Share-based compensation and the related tax benefit recognized in our condensed consolidated statements of operations were as follows (in millions):

	Three Months Ended				Nine Months Ended
	March 31,				March 31,
	2019		2018		2019		2018
Cost of revenue	$	0.7	$	0.9	$	2.4	$	2.3
Research and development		8.6		10.0		25.4		28.9
Selling, general, and administrative		6.5		7.9		20.9		21.9
Total	$	15.8	$	18.8	$	48.7	$	53.1
Income tax benefit on share-based compensation	$	1.8	$	3.7	$	4.2	$	6.4

Historically, we have issued new shares in connection with our share-based compensation plans, however, treasury shares are also available for issuance. Any additional shares repurchased under our common stock repurchase program will be available for issuance under our share-based compensation plans.

Stock option activity, including stock options granted, exercised, and forfeited, weighted average exercise prices for stock options outstanding and exercisable, and the aggregate intrinsic value were as follows:

	Stock			Weighted		Aggregate
	Option			Average		Intrinsic
	Awards			Exercise		Value
	Outstanding			Price		(in millions)
Balance as of June 30, 2018		1,618,209		$	57.14
Granted		-		-
Exercised		(167,663	)		29.34
Forfeited		(137,323	)		66.93
Balance as of March 31, 2019		1,313,223			59.67	$	2.2
Exercisable at March 31, 2019		1,231,738			60.09	$	2.2

The aggregate intrinsic value was determined using the closing price of our common stock on March 29, 2019 of $39.75 and excludes the impact of stock options that were not in-the-money.

DSU activity, including DSUs granted, delivered, and forfeited, and the balance and aggregate intrinsic value of DSUs were as follows:

				Aggregate
	DSU			Intrinsic
	Awards			Value
	Outstanding			(in millions)
Balance as of June 30, 2018		1,853,558
Granted		1,227,652
Delivered		(670,770	)
Forfeited		(288,773	)
Balance as of March 31, 2019		2,121,667		$	84.3

The aggregate intrinsic value was determined using the closing price of our common stock on March 29, 2019 of $39.75.

Of the shares delivered, 158,868 shares valued at $6.2 million were withheld to meet statutory tax withholding requirements.

Our Amended and Restated 2010 Incentive Compensation Plan provides for the grant of MSU awards to our employees, consultants, and directors. An MSU is a promise to deliver shares of our common stock at a future date based on the achievement of market-based performance requirements in accordance with the terms of the MSU grant agreement.

We have granted MSUs to our executive officers and other management members, which are designed to vest in three tranches with the target quantity for each tranche equal to one-third of the total MSU grant. The first tranche vests based on a one-year performance period; the second tranche vests based on a two-year performance period; and the third tranche vests based on a three-year performance period. Performance is measured based on the achievement of a specified level of total stockholder return, or TSR, relative to the TSR of the S&P Semiconductor Select Industry Index, or SPSISC Index, for grants made beginning in fiscal 2018, and relative to the Philadelphia Semiconductor Index, or SOX Index, for grants made prior to fiscal 2018. The potential payout ranges from 0% to 200% of the grant target quantity and is adjusted on a two-to-one ratio based on our TSR performance relative to the SPSISC Index TSR or SOX Index TSR using the following formula:

The payout for the first tranche and the second tranche will not exceed 100% and the payout for the third tranche will be calculated based on the total target quantity for the entire grant multiplied by the payout factor, based on performance for the three-year performance period, less shares issued for the first tranche and the second tranche.

Delivery of shares earned, if any, will take place on the dates provided in the applicable MSU grant agreement, assuming the grantee is still an employee, consultant, or director of our company at the end of the applicable performance period. On the delivery date, we withhold shares to cover statutory tax withholding requirements and deliver a net quantity of shares to the employee, consultant, or director after such withholding. Until delivery of shares, the grantee has no rights as a stockholder with respect to any shares underlying the MSU award.

During the nine months ended March 31, 2019, MSU activity, including MSUs granted, delivered, and forfeited, and the balance and aggregate intrinsic value of MSUs as of March 31, 2019 was as follows:

				Aggregate
	MSU			Intrinsic
	Awards			Value
	Outstanding			(in millions)
Balance as of June 30, 2018		354,726
Granted		163,059
Performance adjustment		(46,663	)
Delivered		(92,202	)
Forfeited		(53,115	)
Balance as of March 31, 2019		325,805		$	13.0

The aggregate intrinsic value was determined using the closing price of our common stock on March 29, 2019 of $39.75. Of the shares delivered, 33,981 shares valued at $1.3 million were withheld to meet statutory tax withholding requirements.

We value MSUs using the Monte Carlo simulation model on the date of grant and amortize the compensation expense over the three-year performance and service period on a straight-line basis. The unrecognized share-based compensation cost of our outstanding MSUs was approximately $13.0 million as of March 31, 2019, which will be recognized over a weighted average period of approximately 1.2 years.

Our Amended and Restated 2010 Incentive Compensation Plan provides for the grant of PSU awards to our employees, consultants, and directors. A PSU is a promise to deliver shares of our common stock at a future date based on the achievement of performance-based requirements in accordance with the terms of the PSU grant agreement.

We have granted PSUs to our executive officers and other management members, which are designed to vest in three tranches with the target quantity for each tranche equal to one-third of the total PSU grant. The grants have a specific one-year performance period and vesting occurs over three service periods with the final service period ending approximately three years from the grant date. Performance is measured based on the achievement of a specified level of non-GAAP earnings per share. The potential payout ranges from 0% to 200% of the grant target quantity and is adjusted on a linear basis with a payout triggering if our non-GAAP earnings per share equals greater than 65% of the target with a maximum payout achieved at 135% of target.

Delivery of shares earned, if any, will take place on the dates provided in the applicable PSU grant agreement, assuming the grantee is still an employee, consultant, or director of our company at the end of the applicable service period. On the delivery date, we withhold shares to cover statutory tax withholding requirements and deliver a net quantity of shares to the employee, consultant, or director after such withholding. Until delivery of shares, the grantee has no rights as a stockholder with respect to any shares underlying the PSU award.

During the nine months ended March 31, 2019, PSU activity, including PSUs granted, delivered, and forfeited, and the balance and aggregate intrinsic value of PSUs as of March 31, 2019 was as follows:

				Aggregate
	PSU			Intrinsic
	Awards			Value
	Outstanding			(in millions)
Balance as of June 30, 2018		294,541
Granted		147,005
Performance adjustment		1,065
Delivered		(92,470	)
Forfeited		(54,383	)
Balance as of March 31, 2019		295,758		$	11.8

The aggregate intrinsic value was determined using the closing price of our common stock on March 29, 2019 of $39.75. Of the shares delivered, 36,332 shares valued at $1.4 million were withheld to meet statutory tax withholding requirements.

We value PSUs using the aggregate intrinsic value on the date of grant adjusted for estimated performance achievement during the performance period and amortize the compensation expense over the three-year service period on a ratable basis. The unrecognized share-based compensation cost of our outstanding PSUs was approximately $4.6 million as of March 31, 2019, which will be recognized over a weighted average period of approximately 1.3 years.

Shares purchased, weighted average purchase price, cash received, and the aggregate intrinsic value for employee stock purchase plan purchases during the nine-month period ended March 31, 2019 were as follows (in millions, except for shares purchased and weighted average purchase price):