Memory map – Ampro Corporation XTX 820 User Manual

Page 23

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Chapter 3

Hardware

XTX 820

Reference Manual

17

Table 3-1. Interrupt Channel Assignments (IRQs)

IRQ#

Available

Typical Interrupt Source

Connected to Pin

0

No

Counter 0

NA

1

No

Keyboard

NA

2

No

Cascade Interrupt from Slave PIC

NA

3

Note 1

Serial Port 2 (COM2) / Generic

IRQ3 via SERIRQ

4

Note 1

Serial Port 1 (COM1) / Generic

IRQ4 via SERIRQ

5

Note 2

Parallel Port 2 (LPT2) / Generic

IRQ5 via SERIRQ

6

Note 1

Floppy Drive Controller / Generic

IRQ6 via SERIRQ

7

Note 1

Parallel Port 1 (LPT1) / Generic

IRQ7 via SERIRQ

8

No

Real-time Clock

NA

9

Note 4

SCI / Generic

IRQ9 via SERIRQ

10

Note 2, 1

Serial Port 3 (COM3) / Generic

IRQ10 via SERIRQ

11

Note 2, 1

Serial Port 4 (COM4) / Generic

IRQ11 via SERIRQ

12

Note 1

PS/2 Mouse / Generic

IRQ12 via SERIRQ

13

No

Math processor

NA

14

Note 1, 3

IDE Controller 0 (IDE0) / Generic

IRQ14

15

Note 1, 3

IDE Controller 1 (IDE1) / Generic

IRQ15

Notes: In PIC mode, the PCI bus interrupt lines can be routed to any free IRQ.

1. Default, but can be changed to another interrupt. If disabled in BIOS Setup, the interrupt can

be used for another purpose.

2. Function described is available if the baseboard is equipped with the Super I/O controller

Winbond (W83627HG). This I/O controller is supported by the XTX 820 Embedded BIOS.

3. If the ATA/IDE configuration is set to enhanced mode in BIOS setup (serial ATA and

parallel ATA native mode operation), IRQ14 and 15 are free for PCI/LPC bus.

4. In ACPI mode, IRQ9 is used for the SCI (System Control Interrupt). The SCI can be shared

with a PCI interrupt line.

Memory Map

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

Table 3-2. Memory Map

Address Range
(decimal)

Address Range
(hex)

Size

Description

(TOM-192kB) to TOM

NA

192 kB

ACPI reclaim, MPS and NVS area **

(TOM-8MB-192kB) to
(TOM-192kB)

NA

1 or 8 MB

VGA frame buffer *

1024 k to (TOM- 8MB
-192kB)

100000 - N.A

NA

Extended memory

869 k - 1024 k

E0000 - FFFFF

128 kB

Runtime BIOS

800 k - 869 k

CC000 - DFFFF

96 kB

Upper memory

640 k - 800 k

A0000 - CBFFF

160 kB

Video memory and Video BIOS

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