Annual report pursuant to Section 13 and 15(d)

Note 1 - Summary of Significant Accounting Policies (Details Textual)

v3.21.2
Note 1 - Summary of Significant Accounting Policies (Details Textual)
$ in Thousands
12 Months Ended
Dec. 12, 2019
Mar. 27, 2021
USD ($)
Mar. 28, 2020
USD ($)
Mar. 31, 2019
USD ($)
Number of Leases   1    
Operating Lease, Right-of-Use Asset   $ 865 $ 1,183  
Operating Lease, Liability, Total   1,153    
Research and Development Expense, Total   2,153 1,552  
Asset Impairment Charges, Total   $ 0 $ 0  
Customer Concentration Risk [Member] | Accounts Receivable [Member]        
Number of Major Customers   2 3  
Concentration Risk, Percentage   95.00% 96.00%  
Minimum [Member]        
Warranty Term (Year)   1 year    
Minimum [Member] | Machinery and Equipment [Member]        
Property, Plant and Equipment, Useful Life (Year)   3 years    
Maximum [Member]        
Warranty Term (Year)   3 years    
Maximum [Member] | Machinery and Equipment [Member]        
Property, Plant and Equipment, Useful Life (Year)   10 years    
Accounting Standards Update 2016-02 [Member]        
Operating Lease, Right-of-Use Asset       $ 1,400
Operating Lease, Liability, Total       $ 1,800
Reverse Stock Split [Member]        
Stockholders' Equity Note, Stock Split, Conversion Ratio 15