Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jan. 26, 2013	Jan. 28, 2012
Cash flows from operating activities:
Net loss	$ (11,996)	$ (5,308)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	984	1,475
Share-based compensation	1,387	1,921
Adjustments to provision for excess and obsolete inventory	144	74
Changes in operating assets and liabilities:
Accounts receivable	(655)	(3,503)
Inventories	(901)	1,795
Prepaids and other assets	361	(234)
Deferred revenue	(1,590)	1,807
Accounts payable	8	(364)
Accrued expenses and other liabilities	(1,815)	93
Accrued restructuring costs	232	(294)
Net cash used in operating activities	(13,841)	(2,538)
Cash flows from investing activities:
Purchases of property and equipment	(1)	(1,250)
Purchases of investments		(159,510)
Proceeds from maturities and sales of investments	274,719	155,270
Net cash provided by (used in) investing activities	274,718	(5,490)
Cash flows from financing activities:
Payment of cash distributions to common stockholders	(361,025)
Proceeds from issuance of common stock	38	610
Net cash (used in) provided by financing activities	(360,987)	610
Net decrease in cash and cash equivalents	(100,110)	(7,418)
Cash and cash equivalents, beginning of period	136,654	60,765
Cash and cash equivalents, end of period	36,544	53,347
Cash paid for income taxes	$ 1,174	$ 81