Equity Plans

As of September 3, 2015, our equity plans permit us to issue an aggregate of up to 170 million shares of common stock, of which 112 million shares were available for future awards. Awards are subject to terms and conditions as determined by our Board of Directors.

Stock Options

Our stock options are generally exercisable in increments of either one-fourth or one-third per year beginning one year from the date of grant. Stock options issued after February 2014 generally expire eight years from the date of grant. Options issued prior to February 2014 generally expire six years from the date of grant.

Option activity for 2015 is summarized as follows:



	Number of Shares		Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Life (In Years)	Aggregate Intrinsic Value
Outstanding at August 28, 2014	48		$	10.57
Granted	8		34.45
Exercised	(10	)	7.35
Canceled or expired	(2	)	15.93
Outstanding at September 3, 2015	44		15.33		3.8	$	256

Exercisable at September 3, 2015	18		$	9.33	2.4	$	145
Expected to vest after September 3, 2015	25		19.11		4.7	109

The total intrinsic value was $229 million, $421 million, and $103 million for options exercised during 2015, 2014, and 2013, respectively.

Stock options granted and assumptions used in the Black-Scholes option valuation model were as follows:



For the year ended	2015			2014			2013
Stock options granted	8			12			18
Weighted-average grant-date fair value per share	$	14.79		$	9.64		$	3.34
Average expected life in years	5.6			4.9			5.1
Weighted-average expected volatility	45		%	48		%	59		%
Weighted-average risk-free interest rate	1.7		%	1.6		%	0.7		%

The expected volatilities utilized were based on implied volatilities from traded options on our stock and on our historical volatility. The expected lives of options granted were based, in part, on historical experience and on the terms and conditions of the options. The risk-free interest rates utilized were based on the U.S. Treasury yield in effect at each grant date. No dividends were assumed in estimated option values.

Restricted Stock and Restricted Stock Units ("Restricted Stock Awards")

As of September 3, 2015, there were 14 million shares of Restricted Stock Awards outstanding, of which 1 million were performance-based or market-based Restricted Stock Awards. For service-based Restricted Stock Awards, restrictions generally lapse in one-fourth increments during each year of employment after the grant date. Vesting for performance-based awards is contingent upon meeting a specified return on assets ("ROA"), as defined, over a three-year performance period and vesting for market-based Restricted Stock Awards is contingent upon achieving total shareholder return ("TSR") relative to the companies included in the S&P 500 over a three-year performance period. At the end of the performance period, the number of actual shares to be awarded varies between 0% and 200% of target amounts, depending upon the achievement level of the specified ROA or TSR. Restricted Stock Awards activity for 2015 is summarized as follows:



	Number of Shares		Weighted-Average Grant Date Fair Value Per Share
Outstanding at August 28, 2014	13		$	15.08
Granted	7		32.60
Restrictions lapsed	(5	)	13.48
Canceled	(1	)	19.81
Outstanding at September 3, 2015	14		23.88

Expected to vest after September 3, 2015	13		$	23.78



For the year ended	2015		2014		2013
Restricted stock awards granted	7		7		7
Weighted-average grant-date fair values per share	$	32.60	$	21.88	$	6.23
Aggregate fair values at vesting date	155		115		17

Stock-based Compensation Expense



For the year ended	2015		2014		2013
Stock-based compensation expense by caption:
Cost of goods sold	$	65	$	39	$	27
Selling, general and administrative	60		50		45
Research and development	42		25		18
Other	1		1		1
	$	168	$	115	$	91

Stock-based compensation expense by type of award:
Stock options	$	81	$	61	$	57
Restricted stock awards	87		54		34
	$	168	$	115	$	91

Stock-based compensation expense of $9 million and $9 million was capitalized and remained in inventory as of September 3, 2015 and August 28, 2014, respectively. As of September 3, 2015, $384 million of total unrecognized compensation costs for unvested awards, net of estimated forfeitures, was expected to be recognized through the fourth quarter of 2019, resulting in a weighted-average period of 1.3 years. Stock-based compensation expense in the above presentation does not reflect any significant income tax benefits, which is consistent with our treatment of income or loss from our U.S. operations.