is required to reduce its deferred tax assets by a valuation allowance if it is more likely than not that some or all of its deferred tax assets will not be realized. Management must use judgment in assessing the potential need for a valuation allowance, which requires an evaluation of both negative and positive evidence. The weight given to the potential effect of negative and positive evidence should be commensurate with the extent to which it can be objectively verified. In determining the need for and amount of the valuation allowance, if any, the Company assesses the likelihood that it will be able to recover its deferred tax assets using historical levels of income, estimates of future income and tax planning strategies. As a result of historical cumulative losses, the Company determined that, based on all available evidence, there was substantial uncertainty as to whether it will recover recorded net deferred taxes in future periods. Accordingly, the Company recorded a valuation allowance against all of its net deferred tax assets as of December 31, 2020 and 2019. There was no utilization in 2020 and the net valuation allowance increased by $1.4 million in 2020. In 2019 there was no utilization and the net valuation allowance increased by $2.8 million in 2019. As of December 31, 2020, the Company had federal net operating loss carryforwards of approximately $140.5 million, of which $99.7 million will begin to expire in the year of 2028 through 2037 if not utilized, and $40.8 million will carryover indefinitely. In addition, the Company had state net operating loss carryforwards of approximately $54.1 million, of which $51.5 million will begin to expire in 2023 through 2040 if not utilized, and $2.6 million will carryover indefinitely. The Tax Reform Act of 1986 (the Act) provides for a limitation on the annual use of net operating loss and research and development tax credit carryforwards following certain ownership changes (as defined by the Act and codified under IRC Section 382) that could limit the Company’s ability to utilize these carryforwards. Should the limitation apply, the related net operating loss deferred tax asset and the valuation allowance would be reduced by the same amount. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was enacted into law. The legislation contains a number of economic relief provisions in response to the COVID-19 pandemic, including the following tax related provisions; (1) ability to carryback tax losses five years for losses generated in tax year 2018 through 2020, (2) the ability for Corporations to elect to utilize the 2019 Adjusted Taxable Income and 50% limitation for IRC Section 163(j) purposes, (3) a technical correction to the definition of Qualified Leasehold Improvement Property, and (4) the ability to defer employer payroll taxes for the period of March 27 to December 31, 2020. As of December 31, 2020, these provisions do not materially impact the Company. ​ The Company files income tax returns in the U.S. federal and various state jurisdictions. The Company is subject to U.S. federal and state income tax examinations by authorities for all tax years beginning in 2008, due to the accumulated net operating losses that are carried forward. A summary of changes in the Company’s gross unrecognized tax benefits for the years ended December 31, 2020 and 2019 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Unrecognized tax expense, beginning of the year ​ ​ — ​ ​ — Increase related to prior year tax positions ​ ​ 91 ​ ​ — Increase related to current year tax positions ​ ​ 13 ​ ​ — Unrecognized tax expense, end of year ​ $ 104 ​ $ — ​ The total balance of unrecognized tax benefits as of December 31, 2020 would impact the effective tax rate, if recognized. ​ The Company’s policy is to recognize interest and penalties accrued on any unrecognized tax benefit as a component of income tax expense. The Company has accrued penalties and interest of $156,000 and $0, as of December 31, 2020 and 2019, respectively. The Company estimates no material amount of unrecognized tax benefits will be recognized in the next 12 months.

Net Loss Per Common Share

Net Loss Per Common Share	12 Months Ended
	Dec. 31, 2020
Net Loss Per Common Share
Net Loss Per Common Share	14. Net Loss Per Common Share The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Numerator: ​ ​ Net loss ​ $ (8,512) ​ $ (14,669) Denominator: ​ ​ Weighted-average common shares outstanding used to calculate net loss per common share, basic and diluted ​ 18,782,287 ​ 17,317,042 Net loss per common share, basic and diluted ​ $ (0.45) ​ $ (0.85) ​ The following outstanding shares of potentially dilutive securities have been excluded from diluted net loss per common share for the periods presented, because their inclusion would be anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2020 2019 Options to purchase common stock ​ 2,272,905 1,931,903 Restricted stock units ​ 416,742 ​ 211,962 ​ Common stock warrants ​ 49,336 27,836 Total ​ 2,738,983 2,171,701 ​

