4 HP BIOS

BIOS Addresses

Interrupt Controllers

The Interrupt Requests (IRQ) are numbered sequentially, starting with the master controller, and followed by the slave.

IRQ

Interrupt Request Description

(Interrupt Vector)

 

 

 

INTR

 

 

 

IRQ1

NS317 Keyboard Controller

 

 

IRQ0

PIIX4 System Timer

 

 

IRQ3

 

 

 

IRQ4

NS317 COM1, COM3

 

 

IRQ5

AD1816, LPT2

 

 

IRQ6

NS317 Flexible Disk Controller

 

 

IRQ7

NS317 LPT1

 

 

IRQ8

NS317 RTC

 

 

IRQ9

 

 

 

IRQ10

 

 

 

IRQ11

 

 

 

IRQ12

NS317 Mouse

 

 

not connected

 

 

 

IRQ14

PIIX4 IDE

 

 

IRQ15

 

 

 

PCI Interrupt Request Lines

PCI devices generate interrupt requests using up to four PCI interrupt request lines (INTA#, INTB#, INTC#, and INTD#).

PCI interrupts can be shared; several devices can use the same interrupt. However, optional system performance is reached when minimizing the sharing of interrupts. Refer to pages 27 and 28 for the Desktop and Mini- tower Backplane PCI Mapping tables, and page 39 for a table of the PCI device interrupts.

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