Ampro Corporation Littleboard 550 manual Interrupt Channel Assignments, Memory Map

Chapter 3 Hardware

Interrupt Channel Assignments

The channel interrupt assignments are shown in Table 3-1.

Table 3-1. Interrupt Channel Assignments

Device vs IRQ No.

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Timer

X

Keyboard

X

Secondary

X

Cascade

COM1

O

D

COM2

D

O

COM3

O

O

O

D

COM4

O

O

D

O

Floppy

X

Parallel

O

D

RTC

X

IDE Primary

X

O

IDE Secondary

O

X

Math Coprocessor

X

PS/2 Mouse

X

PCI INTA

Automatically Assigned

PCI INTB

Automatically Assigned

PCI INTC

Automatically Assigned

PCI INTD

Automatically Assigned

Sound Blaster

D

O

O

O

USB

Automatically Assigned

VGA

Automatically Assigned

Ethernet

Automatically Assigned

Legend: D = Default, O = Optional, X = Fixed

NOTE

The IRQs for the Ethernet, Video, and Internal Local Bus (ISA) are

automatically assigned by the BIOS Plug and Play logic. Local IRQs

assigned during initialization can not be used by external devices.

Memory Map

The following table provides the common PC/AT memory allocations. Memory below 000500h is used by the BIOS.

LittleBoard 550 Reference Manual 23