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Use of Estimates	Use of Estimates The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP). The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, fair value of assets and liabilities, inventory, product warranty reserves, income taxes, and stock-based compensation. The Company believes its estimates and assumptions are reasonable; however, actual results may differ from the Company’s estimates.
Segments	Segments The Company’s chief operating decision maker is its Chief Executive Officer who reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance for the entire Company. As a result, the Company has single operating and reportable segment.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid, short-term investments with maturity dates of 90 days or less at the date of purchase to be cash equivalents. The Company’s cash equivalents consist solely of money market funds.
Accounts receivable, net	Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. The Company generally does not require collateral or other security in support of accounts receivable. Allowances would be provided for individual accounts receivable when the Company becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy, deterioration in the customer’s operating results or change in financial position. If circumstances related to customers change, estimates of the recoverability of receivables would be further adjusted. The Company also considers a number of factors in evaluating the sufficiency of its allowance for doubtful accounts, including the length of time receivables are past due, significant one-time events, creditworthiness of customers and historical experience. Account balances would be charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The Company’s evaluation determined that no material allowance for doubtful accounts was necessary at December 31, 2020 and 2019. The Company establishes an allowance for product returns. The Company analyzes historical returns, current economic trends and changes in customer demand and acceptance of products when evaluating the adequacy of sales returns. Returns are processed as credits on future purchases and, as a result, the allowance is recorded against the balance of trade accounts receivable. In addition, the Company establishes an allowance for estimated price concessions related to its distributer agreements. The Company estimates credits to distributors based on the historical rate of credits provided to distributors relative to sales. At December 31, 2020 and 2019, the allowance for product returns and price concessions was $238,000 and $231,000, respectively. Accounts receivable, net consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 ​ 2019 Trade accounts receivable ​ $ 7,590 ​ $ 5,454 Unbilled accounts receivable ​ ​ 255 ​ ​ 576 Allowance for product returns and price concessions ​ (238) ​ (231) Accounts receivable, net ​ $ 7,607 ​ $ 5,799 ​
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially expose the Company to a concentration of credit risk consist principally of cash and cash equivalents that are held by a financial institution in the United States and accounts receivable. Amounts on deposit with a financial institution may at times exceed federally insured limits. The Company maintains its cash accounts with high credit quality financial institutions and accordingly, minimal credit risk exists with respect to the financial institutions. Significant customers are those which represent more than 10% of the Company’s total revenue or net accounts receivable balance at each respective balance sheet date. For the purposes of this disclosure, the Company defines “customer” as the entity that is purchasing the products or licenses directly from the Company, which includes the distributors of the Company’s products in addition to end customers that the Company sells to directly. For each significant customer, revenue as a percentage of total revenue and accounts receivable as a percentage of total accounts receivable, net are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ Accounts Receivable ​ ​ Year Ended December 31, ​ December 31, Customers ​ 2020 2019 2020 2019 Celestica Shared Service Centre ​ 29 % 21 % 29 % 41 % Customer B ​ 11 % * ​ 25 % 11 % Customer C ​ * ​ 12 % * ​ * ​ Customer D ​ * ​ 12 % * ​ * ​ Customer E ​ * ​ 10 % * ​ * ​ * Less than 10%
Inventory	Inventory Inventory is valued at the lower of cost, using the first-in, first-out or specific identification method, or market. The carrying value of inventory is adjusted for excess and obsolescence based on the Company’s evaluation which takes into consideration historical and expected future demand, the effect new products may have on the sale of existing products, technological obsolescence, and other factors including inventory age and shipment. At the point of loss recognition, a new lower cost basis for that inventory is established and subsequent changes in facts and circumstances do not result in the restoration or increase in that new cost basis.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as an exit price, representing the amount that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants. The framework for measuring fair value provides a three-tier hierarchy prioritizing inputs to valuation techniques used in measuring fair value as follows: Level 1 Level 2 Level 3 The carrying value of accounts receivable, accounts payable, and other accruals readily convertible into cash approximate fair value because of the short-term nature of the instruments. As of December 31, 2020, based on Level 2 inputs and the borrowing rates available to the Company for loans with similar terms and consideration of the Company’s credit risk, the carrying value of the Company’s variable interest rate debt, excluding unamortized debt issuance costs, approximates fair value. The Company’s financial instruments consist of Level 1 assets and a Level 3 liability. Where quoted prices are available in an active market, securities are classified as Level 1. Level 1 assets consist of highly liquid money market funds that are included in cash equivalents. The Company’s Level 3 liability consists of warrants issued in connection with the 2019 Credit Facility (Note 6). The change in the fair value of the warrant liability during the year ended December 31, 2020 was immaterial. The following tables sets forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 14,669 $ — $ — $ 14,669 Total assets measured at fair value ​ $ 14,669 $ — $ — $ 14,669 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant liability ​ $ — $ — $ 31 $ 31 Total liabilities measured at fair value ​ $ — $ — $ 31 $ 31 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 12,367 $ — $ — $ 12,367 Total assets measured at fair value ​ $ 12,367 $ — $ — $ 12,367 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant liability ​ $ — $ — $ 33 $ 33 Total liabilities measured at fair value ​ $ — $ — $ 33 $ 33
Property and Equipment	Property and Equipment Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation begins at the time the asset is placed in service. Maintenance and repairs are charged to operations as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives of the assets: ​ ​ ​ ​ ​ Useful Lives Computer and network equipment ​ 2 years Manufacturing equipment ​ 2 – 7 years Furniture and fixtures ​ 7 years Software ​ 3 years Leasehold improvements ​ 2 years (not to exceed the lease life) ​ Costs incurred to develop software for internal use during the application development phase are capitalized and amortized over such software’s estimated useful life. Costs related to the design or maintenance of internal-use software are included in operating expenses as incurred. During 2020, no
Impairment of Long-lived Assets	Impairment of Long-lived Assets The Company evaluates its long-lived assets, including property and equipment, at the asset group level, for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. If such events or changes in circumstances occur, for purposes of this assessment, long-lived assets are grouped with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability of these assets is measured by comparison of the carrying amount of each asset group to the future undiscounted cash flows the asset group is expected to generate over its remaining life. If the asset group is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. There have been no impairments of the Company’s long-lived assets during either of the periods presented.
Leases	Leases The Company leases office, lab, manufacturing space and equipment in various locations with initial lease terms of up to five years. These leases require monthly lease payments that may renewal options renew extend two The Company determines if an arrangement is a lease at inception. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. The classification of the Company's leases as operating or finance leases along with the initial measurement and recognition of the associated ROU assets and lease liabilities is performed at the lease commencement date. The measurement of lease liabilities is based on the present value of future lease payments over the lease term. The Company uses its incremental borrowing rate, based on the information available at commencement date, to determine the present value of lease payments when its leases do not provide an implicit rate. The Company uses the implicit rate when readily determinable. The ROU asset is based on the measurement of the lease liability, includes any lease payments made prior to or on lease commencement and excludes lease incentives and initial direct costs incurred, as applicable. Lease expense for the Company’s operating leases is recognized on a straight-line basis over the lease term. Amortization expense for ROU assets associated with finance leases is recognized on a straight-line basis over the shorter of the useful life of the asset or the lease term and interest expense associated with finance leases is recognized on the balance of the lease liability using the effective interest method based on the estimated incremental borrowing rate. The Company has lease agreements with lease and non-lease components. The Company has elected to not separate lease and non-lease components for any leases involving real estate and office equipment classes of assets and, as a result, accounts for the lease and non-lease components as a single lease component. The Company has elected to separate lease and non-lease components for any leases involving manufacturing facility classes of assets. Further, the Company elected the short-term lease exception policy, permitting it to not apply the recognition requirements of this standard to leases with terms of 12 months or less (short-term leases) for all classes of assets. As of December 31, 2020, the Company did not have any short-term leases. Operating leases are included in right-of-use assets, operating lease liabilities, and operating lease liabilities, net of current portion in the Company’s balance sheet. Finance leases are included in property and equipment, net, other liabilities, and other long-term liabilities in the Company’s balance sheet.
