APIC

Short for Advanced Programmable Interrupt Controller, APIC is a PIC (Programmable Interrupt Controller) with advanced interrupt management. It was developed by Intel and replaces the 8259 interrupt controllers. APIC is necessary for dual processing or multiple-processor support and has been available since the original Intel Pentium. However, the motherboard chipset, BIOS (Basic Input/Output System), and operating system (Windows 2000 and later) must also support APIC before it can be used.

Although APIC adds support for multiple processors, it is still used with single-processor computers since it provides support for virtual PCI (Peripheral Component Interconnect) IRQs above 15. Windows XP is one of the first versions of Windows that takes full advantage of APIC if enabled and assigns more devices to IRQs above 15.

AMD attempted to develop a competing technology, named OpenPIC, but it was never used with any x86 motherboards. AMD ended up licensing APIC for use with their Athlon and later processors.

Computer acronyms, Dual processor, Hardware terms, Interrupts, IRQL, PIC