Condensed Unaudited Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 28, 2014		Sep. 29, 2013		Sep. 28, 2014		Sep. 29, 2013
Income Statement [Abstract]
Revenue	$ 4,124	[1]	$ 9,066	[1]	$ 22,124	[1]	$ 17,209	[1]
Cost of revenue	2,361		6,037		13,287		11,210
Gross profit	1,763		3,029		8,837		5,999
Operating expenses:
Research and development	3,057		2,052		8,754		5,902
Selling, general and administrative	2,579		3,207		8,892		8,648
Restructuring costs	0		(32)		0		181
Total operating expenses	5,636		5,227		17,646		14,731
Loss from operations	(3,873)		(2,198)		(8,809)		(8,732)
Gain on sale of TowerJazz Semiconductor Ltd. Shares	0		0		0		181
Interest expense	(34)		(8)		(67)		(37)
Interest income and other expense, net	(17)		(74)		(79)		(130)
Loss before income taxes	(3,924)		(2,280)		(8,955)		(8,718)
Provision for (benefit from) income taxes	6		(18)		(18)		369
Net loss	$ (3,930)		$ (2,262)		$ (8,937)		$ (9,087)
Net loss per share:
Basic (in dollars per share)	$ (0.07)		$ (0.05)		$ (0.16)		$ (0.20)
Diluted (in dollars per share)	$ (0.07)		$ (0.05)		$ (0.16)		$ (0.20)
Weighted average shares:
Basic (in shares)	55,812		44,761		55,208		44,640
Diluted (in shares)	55,812		44,761		55,208		44,640

[1] For all periods presented: New products include all products manufactured on 180 nanometer or smaller semiconductor processes. Mature products include all products produced on semiconductor processes larger than 180 nanometers.