Debt Issuance Costs	Debt Issuance Costs The Company defers and amortizes issuance costs, underwriting fees, end of term payments, and related expenses incurred in connection with the issuance of debt instruments using the effective interest method over the terms of the respective instruments. Debt issuance costs are reflected as a direct reduction of the carrying amount of the related debt liability.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when a customer obtains control of the promised products or services, in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. Revenue is recognized net of allowances for returns and price concessions, and any taxes collected from customers, which are subsequently remitted to governmental authorities. Nature of Products and Services The Company’s revenue is derived from the sale of MRAM-based products in discrete unit form, licenses of and royalties on its MRAM and magnetic sensor technology, the sale of backend foundry services and design services to third parties. Sales of products in discrete unit form are recognized at a point in time, revenue related to licensing agreements is recognized when the Company has delivered control of the technology, revenue related to royalty agreements is recognized in the period in which sales generated from products sold using the Company’s technology occurs, sales of backend foundry services are recognized over time, and design services to third parties are recognized either at a point in time or over time, depending on the nature of the services. Product Revenue For products sold in their discrete form, the Company either sells its products directly to original equipment manufacturers (OEMs), original design manufacturers (ODMs) and contract manufacturers (CMs), or through a network of distributors, who in turn sell to those customers. For sales directly to OEMs, ODMs and CMs, revenue is recognized when the OEM, ODM or CM obtains control of the product, which occurs at a point in time, generally upon shipment to the customer. The Company sells the majority of its products to its distributors at a uniform list price. However, distributors may resell the Company’s products to end customers at a very broad range of individually negotiated price points. Distributors are provided with price concessions subsequent to the delivery of product to them and such amounts are dependent on the end customer and product sales price. The price concessions are based on a variety of factors, including customer, product, quantity, geography and competitive differentiation. Price protection rights grant distributors the right to a credit in the event of declines in the price of the Company’s products. Under these circumstances, the Company remits back to the distributor a portion of their original purchase price after the resale transaction is completed in the form of a credit against the distributors’ outstanding accounts receivable balance. The credits are on a per unit basis and are not given to the distributor until the distributor provides information regarding the sale to their end customer. The Company estimates these credits and records such estimates in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of an allowance for price concessions due to distributors. The Company estimates credits to distributors based on the historical rate of credits provided to distributors relative to sales. Revenue on shipments to distributors is recorded when control of the products has been transferred to the distributor. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company estimates its product return liability by analyzing its historical returns, current economic trends and changes in customer demand and acceptance of products. The Company has received insignificant returns to date and believes that returns of its products will continue to be minimal. Upon the transfer of control, generally at shipment, the Company records a trade receivable for the selling price as there is a legally enforceable obligation of the distributor to pay for the product delivered, an allowance is recorded for the estimated discount that will be provided to the distributor, and the net of these amounts is recorded as revenue on the statement of operations. License Revenue For licenses of technology, recognition of revenue is dependent upon whether the Company has delivered rights to the technology, and whether there are future performance obligations under the contract. In some instances, the license agreements call for future events or activities to occur in order for milestones amounts to become due from the customer. The terms of such agreements include payment to the Company of one or more of the following: non-refundable upfront fees; and royalties on net sales of licensed products. Historically, these license agreements have not included other future performance obligations for the Company once the license has been transferred to the customer. Revenue from non-refundable upfront payments is recognized when the license is transferred to the customer and the Company has no other performance obligations. Royalties Revenue from sales-based royalties from licenses of the Company’s technology are recognized at the later of when (1) the sale occurs or (2) the performance obligation to which some or all of the sales-based royalty has been allocated is satisfied (in whole or in part). The Company will record an unbilled receivable (within accounts receivable, net) for the portion of sales-based royalties that have been earned, but not invoiced at the end of each reporting period. Other Revenue For certain revenue streams, the Company recognizes revenue based on the pattern of transfer of the services. The Company uses the input method of measuring costs incurred to date compared to total estimated costs to be incurred under the contract as this method most faithfully depicts its performance. The Company will record an unbilled receivable (within accounts receivable, net) for the portion of the work that has been completed but not invoiced at the end of each reporting period. At the inception of each agreement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price by using the most likely amount method. If it is probable that a significant reversal of cumulative revenue would not occur, the associated milestone value is included in the transaction price. At the end of each subsequent reporting period, the Company re-evaluates the probability or achievement of each such milestone and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment.
Product Warranty	Product Warranty The Company generally sells products with a limited warranty of product quality and a limited indemnification of customers against intellectual property infringement claims related to the Company’s products. The Company accrues for known warranty and indemnification issues if a loss is probable and can be reasonably estimated, and accrues for estimated losses incurred for unidentified issues based on historical experience. A warranty liability was not recorded at December 31, 2020 and 2019, as the estimated future warranty costs were not material based on the Company’s historical experience.
Research and Development	Research and Development Research and development expenses are incurred in support of internal development programs or as part of the Company’s joint development agreement with GLOBALFOUNDRIES and joint collaboration agreement with Silterra Malaysia Sdn. Bhd. (see Note 10). Research and development expenses include personnel-related costs (including stock-based compensation), circuit design costs, purchases of materials and laboratory supplies, fabrication and packaging of experimental integrated circuit products, depreciation of research and development related capital equipment and overhead, and are expensed as incurred.
Stock-based Compensation	Stock-based Compensation Stock-based compensation arrangements include stock option grants and restricted stock unit (RSU) awards under the Company’s equity incentive plans, as well as shares issued under the Company’s Employee Stock Purchase Plan (ESPP), through which employees may purchase the Company’s common stock at a discount to the market price. The Company measures its stock option grants based on the estimated fair value of the options as of the grant date using the Black-Scholes option-pricing model. Stock-based compensation expense is recognized over the requisite service period using the straight-line method. The Company accounts for forfeitures as they occur. Expected volatility. Risk-free interest rate. Expected term. Dividend yield.
Income Taxes	Income Taxes The Company uses the liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company must then assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit.
Net Loss per Common Share	Net Loss per Common Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding for the period less shares subject to repurchase, without consideration of potentially dilutive securities. Diluted net loss per common share is the same as basic net loss per common share since the effect of potentially dilutive securities is anti-dilutive.
Recently Issued Pronouncements	Recently Issued Pronouncements In December 2019, the FASB issued Accounting Standards Update (ASU) 2019-12, Income Taxes (Topic 740). Simplifying the Accounting for Income Taxes. The new guidance eliminates certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, and the recognition of deferred tax liabilities for outside basis differences. It also clarifies and simplifies other aspects of the accounting for income taxes. ASU 2019-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption is permitted. The adoption of ASU 2019-12 is not expected to have a material effect on the Company’s financial statements and related disclosures. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which amends the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. As the Company is a smaller reporting company, ASU 2016-13 is effective for annual reporting periods, and interim periods within those years, beginning after December 15, 2022, and requires a cumulative effect adjustment to the balance sheet as of the beginning of the first reporting period in which the guidance is effective. In April 2019, the FASB issued ASU No. 2019-04, Codification Improvements Financial Instruments-Credit Losses (Topic 326). The new ASU provides narrow-scope amendments to help apply ASU No. 2016-13. The Company is evaluating the impact of the adoption of ASU 2016-13 on its financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Schedule of accounts receivable net	Accounts receivable, net consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 ​ 2019 Trade accounts receivable ​ $ 7,590 ​ $ 5,454 Unbilled accounts receivable ​ ​ 255 ​ ​ 576 Allowance for product returns and price concessions ​ (238) ​ (231) Accounts receivable, net ​ $ 7,607 ​ $ 5,799
Schedule of revenue and accounts receivable for each significant customer	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue ​ Accounts Receivable ​ ​ Year Ended December 31, ​ December 31, Customers ​ 2020 2019 2020 2019 Celestica Shared Service Centre ​ 29 % 21 % 29 % 41 % Customer B ​ 11 % * ​ 25 % 11 % Customer C ​ * ​ 12 % * ​ * ​ Customer D ​ * ​ 12 % * ​ * ​ Customer E ​ * ​ 10 % * ​ * ​ * Less than 10%
Schedule of fair value of financial assets and liabilities measured on recurring basis	The following tables sets forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 14,669 $ — $ — $ 14,669 Total assets measured at fair value ​ $ 14,669 $ — $ — $ 14,669 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant liability ​ $ — $ — $ 31 $ 31 Total liabilities measured at fair value ​ $ — $ — $ 31 $ 31 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 12,367 $ — $ — $ 12,367 Total assets measured at fair value ​ $ 12,367 $ — $ — $ 12,367 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant liability ​ $ — $ — $ 33 $ 33 Total liabilities measured at fair value ​ $ — $ — $ 33 $ 33
Schedule of estimated useful lives of the assets	​ ​ ​ ​ ​ Useful Lives Computer and network equipment ​ 2 years Manufacturing equipment ​ 2 – 7 years Furniture and fixtures ​ 7 years Software ​ 3 years Leasehold improvements ​ 2 years (not to exceed the lease life)

