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Compaq W4000 User Manual

Page 59

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Technical Reference Guide

device being serviced by that bridge or it

ined for a device being serviced by a

on cycle

nd

e loa

g

e PCI bus. The D

be asserted high for the IDSEL signal, which

be con

unctio

er

thin a PC

I bridge

r a

i

o

ation of device numb

omponents and slots residing on a PCI bus.

ration Access

Table 4-1.

guration Acc

ess

Two types of configuration cycles are used. A Type 0 (zero) cycle is targeted to a device on the
PCI bus on which the cycle is running. A Type 1 cycle is targeted to a device on a downstream
PCI bus as identified by bus number bits <23..16>. With three or more PCI buses, a PC
may convert a Type 1 to a Type 0 if it’s de

ay forward the Type 1 cycle unmodified

dest

ow

bri

c

CF8h res

iguration cycle on th

etermines which one of the AD31..11 line

a

ct

n

I

its <10..8>) i

elect a particular f

on wi

igure 4-2. Configuration Cycle

AD31..0

(w/Type 00

C

s
ber

2 2

IDSEL (only one signal li

F8h

R

NOTES:

e

1

e 1

ycle only. Reserved on Ty

cy

stined fo

if it is

m
d

nstream

dge. Figure 4-2 shows the onfigurat

format a

how th

din of

0

ults in a Type 0 conf

evice Number (bits <15..11>

d

s is to

acts as “chip sele ” functio for the PC device t

figured. The f

n numb (CF8h,

b

s used to s

uncti

I component.

3

Devic

Numb

1 1

e

Function

Register

er

Number

Index

1 1

8 7

2 1 0 [1]

Bu

Num

Reserved

Register 0C

esults in:

ne asser

tion

er

R

ted)

Func

Numb

egister

Index


onfig. Cycle)


[1] Bits <1,0> : 00 = Typ
Type 01 c

0 Cycle, 0 = Typ

pe 00

cycle

cle.


F

Table 4-1 shows the standard configur

ers and IDSEL connections for

c

Table 4-1. PCI Device Configu

PCI Component Confi


PCI Component

Notes

Function #

Device #

PCI

Bus #

IDSEL

Wired to:

82845 MCH:
Memory Controller
AGP Bridge

0
0

0 (00h)
1 (01h)

0
0

--

AGP slot

0

0 (00h)

1

--

82801BA ICH2:
PCI Bridge


0

LPC Bridge

0

EIDE Controller
USB I/F #1
SMBus Co

Controller

oller

face Controller


[1]

1
2

5

30 (1Eh)
31 (1Fh)
31 (1Fh)
31 (1Fh)
31 (1Fh)

31 (1Fh)

0
0
0
0
0
0
0
0
2

--

ntroller

3

USB I/F #2
AC97 Audio
AC97 Modem Contr
Network Inter


4

6
0

31 (1Fh)

31 (1Fh)

8 (08h)

PCI Connector 1 (slot 1)

[2]

0

4 (04h)

2

AD20

PCI Connector 2 (slot 2)

[2]

2

AD25

0

9 (09h)

PCI Connector 3 (slot 3)

[2, 3]

)

2

AD26

0

10 (0Ah

PCI Connector 4 (slot 4)

[2, 4]

2

AD27

0

11 (0Bh)

PCI Connector 5 (slot 5)

[2, 4]

)

2

AD29

0

13 (0Dh

OTES:

[1]

Not

implement

[2] PCI bus number giv

N

ed.

en is for standard configuration.

er models only.

rable minitower models only.

[3] Desktop and Configurable Minitow

[4] Configu

Compaq Evo and Workstation Personal Computers

Featuring the Intel Pentium 4 Processor

Second Edition - January 2003

4-5