Equity Plans

As of February 28, 2013, we had an aggregate of 148.6 million shares of common stock reserved for the issuance of stock options and restricted stock awards, of which 104.3 million shares were subject to outstanding awards and 44.3 million shares were available for future awards. Awards are subject to terms and conditions as determined by our Board of Directors.

Stock Options

We granted 13.4 million and 17.3 million stock options during the second quarter and first six months of 2013, respectively, with weighted-average grant-date fair values per share of $3.35 and $3.27, respectively. We granted 14.5 million and 20.4 million stock options during the second quarter and first six months of 2012, respectively, with weighted-average grant-date fair values per share of $3.25 and $3.16, respectively.

The fair values of option awards were estimated at each grant date using the Black-Scholes option valuation model. The Black-Scholes model requires the input of assumptions, including the expected stock price volatility and estimated option life. The expected volatilities utilized were based on implied volatilities from traded options on our stock and on 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. Assumptions used in the Black-Scholes model are presented below:



	Quarter Ended				Six Months Ended
	February 28, 2013		March 1, 2012		February 28, 2013		March 1, 2012
Average expected life in years	5.1		5.1		5.1		5.1
Weighted-average expected volatility	59	%	66	%	60	%	66	%
Weighted-average risk-free interest rate	0.7	%	0.9	%	0.7	%	1.0	%

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

As of February 28, 2013, there were 13.4 million shares of Restricted Stock Awards outstanding, of which 3.5 million were performance-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. For performance-based Restricted Stock Awards, vesting is contingent upon meeting certain performance goals. Restricted Stock Awards granted for the second quarters and first six months of 2013 and 2012 were as follows:



	Quarter Ended				Six Months Ended
	February 28, 2013		March 1, 2012		February 28, 2013		March 1, 2012
Service-based awards	3.2		2.0		5.4		3.8
Performance-based awards	—		—		1.2		1.9
Weighted-average grant-date fair values per share	$	6.69	$	5.84	$	6.20	$	5.40

Stock-based Compensation Expense

Total compensation costs for our equity plans were as follows:



	Quarter Ended				Six Months Ended
	February 28, 2013		March 1, 2012		February 28, 2013		March 1, 2012
Stock-based compensation expense by caption:
Cost of goods sold	$	7	$	7	$	13	$	12
Selling, general and administrative	9		18		18		29
Research and development	5		5		9		9
	$	21	$	30	$	40	$	50

Stock-based compensation expense by type of award:
Stock options	$	14	$	19	$	27	$	31
Restricted stock awards	7		11		13		19
	$	21	$	30	$	40	$	50

As of February 28, 2013, $187 million of total unrecognized compensation costs, net of estimated forfeitures, related to non-vested awards was expected to be recognized through the second quarter of 2017, 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. (See "Income Taxes" note.)