Chapter 4 System Support
Compaq Deskpro EX Series of Personal Computers
First Edition - August 2000
4-8
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 ICH
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 (ICH, Function 0)
Table 4-4.
LPC Bridge Configuration Registers
(ICH, Function 0, Device 31)
PCI
Config.
Addr.
Register
Reset
Value
PCI
Config.
Addr.
Register
Reset
Value
00, 01h
Vendor ID
8086h
8Ah
Device 31 Error Status
00h
02, 03h
Device ID
2410h
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
E8h
FWH Select
00
60-63h
INTA-D Routing Cntrl.
80h [1]
EC, EDh
LPC I/F Decode Range 2
0000h
64h
Serial IRQ Control
10h
EE, EFh
Reserved
--
65-87h
Reserved
--
F0h
Reserved
--
88h
Dev. 31 Error Config.
00h
F2h
Function Disable Register
00h
NOTE:
[1] Value for each byte.
Assume unmarked locations/gaps as reserved.