View Source: APIC - Waikato Linux Users Group

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An [Acronym] for __A__dvanced __P__rogrammable __I__nterrupt Controller.

The [APIC] is split into two parts, the Local [APIC] and the [I/O]-[APIC].

The Local [APIC] is found on uniprocessor and mulitprocessor systems and built into recent [x86] chips (Pentium Pro and up). The Local [APIC] can be used by the OperatingSystem to program interrupts to wake up threads, on [SMP] machines it can be used to send interrupts to another processor. The Local [APIC] also has a handy timer in it, you can set the timer to whatever you want and it'll start generating interrupts.

The IO-APIC is only really useful for [SMP] systems. It is used for sending various interrupts to various [CPU]s in the system. Without an [I/O]-[APIC], interrupts from hardware only get delivered to the boot [CPU]. Another advantage is that [PCI] interrupts can be sent around the system without overlapping [IRQ]s.

See also: [Intel]’s [APIC notes | http://www.intel.com/design/chipsets/datashts/290566.htm]

One page links to APIC:

TroubleshootingStartUp

Last edited on Saturday, June 3, 2006 1:54:41 am by AristotlePagaltzis

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