Compaq 850 manual PCI Configuration Space Type, Bist

Technical Reference Guide

The register index (CF8h, bits <7..2>) identifies the 32-bit location within the configuration space of the PCI device to be accessed. All PCI devices can contain up to 256 bytes of configuration data (Figure 4-3), of which the first 64 bytes comprise the configuration space header.

Configuration

Space

Header

31	24	23		16	15	8	7	0
			Device-Specific Area
Min. Lat.			Min. GNT		Int. Pin		Int. Line
				Reserved
				Reserved
	Expansion ROM Base Address
	Subsystem ID				Subsystem Vendor ID
			Card Bus CIS Pointer
			Base Address Registers
	BIST		Hdr. Type		Lat. Timer		Line Size
			Class Code				Revision ID
	Status					Command
	Device ID					Vendor ID

Register

Index

FCh

40h

3Ch

38h

34h

30h

2Ch

28h

10h

0Ch

08h

04h

00h

31		24	23		16	15	8	7	0
				Device-Specific Area
	Bridge Control					Int. Pin		Int. Line
		Expansion ROM Base Address
					Reserved
I/O Limit Upper 16 Bits						I/O Base Upper 16 Bits
		Prefetchable Limit Upper 32 Bits
		Prefetchable Base Upper 32 Bits
Prefetch. Mem. Limit						Prefetch. Mem. Base
	Memory Limit						Memory Base
	Secondary Status					I/O Limit		I/O Base
	2nd			Sub. Bus #		Sec. Bus #		Pri. Bus #
				Base Address Registers
	BIST			Hdr. Type		Lat. Timer		Line Size
				Class Code				Revision ID
		Status					Command
	Device ID						Vendor ID

Register

Index

FCh

40h

3Ch

38h

34h

30h

2Ch

28h

24h

20h

1Ch

18h

10h

0Ch

08h

04h

00h

PCI Configuration Space Type 0 PCI Configuration Space Type 1

Data required by PCI protocol

Not required

Figure 4-3.PCI Configuration Space Mapping

Each PCI device is identified with a vendor ID (assigned to the vendor by the PCI Special Interest Group) and a device ID (assigned by the vendor). The device and vendor IDs for the devices on the system board are listed in Table 4-1.

Compaq Deskpro EXS and Workstation 300 Personal Computers 4-5

Featuring the Intel Pentium 4 Processor

First Edition - December 2000