Stock Based Compensation (Tables)

9 Months Ended

Oct. 25, 2015

Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]

Stock-based compensation expense, net of amounts capitalized as inventory

	Three Months Ended				Nine Months Ended
	October 25, 2015		October 26, 2014		October 25, 2015		October 26, 2014
	(In millions)
Cost of revenue	$	4	$	4	$	10	$	8
Research and development	28		22		82		65
Sales, general and administrative	19		16		53		42
Total	$	51	$	42	$	145	$	115

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award

	Awards Outstanding		Weighted Average Exercise Price
Stock Options	(In millions)		(Per share)
Balances, January 25, 2015	21		$14.61
Granted	—		—
Exercised	(6	)	$14.48
Cancelled	—		—
Balances, October 25, 2015	15		$14.55

	Awards Outstanding		Weighted Average Grant-Date Fair Value
RSUs, PSUs and Market-based PSUs	(In millions)		(Per share)
Balances, January 25, 2015	23		$15.94
Granted (1) (2)	13		$21.61
Vested	(8	)	$15.53
Cancelled	(2	)	$16.40
Balances, October 25, 2015	26		$18.84

(1) Includes the total PSUs that become eligible to vest if the corporate financial performance maximum target level for fiscal year 2016 is achieved. Using an estimate for the level of achievement of the corporate performance target at the end of fiscal year 2016, we are estimating PSUs that become eligible to vest for fiscal year 2016 performance to be in the range of 0 to 2 million shares. We granted PSUs during the first quarter of fiscal year 2016 to our CEO and senior management as approved by our Compensation Committee.

(2) Includes the market-based PSUs that become eligible to vest if the maximum target for total shareholder return, or TSR, over the 3-year measurement period is achieved. Depending on the ranking of our TSR compared to the respective TSRs of the companies comprising the Standard & Poor’s 500 Index during a 3-year measurement period, the market-based PSUs that become eligible to vest could range from 0 to 0.4 million shares. We granted market-based PSUs during the first quarter of fiscal year 2016 to our CEO and senior management as approved by our Compensation Committee.

Summary of unearned stock-based compensation expense

	October 25,	January 25,
	2015	2015
	(In millions)
Aggregate unearned stock-based compensation expense	$420	$291
Estimated weighted average amortization period	(In years)
Stock options	1.3	1.8
RSUs, PSUs and market-based PSUs	3.0	2.8
ESPP	0.8	0.5