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue.
Schedule of disaggregation of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ Distributor ​ $ 26,027 ​ $ 24,724 ​ Non-distributor ​ ​ 16,004 ​ ​ 12,779 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​ ​ ​ ​ The following table presents the Company’s revenues disaggregated by timing of recognition (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ Point in time ​ $ 40,846 ​ $ 35,665 ​ Over time ​ ​ 1,185 ​ ​ 1,838 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​ ​ ​ The following table presents the Company’s revenues disaggregated by type (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ Product sales ​ $ 39,848 ​ $ 34,595 ​ Royalties ​ ​ 998 ​ ​ 1,070 ​ Other revenue ​ ​ 1,185 ​ ​ 1,838 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​ ​ The Company recognizes revenue in three geographic regions: North America; Europe, Middle East and Africa (EMEA); and Asia-Pacific (APAC). The following table presents the Company’s revenues disaggregated by the geographic region to which the product is delivered or licensee is located (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 ​ APAC ​ $ 29,480 ​ $ 20,093 ​ North America ​ ​ 9,253 ​ ​ 8,690 ​ EMEA ​ ​ 3,298 ​ ​ 8,720 ​ Total revenue ​ $ 42,031 ​ $ 37,503 ​

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2020
Balance Sheet Components
Schedule of Inventory	Inventory consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2020 2019 Raw materials ​ $ 329 ​ $ 119 Work-in-process ​ 4,910 ​ 6,329 Finished goods ​ 482 ​ 1,415 Total inventory ​ $ 5,721 ​ $ 7,863
Schedule of property and equipment, net	Property and equipment, net consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Manufacturing equipment ​ $ 12,296 ​ $ 12,228 Computer and network equipment ​ ​ 917 ​ ​ 877 Furniture and fixtures ​ ​ 112 ​ ​ 112 Software ​ ​ 925 ​ ​ 925 Leasehold improvements ​ ​ 1,444 ​ ​ 1,444 Total property and equipment, gross ​ ​ 15,694 ​ ​ 15,586 Less: accumulated depreciation ​ ​ (13,748) ​ ​ (12,107) Total property and equipment, net ​ $ 1,946 ​ $ 3,479
Schedule of accrued liabilities	Accrued liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2020 2019 Payroll-related expenses ​ $ 1,274 ​ $ 1,236 Joint development agreement expenses ​ ​ — ​ ​ 170 Inventory ​ ​ 416 ​ ​ 87 Restructuring expenses ​ — ​ 782 Other ​ 542 ​ 452 Total accrued liabilities ​ $ 2,232 ​ $ 2,727

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies
Schedule of operating lease payments	The undiscounted future non-cancellable lease payments under the Company’s operating leases were as follows (in thousands): ​ ​ ​ ​ ​ As of December 31, 2020 Amount ​ 2021 ​ $ 1,603 ​ 2022 ​ ​ 861 ​ 2023 ​ ​ 68 ​ Total undiscounted lease payments ​ ​ 2,532 ​ Less: present value adjustment ​ ​ (121) ​ Total operating lease liabilities ​ ​ 2,411 ​ Less: current portion of operating lease liabilities ​ ​ (1,508) ​ Total operating lease liabilities, net of current portion ​ $ 903 ​ ​
Schedule of supplemental information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Weighted-average remaining lease term (years) 1.74 ​ ​ 2.06 Weighted-average discount rate ​ 6.00 % ​ 6.00 %

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt
Summary of debt	The carrying value of the Company’s 2019 Credit Facility at December 31, 2020, was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current Long-Term ​ ​ ​ ​ Portion ​ Debt ​ Total Credit Facility ​ $ 4,400 ​ $ 4,020 ​ $ 8,420 Unamortized debt discounts ​ (158) ​ (272) ​ (430) Net carrying value ​ $ 4,242 ​ $ 3,748 ​ $ 7,990 ​ The carrying value of the Company’s 2019 Credit Facility at December 31, 2019, was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current Long-Term ​ ​ ​ ​ Portion ​ Debt ​ Total Credit Facility ​ $ 800 ​ $ 7,620 ​ $ 8,420 Unamortized debt discounts ​ ​ (130) ​ (471) ​ (601) Net carrying value ​ $ 670 ​ $ 7,149 ​ $ 7,819
Summary of principal repayments of credit facility	The table below includes the principal repayments due under the 2019 Credit Facility as of December 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Principal Repayment as of December 31, 2020 2021 ​ ​ 4,400 2022 ​ ​ 2,400 2023 ​ ​ 1,620 Total principal repayments ​ $ 8,420

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity
Summary of common stock reserved for future issuance	​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 ​ 2019 Options issued and outstanding 2,272,905 1,931,903 Shares available for future option grants 179,219 638,227 RSUs subject to future vesting ​ 416,742 ​ 211,962 Common stock warrants 49,336 27,836 Total 2,918,202 2,809,928

