LPC/FWH Interface Configuration

Bit

Description

8PERR# Response (Not Implemented). Read as 0.

7Fast Back to Back–RO.This bit indicates to the PCI Master that IFB as a target is capable of accepting fast back-to-back transactions. This bit is hardwired to 1.

6:0 Reserved.

11.1.5RID–Revision Identification Register (Function 0)

Address Offset:

08h

Default Value:

Stepping Dependent

Attribute:

Read Only

This 8 bit register contains device stepping information. Writes to this register have no effect.

Bit

Description

7:0 Revision ID Byte.

11.1.6CLASSC–Class Code Register (Function 0)

Address Offset:

09h-0Bh

Default Value:

060100h

Attribute:

Read Only

This register identifies the Base Class Code, Sub-class Code, and Device Programming interface for the IFB PCI Function 0.

Bit

Description

23:16 Base Class Code (BASEC). 06h=Bridge device.

15:8 Sub-Class Code (SCC). 01h=PCI-to-ISA Bridge. ISA is not supported, IFB forwards cycles to the LPC interface.

7:0 Programming Interface (PI). 00h=No register level programming interface defined.

11.1.7HEDT–Header Type Register (Function 0)

Address Offset:

0Eh

Default Value:

80h

Attribute:

Read Only

The HEDT Register identifies the IFB as a multi-Function device.

Bit

Description

7:0 Device Type (DEVICET). 80h=multi-Function device.

Intel® 460GX Chipset Software Developer’s Manual

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