STOCK-BASED COMPENSATION - Schedule of Allocation of Recognized Period Cost (Details) - USD ($)	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total costs and expenses	$ 1,901,000	$ 1,441,000	$ 1,584,000
Stock-based compensation, capitalized costs	0	0	0
Cost of revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total costs and expenses	129,000	121,000	132,000
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total costs and expenses	760,000	614,000	658,000
Selling, general and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total costs and expenses	$ 1,012,000	$ 706,000	$ 794,000