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ ​ ​ ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ ​ Options and ​ ​ ​ Average ​ Average ​ ​ ​ ​ ​ Awards ​ ​ ​ Exercise ​ Remaining ​ Aggregate ​ ​ Available for ​ Number of ​ Price Per ​ Contractual ​ Intrinsic ​ ​ Grant Options Share Life (years) Value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) Balance—December 31, 2019 638,227 1,931,903 ​ $ 7.17 ​ 6.5 ​ $ 188 Authorized 542,452 ​ — ​ ​ ​ ​ ​ ​ ​ ​ RSUs granted ​ (469,304) ​ — ​ ​ ​ ​ ​ ​ ​ ​ RSUs cancelled/forfeited ​ 56,562 ​ — ​ ​ ​ ​ ​ ​ ​ ​ Options granted ​ (894,955) ​ 894,955 ​ $ 2.74 ​ ​ ​ ​ ​ Options exercised — ​ (223,463) ​ $ 5.23 ​ ​ ​ $ 355 Options cancelled/forfeited 306,237 ​ (330,490) ​ $ 7.45 ​ ​ ​ ​ ​ Balance—December 31, 2020 179,219 2,272,905 ​ $ 5.58 7.9 ​ $ 1,640 Options exercisable—December 31, 2020 ​ 1,048,021 ​ $ 7.28 ​ 6.8 ​ $ 13
Schedule of restricted stock unit activity	​ ​ ​ ​ ​ ​ ​ ​ ​ RSUs Outstanding ​ ​ ​ Weighted- ​ ​ ​ Average ​ ​ Number of Grant Date ​ ​ Restricted Stock Fair Value Per ​ Units Share Balance—December 31, 2019 ​ 211,962 $ 6.97 Granted 469,304 ​ 4.52 Vested ​ (207,962) ​ 6.10 Cancelled/forfeited ​ (56,562) ​ 5.18 Balance—December 31, 2020 416,742 $ 4.89
Employee
Schedule of fair value assumptions	​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ 2020 2019 Expected volatility 74.4 - 79.3 % 65.1 - 74.4 % Risk-free interest rate 0.22 - 1.63 % 1.46 - 2.52 % Expected term (in years) 6.07 - 6.08 5.3 - 6.1 ​ Dividend yield — % — %
2016 Employee Stock Purchase Plan
Schedule of fair value assumptions	​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ 2020 2019 Expected volatility 44.7 - 100.7 % 39.6 - 74.2 % Risk-free interest rate 0.12 - 1.68 % 1.67 - 2.66 % Expected term (in years) 0.5 - 1.0 0.5 - 1.0 ​ Dividend yield — % — %

Geographic Information (Tables)

Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2020
Geographic Information
Schedule of property and equipment by country	Property and equipment, net by country was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 2019 United States ​ $ 1,415 ​ $ 2,235 Singapore ​ ​ 287 ​ ​ 789 Other ​ ​ 244 ​ ​ 455 ​ ​ $ 1,946 ​ $ 3,479
Schedule of revenue by country	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Hong Kong ​ $ 18,258 ​ $ 10,144 United States ​ ​ 5,743 ​ ​ 4,915 Japan ​ ​ 5,403 ​ ​ 5,660 Canada ​ ​ 3,423 ​ ​ 1,714 Germany ​ ​ 2,867 ​ ​ 6,423 China ​ ​ 2,403 ​ ​ 1,361 All other ​ ​ 3,934 ​ ​ 7,286 Total revenue ​ $ 42,031 ​ $ 37,503

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Taxes
Schedule of components of income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Current: ​ ​ ​ ​ ​ ​ Federal ​ ​ — ​ ​ — State ​ ​ — ​ ​ — Foreign ​ ​ 260 ​ ​ — Total Current ​ $ 260 ​ $ — ​ ​ ​ ​ ​ ​ ​ Deferred: ​ ​ ​ ​ ​ ​ Federal ​ ​ — ​ ​ — State ​ ​ — ​ ​ — Foreign ​ ​ — ​ ​ — Total Deferred ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ Provision for income taxes ​ $ 260 ​ $ —
Schedule of reconciliation of statutory federal income tax rate	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Tax at statutory federal rate ​ (21.0) % (21.0) % State taxes, net of federal benefit ​ (1.5) ​ (0.8) ​ Stock-based compensation ​ 5.4 ​ 2.0 ​ Change in uncertain tax benefits ​ 3.1 ​ — ​ Change in valuation allowance ​ 17.0 ​ 18.9 ​ Other ​ — ​ 0.9 ​ Provision for income taxes ​ 3.0 % 0.0 %
Schedule of tax effects of temporary differences and carryforwards	The tax effects of temporary differences and carryforwards that give rise to significant portions of the deferred tax assets are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Deferred tax assets: ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 31,683 ​ $ 29,684 Inventory ​ ​ 147 ​ ​ 874 Accruals ​ ​ 254 ​ ​ 430 Depreciation and amortization ​ ​ 240 ​ ​ 143 Limitation on business interest ​ ​ 268 ​ ​ 186 Stock-based compensation ​ ​ 676 ​ ​ 546 Right of use liability ​ ​ 549 ​ ​ 776 Gross deferred tax assets ​ ​ 33,817 ​ ​ 32,639 Valuation allowance ​ ​ (33,265) ​ ​ (31,840) Deferred tax assets ​ ​ 552 ​ ​ 799 Deferred tax liabilities: ​ ​ ​ ​ ​ ​ Right of use asset ​ ​ (527) ​ ​ (710) Other ​ ​ (25) ​ ​ (89) Deferred tax liabilities ​ ​ (552) ​ ​ (799) Net deferred tax assets ​ $ — ​ $ —
Schedule of changes in the Company's gross unrecognized tax benefits	A summary of changes in the Company’s gross unrecognized tax benefits for the years ended December 31, 2020 and 2019 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Unrecognized tax expense, beginning of the year ​ ​ — ​ ​ — Increase related to prior year tax positions ​ ​ 91 ​ ​ — Increase related to current year tax positions ​ ​ 13 ​ ​ — Unrecognized tax expense, end of year ​ $ 104 ​ $ —

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2020
Net Loss Per Common Share
Computation of basic and diluted net loss per share	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Numerator: ​ ​ Net loss ​ $ (8,512) ​ $ (14,669) Denominator: ​ ​ Weighted-average common shares outstanding used to calculate net loss per common share, basic and diluted ​ 18,782,287 ​ 17,317,042 Net loss per common share, basic and diluted ​ $ (0.45) ​ $ (0.85)
Schedule of potentially dilutive securities excluded from diluted net loss per common share	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2020 2019 Options to purchase common stock ​ 2,272,905 1,931,903 Restricted stock units ​ 416,742 ​ 211,962 ​ Common stock warrants ​ 49,336 27,836 Total ​ 2,738,983 2,171,701

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts receivable
Trade accounts receivable	$ 7,590	$ 5,454
Unbilled accounts receivable	255	576
Allowance for product returns and price concessions	(238)	(231)
Accounts receivable, net	$ 7,607	$ 5,799

