WXB Hot-Plug

Bits Description

7:0 Revision Identification Number

This is an 8-bit value that indicates the revision identification number for the IHPC

WXB A Steppings:

Hardwired Value = 00h

WXB B0 Step:

Hardwired Value = 01h

8.1.7CLASS: Class Register

Address Offset:

09 – 0Bh

Size:

24 bits

Default Value:

080400h

Attribute:

Read-Only

This register contains the Class Code for the IHPC, specifying the device function. Writes to this register will have no effect.

Bits Description

23:16 Base Class

This field indicates the general device category. The IHPC is a Base System Peripheral. Hardwired Value = 08h.

15:8 Sub-Class

This field qualifies the Base Class, providing a more detailed specification of the device function. For the IHPC this field indicates a Generic PCI Hot-Plug Controller. Hardwired Value = 04h.

7:0 Register-level Programming Interface

This field identifies a specific programming interface (if any), that device independent software can use to interact with the device. The Interface is not defined. Hardwired Value = 00h.

8.1.8CLS: Cache Line Size

Address Offset:

0Ch

Size:

8 bits

Default Value:

00h

Attribute:

Read/Write

See PCI Specification, Rev. 2.2.

8.1.9MLT: Master Latency Timer Register

Address Offset:

0Dh

Size:

8 bits

Default Value:

00h

Attribute:

Read/Write

See PCI Specification, Rev. 2.2. This register is not applicable to the IHPC’s within the WXB.

8.1.10HDR: Header Register

Address Offset:

0Eh

Size:

8 bits

Default Value:

00h

Attribute:

Read-Only

This register identifies the header layout of the configuration space. Writes to this register will have no effect.

8-6

Intel® 460GX Chipset Software Developer’s Manual