Note 3 - STRATEGIC PARTNERSHIP AGREEMENT WITH ADVANTEST AND RELATED PARTY TRANSACTIONS (Details) - USD ($)		3 Months Ended								12 Months Ended
	Jul. 29, 2020	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Proceeds from Issuance of Common Stock											$ 65,078,000
Revenue from Contract with Customer, Including Assessed Tax		$ 29,886,000	$ 29,555,000	$ 27,419,000	$ 24,200,000	$ 22,367,000	$ 23,112,000	$ 21,409,000	$ 21,158,000	$ 111,060,000	88,046,000
Strategic Partnership for Joint Development and Sales Technology Solutions [Member]
Stock Issued During Period, Shares, New Issues (in shares)	3,306,924
Proceeds from Issuance of Common Stock	$ 65,200,000
Amendment #1 to Software License & Related Services Agreement [Member]
Revenue from Contract with Customer, Including Assessed Tax										10,600,000	3,400,000
Related Party Transaction, Due from (to) Related Party, Total		0				300,000				0	300,000
Contract with Customer, Liability, Total		$ 6,800,000				$ 5,900,000				6,800,000	5,900,000
Commercial Agreement With Advantest [Member]
Costs and Expenses, Related Party										$ 0	$ 0