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Revenue and Accounts Receivable for Each Significant Customer (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue | Celestica Shared Service Centre
Concentration risk
Concentration risk percentage	29.00%	21.00%
Revenue | Customer B
Concentration risk
Concentration risk percentage	11.00%
Revenue | Customer B | Maximum
Concentration risk
Concentration risk percentage		10.00%
Revenue | Customer C
Concentration risk
Concentration risk percentage		12.00%
Revenue | Customer C | Maximum
Concentration risk
Concentration risk percentage	10.00%
Revenue | Customer D
Concentration risk
Concentration risk percentage		12.00%
Revenue | Customer D | Maximum
Concentration risk
Concentration risk percentage	10.00%
Revenue | Customer E
Concentration risk
Concentration risk percentage		10.00%
Revenue | Customer E | Maximum
Concentration risk
Concentration risk percentage	10.00%
Accounts Receivable | Celestica Shared Service Centre
Concentration risk
Concentration risk percentage	29.00%	41.00%
Accounts Receivable | Customer B
Concentration risk
Concentration risk percentage	25.00%	11.00%
Accounts Receivable | Customer C | Maximum
Concentration risk
Concentration risk percentage	10.00%	10.00%
Accounts Receivable | Customer D | Maximum
Concentration risk
Concentration risk percentage	10.00%	10.00%
Accounts Receivable | Customer E | Maximum
Concentration risk
Concentration risk percentage	10.00%	10.00%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value
Total assets measured at fair value	$ 14,669	$ 12,367
Warrant liability	31	33
Total liabilities measured at fair value	31	33
Level 1
Fair Value
Total assets measured at fair value	14,669	12,367
Level 3
Fair Value
Warrant liability	31	33
Total liabilities measured at fair value	31	33
Money market funds
Fair Value
Money market funds	14,669	12,367
Money market funds | Level 1
Fair Value
Money market funds	$ 14,669	$ 12,367

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property and Equipment, Net
Capitalized software	$ 0	$ 238
Impairment of Long-lived Assets
Impairment of long-lived assets	$ 0	$ 0
Computer and network equipment
Property and Equipment, Net
Useful Lives	2 years
Manufacturing equipment | Minimum
Property and Equipment, Net
Useful Lives	2 years
Manufacturing equipment | Maximum
Property and Equipment, Net
Useful Lives	7 years
Furniture and fixtures
Property and Equipment, Net
Useful Lives	7 years
Software
Property and Equipment, Net
Useful Lives	3 years
Leasehold improvements
Property and Equipment, Net
Useful Lives	2 years

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Leases (Details)	12 Months Ended
	Dec. 31, 2020
Leases
Operating lease - existence of option to extend	true
Finance lease - existence of option to extend	true
Minimum
Leases
Operating lease renewal term (in years)	2 years
Finance lease renewal term (in years)	2 years
Maximum
Leases
Operating term of lease (in years)	5 years
Operating lease renewal term (in years)	5 years
Finance term of lease (in years)	5 years
Finance lease renewal term (in years)	5 years

Revenue - Disaggregated by Sale

Revenue - Disaggregated by Sales Channel (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue
Revenue	$ 42,031	$ 37,503
Distributor
Disaggregation of Revenue
Revenue	26,027	24,724
Non-distributor
Disaggregation of Revenue
Revenue	$ 16,004	$ 12,779

Revenue - Disaggregated by Timi

Revenue - Disaggregated by Timing of Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue
Revenue	$ 42,031	$ 37,503
Point in time
Disaggregation of Revenue
Revenue	40,846	35,665
Over time
Disaggregation of Revenue
Revenue	$ 1,185	$ 1,838

Revenue - Disaggregated by Type

Revenue - Disaggregated by Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue
Revenue	$ 42,031	$ 37,503
Product sales
Disaggregation of Revenue
Revenue	39,848	34,595
Royalties
Disaggregation of Revenue
Revenue	998	1,070
Other revenue
Disaggregation of Revenue
Revenue	$ 1,185	$ 1,838

Revenue - Disaggregated by Geog

Revenue - Disaggregated by Geographic Region (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)region	Dec. 31, 2019USD ($)
Disaggregation of Revenue
Number of primary geographic regions | region	3
Revenue	$ 42,031	$ 37,503
APAC
Disaggregation of Revenue
Revenue	29,480	20,093
North America
Disaggregation of Revenue
Revenue	9,253	8,690
EMEA
Disaggregation of Revenue
Revenue	$ 3,298	$ 8,720

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory
Raw materials	$ 329	$ 119
Work-in-process	4,910	6,329
Finished goods	482	1,415
Total inventory	$ 5,721	$ 7,863

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property and Equipment, Net
Total property and equipment, gross	$ 15,694	$ 15,586
Less: accumulated depreciation	(13,748)	(12,107)
Total property and equipment, net	1,946	3,479
Depreciation and amortization expense	2,000	1,700
Manufacturing equipment
Property and Equipment, Net
Total property and equipment, gross	12,296	12,228
Computer and network equipment
Property and Equipment, Net
Total property and equipment, gross	917	877
Furniture and fixtures
Property and Equipment, Net
Total property and equipment, gross	112	112
Software
Property and Equipment, Net
Total property and equipment, gross	925	925
Leasehold improvements
Property and Equipment, Net
Total property and equipment, gross	$ 1,444	$ 1,444

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued liabilities
Payroll-related expenses	$ 1,274	$ 1,236
Joint development agreement expenses		170
inventory	416	87
Restructuring expenses		782
Other	542	452
Total accrued liabilities	$ 2,232	$ 2,727

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease information
2021	$ 1,603
2022	861
2023	68
Total undiscounted lease payments	2,532
Less: Present value adjustment	(121)
Total operating lease liabilities	2,411
Less: Current portion of operating lease liabilities	(1,508)	$ (1,582)
Total operating lease liabilities, net of current portion	$ 903	$ 1,840
Other lease information
Operating lease weighted-average remaining lease term (years)	1 year 8 months 26 days	2 years 21 days
Operating lease weighted-average discount rate	6.00%	6.00%
Operating lease costs	$ 1,500	$ 1,600

Debt - Credit Facility (Details

Debt - Credit Facility (Details) - USD ($)	Aug. 05, 2019	Jul. 31, 2020	Jun. 30, 2020	Aug. 31, 2019	Dec. 31, 2020	Jul. 15, 2020	Dec. 31, 2019	Jul. 31, 2019
Debt
Common stock, par value					$ 0.0001		$ 0.0001
2017 Credit Facility
Debt
Repayment of credit facility				$ 800,000
Principal amount								$ 8,000,000
2019 Credit Facility
Debt
Number of shares the warrant can be converted to						21,500
Warrant exercise price						$ 0.01
Amount bank could receive if takes the option to put the warrants upon expiration or a liquidity event	$ 50,000
Fair value of warrants						$ 152,000
Principal amount					$ 8,420,000		$ 8,420,000
2019 Credit Facility - Revolving Line Of Credit
Debt
Loan agreement amount		$ 5,000,000
Agreement term		2 years
Effective interest rate					10.18%
Commitment fee (as a percentage)		1.60%
Termination fee (as a percentage)		1.00%
Unused facility fee (as a percentage)		0.125%
Debt amount		$ 2,000,000
Remaining availability					$ 3,000,000
Outstanding balance					$ 2,000,000
2019 Credit Facility - Revolving Line Of Credit | Minimum
Debt
Effective interest rate		4.75%	6.75%		4.75%
2019 Credit Facility - Revolving Line Of Credit | Prime Rate
Debt
Interest rate, basis spread percentage		1.50%
2019 Credit Facility - Revolving Line Of Credit | Prime Rate | Minimum
Debt
Effective interest rate		4.75%
2019 Credit Facility - Term Loan
Debt
End-of-term fee (as a percent)		7.00%
Agreement term		46 months
Effective interest rate					7.85%
Prepayment fee (as a percentage)		2.00%
Debt amount		$ 6,000,000
Number of months of interest only payment		16 months	12 months
Number of months of equal principal payments plus accrued interest		30 months
Outstanding balance					$ 6,000,000
2019 Credit Facility - Term Loan | Minimum
Debt
Effective interest rate		3.75%	4.75%		3.75%
2019 Credit Facility - Term Loan | Prime Rate
Debt
Interest rate, negative basis spread percentage		0.75%

