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Table, Interrupt controllers – HP A7818-IE002 User Manual

Page 75

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System BIOS

BIOS Addresses

Chapter 3

75

The following table shows how the system allocates DMA channels.

Interrupt Controllers

The system’s interrupt controller is equivalent in function to two 82C59 interrupt
controllers. The following table shows how the interrupts are connected to the APIC
controller. The IRQs are numbered sequentially, starting with the master controller and
followed by the slave (both of 82C59 type).

DMA controller

Channel

Function

DMA 0

Free

DMA 1

Free if not used for parallel port in Setup

DMA 2

Floppy disk drive controller

DMA 3

Free if not used for parallel port in Setup

DMA 4

Used to cascade DMA channels 0-3

DMA 5

Free

DMA 6

Free

DMA 7

Free

I/O APIC Input

IRQ

IRQ Description

INTIN0

ICH

INTIN1

IRQ1

Super I/O keyboard controller

INTIN2

IRQ0

ICH system timer

INTIN3

IRQ3

Super I/O - Used by serial port if enabled

INTIN4

IRQ4

Super I/O - Used by serial port if enabled

INTIN5

IRQ5

Free if not used for parallel port or audio

INTIN6

IRQ6

Super I/O - floppy disk controller

INTIN7

IRQ7

Super I/O - LPT1

INTIN8

IRQ8

ICH - RTC

INTIN9

IRQ9

Available for PCI devices

INTIN10

IRQ10

Available for PCI devices

INTIN11

IRQ11

Available for PCI devices

INTIN12

IRQ12

Super I/O - mouse

INTIN13

IRQ13

Coprocessor

INTIN14

IRQ14

ICH - Integrated IDE Controller (primary)

INTIN15

IRQ15

ICH - Integrated IDE Controller (secondary)

INTIN16

PCINTA

INTIN17

PCINTB