Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)

LOOK UP ANOTHER TERM


XN bit

(eXecute Never bit) See never execute bit.



never execute bit

A method for specifying areas of memory that cannot be used for execution. Supported by the CPU's virtual memory function, the bit is a flag (an indicator) in a virtual memory page. It can be used to isolate memory for storage versus instructions, as well as a security measure to ensure that malware instructions are not executed in memory areas where only data are expected to reside.

NX, XD and XN
Depending on the architecture, the never execute bit is called "NX" (never execute), "XD" (execute disable) or "XN" (execute never). See virtual memory. See also no-op.



Personal Use Only

Before/After Your Search Term
BeforeAfter
XML tagXNA
XML tag setXnix
XML vocabularyXNOR
XML websiteXNS
XMLPXO computer
XmodemXO laptop
XMPXO tablet
XMPPXohm
XMSXoIP
XMTxon-xoff

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
Audio/VideoGraphics
MainframesSecurity
ProgrammingHealthcare IT
System design