LPC/FWH Interface Configuration

Bit

Description

 

 

15:12

Reserved.

 

 

11

PWR_FAIL: This bit will be set to 1 when a power failure occurs. This is defined as either PWROK

 

or RSMRST# going inactive unexpectedly. This bit is only set by hardware and can only be reset by

 

writing a one to this bit position. This bit is not affected by a hard reset caused by a CF9 write. Upon

 

power up, this bit is set to ‘1’.

 

 

10

RI_STS: This bit will be set by 1 to hardware when the RI# input signal goes active. This bit can be

 

reset only by writing a one to this bit position. This bit is not affected by a hard reset caused by a

 

CF9 write.

 

 

9

Reserved.

 

 

8

USB1_STS: This bit is set when the USB controller for ports 0 and 1 needs to cause a wake/break

 

event. Additionally if the USB1_EN bit is set, the setting of the USB1_STS bit will generate a wake/

 

break event. This bit is only set by hardware and can only be reset by writing a one to this bit

 

position. This bit is not affected by a hard reset caused by a CF9 write.

 

 

7

THRMOR_STS: This is the thermal interrupt over-ride status. This bit is 1 anytime a thermal over-

 

ride condition occurs and starts throttling the CPU’s clock at the THRM_DTY ratio. This bit is set by

 

hardware and can only be cleared by writing a one to this bit position.

 

 

6:2

Reserved.

 

 

1

NMI_STS: This indicates that an external device generated SERR# or IOCHK#. If the NMI_EN bit is

 

set in the General Purpose 0 Enable Register, then the setting of this bit will generate an SCI. This

 

bit is set by hardware and can only be cleared by writing a ‘1’ to this bit position.

 

 

0

THRM_STS: This is the thermal interrupt status bit. This bit gets set anytime the THRM# signal is

 

driven active as defined by the THRM_POL bit. Additionally if the THRM_EN bit is set then the

 

setting of the THRM_STS bit will additionally generate a power management event (SCI or SMI).

 

This bit is only set through hardware (the THRM# signal being driven active), and is cleared by

 

software writing a one to this bit position.

 

 

11.2.7.6General Purpose 0 Enable

 

Address Offset:

OE-0Fh

 

Attributes:

 

Read/Write

 

Default Value:

0000h

 

Size:

 

16 bits

 

 

 

 

 

Bit

 

Description

 

 

 

 

 

15:13

Reserved.

 

 

 

 

 

12

AFTERG3: If set to 0, the IFB will boot the system after the power is returned after a power

 

 

failure. If set to 1, the IFB will not boot the system after a power failure and will wait for a wake

 

 

event (such as the Power Button being pressed). This bit is automatically set to 1 if a Power

 

 

Button Override occurs. Upon power up, this bit is undefined.

 

 

 

 

 

11

Reserved.

 

 

 

 

 

10

RI_EN: When RI_EN and RI_STS are both set, a Wake event will occur. If RI_EN is not set,

 

 

then when RI_STS is set, no Wake event will occur. This bit must be maintained even in the G3

 

 

state. This bit is automatically set to 0 if a Power Button Override occurs. Upon power up, this

 

 

bit is undefined.

 

 

 

 

 

9

Reserved.

 

 

 

 

 

8

USB1_EN: This bit is used to enable the setting of the USB1_STS bit to generate a wake/break

 

 

event. The USB1_STS bit is set anytime the USB controller for ports 0 and 1 signals a wake/

 

 

break event. The value of this bit must be maintained, even through a G3 state. The IFB will not

 

 

resume, from USB, after power failure (RSMRST# low). This bit is automatically set to 0 if a

 

 

Power Button Override occurs. Upon power up, this bit is undefined.

 

 

 

 

 

7:2

Reserved.

 

 

 

 

 

11-34

 

 

Intel® 460GX Chipset Software Developer’s Manual