Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 26, 2020	Jun. 28, 2019	Jun. 26, 2020	Jun. 28, 2019
Income Statement [Abstract]
Document Period End Date			Jun. 26, 2020
Net revenue	$ 736.8	$ 767.0	$ 2,398.9	$ 2,549.4
Cost of goods sold	402.7	454.5	1,244.9	1,351.6
Gross profit	334.1	312.5	1,154.0	1,197.8
Operating expenses:
Research and development	117.0	100.6	337.9	317.3
Selling, general and administrative	55.0	46.8	169.1	142.5
Amortization of intangibles	2.8	5.5	9.0	18.6
Total operating expenses	186.6	152.9	529.8	479.7
Operating income	147.5	159.6	624.2	718.1
Other income (expense), net	(3.5)	2.3	1.4	8.9
Income before income taxes	144.0	161.9	625.6	727.0
Provision for income taxes	14.3	17.8	57.7	84.0
Net income	$ 129.7	$ 144.1	$ 567.9	$ 643.0
Earnings per share:
Basic (in dollars per share)	$ 0.78	$ 0.83	$ 3.36	$ 3.69
Diluted (in dollars per share)	$ 0.77	$ 0.83	$ 3.33	$ 3.67
Weighted average shares:
Basic (in shares)	167.0	172.6	169.1	174.3
Diluted (in shares)	168.3	173.4	170.3	175.2
Common Stock, Dividends, Per Share, Declared	$ 0.44	$ 0.38	$ 1.32	$ 1.14
Restructuring Costs and Asset Impairment Charges	$ 11.8	$ 0.0	$ 13.8	$ 1.3