IRQ (Interrupt Request)

An interrupt request (IRQ) is a hardware signal sent to the processor instructing it to suspend its current activity and handle some external event, such as a keyboard input or a mouse movement. In x86 based computer systems, IRQs are numbered from 0 to 15. Newer computers, including x86-64 systems, provide more than these 16 interrupts (usually 24). Some interrupts are reserved for specific purposes, such as the keyboard and the real-time clock; others have common uses but may be reassigned; and some are left available for extra devices that may be added to the system.

Here is a list of the IRQs and their common purposes in the x86 system:

irq list and purpose

In Linux, IRQ mappings are stored in the /proc/interrupts file:

linux /proc/interrupts file

In the picture above, you can see the names of the drivers that are using each IRQ. For example, the floppy driver is using IRQ 6.

Subscribe to our Newsletter

Like us on Facebook

Geek University 2019