Technical Reference Guide

4.2.7 PCI CONFIGURATION

PCI bus operations require the configuration of certain parameters such as PCI IRQ routing, DMA channel configuration, RTC control, port decode ranges, and power management options. These parameters are handled by the LPC I/F bridge function (PCI function #0, device 31) of the ICH2 component and configured through the PCI configuration space registers listed in Table 4-4. Configuration is provided by BIOS at power-up but re-configurable by software.

Table 4-4.LPC Bridge Configuration Registers (ICH2, Function 0)

Table 4-4.

LPC Bridge Configuration Registers

(ICH2, Function 0, Device 31)

 

PCI

 

 

PCI

 

 

 

 

Config.

Register

Reset

Config.

 

Reset

 

Addr.

Value

Addr.

Register

Value

 

00, 01h

Vendor ID

8086h

8Ah

Device 31 Error Status

00h

 

 

02, 03h

Device ID

2440h

90, 91h

PCI DMA Configuration

0000h

 

 

04, 05h

Command

000Fh

A0-CFh

Power Management

 

 

 

06, 07h

Status

0280h

D0-D3h

General Control

0’s

 

 

08h

Revision ID

00h

D4-D7h

General Status

F00h

 

 

0A-0Bh

Class Code

0106h

D8h

RTC Configuration

00h

 

 

0Eh

Header Type

80h

E0h

LPC COM Port Dec. Range

00h

 

 

40-43h

ACPI Base Address

1

E1h

LPC FDD & LPT Dec. Rge

00h

 

 

44h

ACPI Control

00h

E2h

LPC Audio Dec. Range

80h

 

 

4E, 4Fh

BIOS Control

0000h

E3h

FWH Decode Enable

FFh

 

 

54h

TCO Control

00h

E4, E5h

LPC I/F Decode Range 1

0000h

 

 

58-5Bh

GPIO Base Address

1

E6, E7h

LPC I/F Enables

0000h

 

 

5Ch

GPIO Control

00h

E8-EBh

FWH Select 1

00112233

 

 

60-63h

INTA-D Routing Cntrl.

80h [1]

EC, EDh

LPC I/F Decode Range 2

0000h

 

 

64h

Serial IRQ Control

10h

EE, EFh

FWH Select 2

5678h

 

 

68-6B

INTE-F Routing Cntrl.

80h [1]

F0h

FWH Decode Enable 2

0Fh

 

 

88h

Dev. 31 Error Config.

00h

F2h

Function Disable Register

00h

 

NOTE:

[1] Value for each byte.

Assume unmarked locations/gaps as reserved.

Compaq Evo and Workstation Personal Computers 4-9

Featuring the Intel Pentium 4 Processor

Second Edition - January 2003

Page 63
Image 63
Compaq W4000 manual PCI Configuration, LPC Bridge Configuration Registers ICH2, Function 0, Device, Config Register Reset