Balance Sheet Components (Details) - USD ($) $ in Thousands	Jun. 28, 2015	Dec. 28, 2014
Inventories:
Raw material	$ 0	$ 0
Work-in-process	1,798	1,191
Finished goods	1,203	3,761
Inventories	3,001	4,952
Other current assets:
Prepaid expenses	765	1,042
Other	108	104
Other current assets	873	1,146
Accrued liabilities:
Employee related accruals	1,792	1,356
Restructuring accruals - See Note 12	169	0
Other	108	218
Accrued liabilities	$ 2,069	$ 1,574