Debt - Carrying Value (Details)

Debt - Carrying Value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt
Net carrying value of debt, Current Portion	$ 4,242	$ 670
Net carrying value of debt, Long-term debt	3,748	7,149
2019 Credit Facility
Debt
Debt, Current Portion	4,400	800
Less: Debt issuance costs, Current Portion	(158)	(130)
Net carrying value of debt, Current Portion	4,242	670
Debt, including end of term fee, Long-term debt	4,020	7,620
Less: Unamortized debt discounts, Long-term debt	(272)	(471)
Net carrying value of debt, Long-term debt	3,748	7,149
Total principal amount	8,420	8,420
Less: Discount attributable to warrants, end of term fee and debt issuance costs, Total	(430)	(601)
Net carrying value of debt, Total	$ 7,990	$ 7,819

Debt - Summary of Principal Rep

Debt - Summary of Principal Repayments of 2019 Credit Facility (Details) - 2019 Credit Facility - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt
2021	$ 4,400
2022	2,400
2023	1,620
Total principal amount	$ 8,420	$ 8,420

Stockholders' Equity - (Details

Stockholders' Equity - (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Common stock reserved
Dividends on common stock		$ 0
Reserved shares of common stock for future issuance		2,918,202	2,809,928
Common stock warrants
Common stock reserved
Reserved shares of common stock for future issuance		49,336	27,836
Options issued and outstanding
Common stock reserved
Reserved shares of common stock for future issuance		2,272,905	1,931,903
Shares available for future option grants
Common stock reserved
Reserved shares of common stock for future issuance		179,219	638,227
RSUs subject to future vesting
Common stock reserved
Reserved shares of common stock for future issuance		416,742	211,962
At-the-Market Sales Agreement
Common stock reserved
Maximum amount of shares for offering	$ 25
Maximum commission percentage	3.00%
Net proceeds	$ 2.1
Number of shares sold	468,427

Stockholders' Equity - Warrants

Stockholders' Equity - Warrants (Details) - USD ($)	Aug. 05, 2019	Jul. 06, 2018	Jul. 15, 2020	Jun. 30, 2015	Dec. 31, 2010
2019 Credit Facility
Warrants
Number of shares the warrant can be converted to			21,500
Warrant exercise price			$ 0.01
Fair Value Of Warrants			$ 152,000
Amount bank could receive if takes the option to put the warrants upon expiration or a liquidity event	$ 50,000
Warrants to Purchase Series A Redeemable Convertible Preferred Stock | SVB Credit Facility
Warrants
Number of shares the warrant can be converted to					9,229
Warrant exercise price					$ 26
Warrants to Purchase Series B Redeemable Convertible Preferred Stock | 2015 Credit Facility
Warrants
Number of shares the warrant can be converted to				18,461
Warrant exercise price				$ 26
Warrants to Purchase Series B Redeemable Convertible Preferred Stock | SVB Credit Facility
Warrants
Number of shares the warrant can be converted to		9,375
Warrant exercise price		$ 8.91
Fair Value Of Warrants		$ 43,000
Warrant exercise expiration period		5 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Options and Awards Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Stock-based compensation
Options and Awards Available for Grant, Outstanding, Beginning balance	638,227
Options and Awards Available for Grant, Options authorized	542,452
Options and Awards Available for Grant, Options granted	(894,955)
Options and Awards Available for Grant, Options cancelled/forfeited	306,237
Options and Awards Available for Grant, Outstanding, Ending balance	179,219	638,227
Number of Options, Outstanding, Beginning balance	1,931,903
Number of Options, Options granted	894,955
Number of Options, Options exercised	(223,463)
Number of Options, Options cancelled/forfeited	(330,490)
Number of Options, Outstanding, Ending balance	2,272,905	1,931,903
Number of Options, exercisable	1,048,021
Weighted - Average Exercise Price Per Share, Options outstanding, Beginning balance	$ 7.17
Weighted - Average Exercise Price Per Share, Options granted	2.74
Weighted - Average Exercise Price Per Share, Options exercised	5.23
Weighted - Average Exercise Price Per Share, Options cancelled/forfeited	7.45
Weighted - Average Exercise Price Per Share, Options outstanding, Ending balance	5.58	$ 7.17
Weighted - Average Exercise Price Per Share, Options exercisable	$ 7.28
Weighted - Average Remaining Contractual Life, Options outstanding	7 years 10 months 24 days	6 years 6 months
Weighted - Average Remaining Contractual Life, Options exercisable	6 years 9 months 18 days
Aggregate Intrinsic Value, Options outstanding	$ 1,640	$ 188
Aggregate Intrinsic Value, Options exercised	355
Aggregate Intrinsic Value, Options exercisable	$ 13
Restricted stock units
Stock-based compensation
Options and Awards Available for Grant, RSUs granted	(469,304)
Options Available for Grant, RSUs cancelled/forfeited	56,562

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	Oct. 07, 2016	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation
Total grant date fair value of options vested		$ 2,200,000	$ 2,300,000
Weighted-average grant date fair value of options granted		$ 1.81	$ 4.06
Shares available for future issuance (in shares)		179,219	638,227
Value of share issued		$ 1,595,000	$ 282,000
Weighted-average exercise price (per share)		$ 5.58	$ 7.17
Number of stock options granted (in shares)		894,955
Options remained outstanding		2,272,905	1,931,903
2016 Employee Incentive Plan
Share-based Compensation
Maximum number of common stock shares may be issued under the plan	500,000
Annual increases in the number of shares available for issuance, percentage of outstanding capital stock	3.00%
2008 Equity Incentive Plan
Share-based Compensation
Vesting period		4 years
Exercise period		10 years
Number of stock options granted (in shares)		0
Options remained outstanding		157,329
2008 Equity Incentive Plan | Incentive Stock Options | Minimum
Share-based Compensation
Percentage of exercise price of fair market value of stock at the date of grant		100.00%
2008 Equity Incentive Plan | Incentive Stock Options | Maximum
Share-based Compensation
Percentage of exercise price of fair market value of stock at the date of grant		110.00%
2016 Employee Stock Purchase Plan
Share-based Compensation
Shares available for future issuance (in shares)		526,863
Value of share issued		$ 112,000	$ 232,000
Number of shares issued (in shares)		49,951	44,344

