Ampro Corporation MightyBoard 821 Interrupt Channel Assignments, Memory Map, Device vs IRQ No

Chapter 3 Hardware

Interrupt Channel Assignments

The interrupt channel 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

D

Keyboard

D

Secondary Cascade

D

COM1

O

D

COM2

D

O

COM3

O

D

COM4

D

O

Parallel

O

D

RTC

D

IDE

D

O

Math Coprocessor

D

PS/2 Mouse

D

PCI INTA

Automatically Assigned

PCI INTB

Automatically Assigned

PCI INTC

Automatically Assigned

PCI INTD

Automatically Assigned

PCI INTE

Automatically Assigned

PCI INTF

Automatically Assigned

PCI INTH

Automatically Assigned

Sound Blaster

D

O

O

O

USB

Automatically Assigned

VGA

Automatically Assigned

Ethernet

Automatically Assigned

Legend: D = Default, O = Optional

NOTE The IRQs for the Ethernet, Video, and Internal LPC bus 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. These are DOS-level addresses. The OS typically hides these physical addresses by way of memory management. Memory below 000500h is used by the BIOS.

16 Reference Manual MightyBoard 821