Chapter 4 System Support

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>. Figure 4-2 shows the configuration cycle format and how the loading of 0CF8h results in a Type 0 configuration cycle on the PCI bus. The Device Number (bits <15..11> determines which one of the AD31..11 lines is to be asserted high for the IDSEL signal, which acts as a “chip select” function for the PCI device to be configured. The function number (CF8h, bits <10..8>) is used to select a particular function within a PCI component.

31

24 23

16 15

 

11 10

8

7

2

1

0 [1]

Register 0CF8h

 

Reserved

 

Bus

Device

 

Function

Register

 

 

 

 

 

Number

Number

 

Number

 

 

Index

 

 

 

Results in:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AD31..0

 

 

 

 

 

 

 

 

 

 

 

 

IDSEL (only one signal line asserted)

 

Function

Register

 

 

 

(w/Type 00

 

 

Number

 

 

Index

 

 

 

Config. Cycle)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NOTES:

[1]Bits <1,0> : 00 = Type 0 Cycle, 01 = Type 1 cycle Type 01 cycle only. Reserved on Type 00 cycle.

Figure 4-2.Configuration Cycle

Table 4-1 shows the standard configuration of device numbers and IDSEL connections for components and slots residing on a PCI bus.

Table 4-1.PCI Device Configuration Access

Table 4-1.

PCI Component Configuration Access

 

PCI

 

 

 

IDSEL

PCI Component: Function

Bus #

Device #

Function #

Device ID [4]

Wired to: [4]

IGP:

 

 

 

 

n/a

CPU Host Bridge

0

0

0

01A4h / 01E0h

 

Memory Configuration

0

0

1

01Ach / 01EBh

 

Memory Addr. Trans. Cntrl.

0

0

2

01ADh / 01EEh

 

Miscellaneous Control

0

0

3

01AAh / 01EDh

 

AGP Host

0

30

0

01B7h / 01E8h

 

Graphics processing unit [1]

1

0

0

01A0h / 01F0h

 

AGP slot

1

0

0

[3]

n/a

MCP:

 

 

 

 

n/a

Legacy LPC Bridge Control

0

1

0

01B2h / 0060h

 

SMBus Control

0

1

1

01B4h / 0064h

 

USB Controller A

0

2

0

01C2h / 0067h

 

USB Controller B

0

2

1

01C2h / 0067h

 

USB 2.0 Controller

0

2

2

na / 0068h

 

Network interface

0

4

0

[2] / 0066h

 

Audio processor

 

5

0

[2] / [2]

 

Audio Codec

0

6

1

01B1h / 006Ah

 

Modem Codec (not used)

0

6

0

01C1h / 0069h

 

PCI-PCI Bridge

0

8

0

01B8h / 006Ch

 

IDE Controller

0

9

 

01BCh / 006Dh

 

PCI Connector 1 (slot 1)

2

6 / 4

[3]

[3]

AD22 / AD20

PCI Connector 2 (slot 2)

2

7 / 9

[3]

[3]

AD23 / AD25

PCI Connector 3 (slot 3)

2

8 / 10

[3]

[3]

AD24 / AD26

NOTES:

All numbers are in decimal unless otherwise indicated.

Vender ID for all functions is 10DEh.

[1]Will not be “visible” to software if an AGP card is installed in the AGP slot.

[2]Not used in this systems.

[3]Determined by installed device.

[4]D315 / d325

4-4Compaq D315 and hp d325 Personal Computers Featuring the AMD Athlon XP Processor

Second Edition – April 2003