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Weighted Average Exercise Price Per Share
Unrecognized stock-based compensation expense | $	$ 3.2
Unrecognized compensation expense, weighted-average period expected to be recognized	2 years 8 months 12 days
Restricted stock units
Number of Restricted Stock Units
Balance, beginning of period | shares	211,962
Granted | shares	469,304
Vested | shares	(207,962)
Cancelled/forfeited | shares	(56,562)
Balance, end of period | shares	416,742
Weighted Average Exercise Price Per Share
Balance, beginning of period (price per share) | $ / shares	$ 6.97
Granted (price per share) | $ / shares	4.52
Vested (price per share) | $ / shares	6.10
Cancelled/forfeited (price per share) | $ / shares	5.18
Balance, end of period (price per share) | $ / shares	$ 4.89
2016 Employee Incentive Plan | Restricted stock units
Weighted Average Exercise Price Per Share
Unrecognized stock-based compensation expense | $	$ 1.4
Unrecognized compensation expense, weighted-average period expected to be recognized	2 years 1 month 6 days

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Fair Value of Employee Stock Options (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee | Options to purchase common stock
Share-based Compensation
Expected volatility, Minimum	74.40%	65.10%
Expected volatility, Maximum	79.30%	74.40%
Risk-free interest rate, Minimum	0.22%	1.46%
Risk-free interest rate, Maximum	1.63%	2.52%
Minimum | Employee | Options to purchase common stock
Share-based Compensation
Expected term (in years)	6 years 25 days	5 years 3 months 18 days
Maximum | Employee | Options to purchase common stock
Share-based Compensation
Expected term (in years)	6 years 29 days	6 years 1 month 6 days
2016 Employee Stock Purchase Plan
Share-based Compensation
Expected volatility, Minimum	44.70%	39.60%
Expected volatility, Maximum	100.70%	74.20%
Risk-free interest rate, Minimum	0.12%	1.67%
Risk-free interest rate, Maximum	1.68%	2.66%
2016 Employee Stock Purchase Plan | Minimum
Share-based Compensation
Expected term (in years)	6 months	6 months
2016 Employee Stock Purchase Plan | Maximum
Share-based Compensation
Expected term (in years)	1 year	1 year

Significant Agreements (Details

Significant Agreements (Details) - USD ($) $ in Thousands	Oct. 17, 2014	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Joint development agreement
Research and development expense			$ 10,896	$ 14,183
Revenue			$ 42,031	$ 37,503
Common Stock
Joint development agreement
Number of shares sold			468,427	888,987
Royalties
Joint development agreement
Revenue			$ 998	$ 1,070
Joint Development Agreement | Global Foundries, Inc.
Joint development agreement
Period of possession of exclusive right to manufacture after qualification of device	3 years
Period of possession of exclusive right to manufacture after completion of device development work	4 years
Research and development expense			0	1,800
Collaborative Agreement | Silterra
Joint development agreement
Non-recurring engineering cost obligation		$ 1,000
JCA costs was paid			$ 0	$ 200	$ 600

Restructuring (Details)

Restructuring (Details)	12 Months Ended
	Dec. 31, 2019USD ($)position
Restructuring
Number of positions | position	15
Restructuring expenses | $	$ 782,000

Geographic Information (Details

Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Geographic Information
Property and equipment, net	$ 1,946	$ 3,479
Revenue	42,031	37,503
Hong Kong
Geographic Information
Revenue	18,258	10,144
United States
Geographic Information
Property and equipment, net	1,415	2,235
Revenue	5,743	4,915
Japan
Geographic Information
Revenue	5,403	5,660
Canada
Geographic Information
Revenue	3,423	1,714
Germany
Geographic Information
Revenue	2,867	6,423
China
Geographic Information
Revenue	2,403	1,361
Singapore
Geographic Information
Property and equipment, net	287	789
All other
Geographic Information
Property and equipment, net	244	455
Revenue	$ 3,934	$ 7,286

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Current
Foreign	$ 260
Total Current	260
Provision for income taxes	$ 260

Income Taxes - Reconciliation E

Income Taxes - Reconciliation Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Provision for income taxes	$ 260
Reconciliation of statutory federal income tax
Tax at statutory federal rate	(21.00%)	(21.00%)
State taxes, net of federal benefit	(1.50%)	(0.80%)
Stock-based compensation	5.40%	2.00%
Change in uncertain tax benefits	3.10%
Change in valuation allowance	17.00%	18.90%
Other		0.90%
Provision for income taxes	3.00%	0.00%

Income Taxes - Deferred tax ass

Income Taxes - Deferred tax assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 31,683	$ 29,684
Inventory	147	874
Accruals	254	430
Depreciation and amortization	240	143
Limitation on business interest	268	186
Stock-based compensation	676	546
Right of use liability	549	776
Gross deferred tax assets	33,817	32,639
Valuation allowance	(33,265)	(31,840)
Deferred tax assets	552	799
Deferred tax liabilities:
Right of use asset	(527)	(710)
Other	(25)	(89)
Deferred tax liabilities	(552)	(799)
Increase in valuation allowance	$ 1,400	$ 2,800
Tax at statutory federal rate	21.00%	21.00%

Income Taxes - Net operating lo

Income Taxes - Net operating loss carryforwards and Tax Act (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net operating loss carryforwards
Net operating loss carryforwards, which will expire if not utilized	$ 99.7
Tax at statutory federal rate	21.00%	21.00%
Federal
Net operating loss carryforwards
Net operating loss carryforwards	$ 140.5
Net operating loss carryforwards, which will carryover indefinitely	40.8
State
Net operating loss carryforwards
Net operating loss carryforwards	54.1
Net operating loss carryforwards, which will expire if not utilized	51.5
Net operating loss carryforwards, which will carryover indefinitely	$ 2.6

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Unrecognized tax expense rollforward
Increase related to prior year tax positions	$ 91
Increase related to current year tax positions	13
Unrecognized tax expense, end of year	104
Interest and penalties on unrecognized tax benefit	$ 156	$ 0

Net Loss Per Common Share - Com

Net Loss Per Common Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ (8,512)	$ (14,669)
Denominator:
Weighted-average common shares outstanding used to calculate net loss per common share, basic and diluted	18,782,287	17,317,042
Net loss per common share, basic and diluted	$ (0.45)	$ (0.85)

Net Loss Per Common Share - Sch

Net Loss Per Common Share - Schedule of Potentially Dilutive Securities Excluded from Diluted Net Loss Per Common Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	2,738,983	2,171,701
Options to purchase common stock
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	2,272,905	1,931,903
Restricted stock units
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	416,742	211,962
Common stock warrants
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	49,336	27,836