Balance Sheet Components (Details) - USD ($) $ in Thousands	Dec. 29, 2019	Dec. 30, 2018
Inventories:
Raw material	$ 222	$ 191
Work-in-process	2,370	2,929
Finished goods	668	716
Inventories	3,260	3,836
Other current assets:
Prepaid expenses	1,296	1,483
Other	269	292
Other current assets	1,565	1,775
Property and equipment:
Property and equipment, gross	12,993	14,149
Accumulated depreciation and amortization	(12,163)	(12,700)
Property and equipment, net	830	1,449
Capitalized internal-use software:
Capitalized during the year	365
Accumulated amortization	(32)
Internal use software net	333
Accrued liabilities:
Employee compensation related accruals	713	1,154
Other	420	749
Accrued liabilities	1,133	1,903
Equipment
Property and equipment:
Property and equipment, gross	10,694	10,607
Software
Property and equipment:
Property and equipment, gross	1,789	2,788
Furniture and fixtures
Property and equipment:
Property and equipment, gross	36	42
Leasehold improvements
Property and equipment:
Property and equipment, gross	$ 474	$ 712