# Interrupt Request (IRQ) Lines

&Matthias.Hoelzer-Kluepfel;
&Helge.Deller;
&Duncan.Haldane;
&Mike.McBride;
2002-02-12
3.00.00
KDE KControl IRQ interrupts system information

## Interrupt Request (IRQ) Lines in Use

This page displays information about the Interrupt Request Lines in use, and the devices that use them.

An IRQ is a hardware line used in a PC by (ISA bus) devices like keyboards, modems, sound cards, &etc;, to send interrupt signals to the processor to tell it that the device is ready to send or accept data. Unfortunately, there are only sixteen IRQ's (0-15) available in the i386 (PC) architecture for sharing among the various ISA devices.

Many hardware problems are the result of IRQ conflicts, when two devices try to use the same IRQ, or software is misconfigured to use a different IRQ from the one a device is actually configured for.

The exact information displayed is system-dependent. On some systems, IRQ information cannot be displayed yet.

On &Linux;, this information is read from `/proc/interrupts`, which is only available if the `/proc` pseudo-filesystem is compiled into the kernel.

The first column, is the IRQ number. The second column, is the number of interrupts that have been received since the last reboot. The third column shows the type of interrupt. The fourth, identifies the device assigned to that interrupt.

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