Long-term debt (Tables)

6 Months Ended

Jul. 26, 2015

Debt Instrument [Line Items]

Schedule of Long-term Debt Instruments [Table Text Block]

	July 26,			January 25,
	2015			2015
	(In millions)
Amount of the equity component	$	126		$	126
1.00% Convertible Senior Notes Due 2018	$	1,500		$	1,500
Unamortized debt discount (1)	(101		)	(116		)
Net carrying amount	$	1,399		$	1,384

(1) As of July 26, 2015, the unamortized debt discount will be amortized over a remaining period of 3.4 years.

The following table presents interest expense for the contractual interest and the accretion of debt discount and issuance costs:

	Three Months Ended				Six Months Ended
	July 26,		July 27,		July 26,		July 27,
	2015		2014		2015		2014
	(In millions)
Contractual coupon interest expense	$	4	$	4	$	8	$	8
Amortization of debt discount and issuance costs	7		7		14		14
Total interest expense related to Notes	$	11	$	11	$	22	$	22