IRQ
|
Bus Line?
|
Priority
|
Typical Default Use
|
Other Common Uses
|
0
|
no
|
1
|
System timer
|
None
|
1
|
no
|
2
|
Keyboard controller
|
None
|
2
|
no (rerouted)
|
n/a
|
None; cascade for
IRQs 8-15. Replaced by IRQ 9
|
Modems, very old (EGA) video cards,
COM3 (third serial port), COM4 (fourth serial port)
|
3
|
8/16-bit
|
11
|
COM2 (second serial port)
|
COM4 (fourth serial port), modems,
sound cards, network cards, tape accelerator cards
|
4
|
8/16-bit
|
12
|
COM1 (first serial port)
|
COM3 (third serial port), modems,
sound cards, network cards, tape accelerator cards
|
5
|
8/16-bit
|
13
|
Sound card
|
LPT2 (second parallel port), LPT3
(third parallel port), COM3 (third serial port), COM4 (fourth serial port),
modems, network cards, tape accelerator cards, hard disk controller on old
PC/XT
|
6
|
8/16-bit
|
14
|
Floppy disk controller
|
Tape accelerator cards
|
7
|
8/16-bit
|
15
|
LPT1 (first parallel port)
|
LPT2 (second parallel port), COM3
(third serial port), COM4 (fourth serial port), modems, sound cards, network
cards, tape accelerator cards
|
8
|
no
|
3
|
Real-time clock
|
None
|
9
|
16-bit only
|
4
|
Network cards, sound cards, SCSI host
adapters, PCI devices, rerouted IRQ2 devices
|
|
10
|
16-bit only
|
5
|
Network cards, sound cards, SCSI host
adapters, secondary IDE channel, quaternary IDE channel, PCI devices
|
|
11
|
16-bit only
|
6
|
Network cards, sound cards, SCSI host
adapters, VGA video cards, tertiary IDE channel, quaternary IDE channel, PCI
devices
|
|
12
|
16-bit only
|
7
|
PS/2 mouse
|
Network cards, sound cards, SCSI host
adapters, VGA video cards, tertiary IDE channel, PCI devices
|
13
|
no
|
8
|
Floating Point
Unit (FPU / NPU / Math Coprocessor)
|
None
|
14
|
16-bit only
|
9
|
Primary IDE channel
|
SCSI host adapters
|
15
|
16-bit only
|
10
|
Secondary IDE channel
|
Network cards, SCSI host adapters
|
IRQ: Interrupt Request (Pedido de
Interrupción)
En los PCs, un IRQ es una señal de un
dispositivo de hardware (por ej. el teclado o tarjeta de sonido) indicando que
el dispositivo necesita que la CPU haga algo. La señal del pedido de
interrupción va a través de las líneas IRQ a un controlador que asigna
prioridades a los pedidos IRQ y se los entrega a la CPU. Ya que el controlador
de IRQ espera señales de solo un dispositivo por línea IRQ, si tienen más que
un dispositivo por línea terminan con un conflicto de IRQ que puede congelar su
máquina. Esto es por qué asignar IRQs a dispositivos nuevos al instalarlos es
tan importante - y por qué puede ser tan frustrante cuando no se hace bien.
Son 16 IRQ’S que van del 0 al 15
