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244

Revision 3.0

Core Logic Module (Continued)

5.4.2.1

SMI Status Support Registers

F1 Index 10h, Base Address Register 0 (F1BAR0), points

to the base address for SMI Status register locations. Table

5-33 gives the bit formats of I/O mapped SMI Status regis-

ters accessed through F1BAR0.

The registers at F1BAR0+I/O Offset 50h-FFh can also be

accessed F0 Index 50h-FFh. The preferred method is to

program these registers through the F0 register space.

Table 5-33. F1BAR0+I/O Offset: SMI Status Registers

Bit

Description

Offset 00h-01h

Top Level PME/SMI Status Mirror Register (RO)

Reset Value: 0000h

Note:

Reading this register does not clear the status bits. For more information, see F1BAR0+I/O Offset 02h.

Suspend Modulation Enable Mirror. This bit mirrors the Suspend Mode Configuration bit (F0 Index 96h[0]). It is used by

the SMI handler to determine if the SMI Speedup Disable Register (F1BAR0+I/O Offset 08h) must be cleared on exit.

SMI SourceisUSB. Indicates whether or not an SMI was caused by USB activity

0: No.

1: Yes.

To enable SMI generation, set F5BAR0+I/O Offset 00h[20:19] to 11.

SMI Source is Warm Reset Command. Indicates whether or not an SMI was caused by a Warm Reset command.

0: No.

1: Yes.

SMI SourceisNMI. Indicates whether or not an SMI was caused by NMI activity.

0: No.

1: Yes.

SMI SourceisSuperI/O. Indicates whether or not an SMI was caused by SuperI/O.

0: No.

1: Yes.

The next level (second level) of SMI status is reported in the SuperI/O module. For more information, see Table 4-29 "Banks

0 and 1 - Common Control and Status Registers" on page 127, Offset 00h.

SMI SourceisEXT_SMI[7:0]. Indicates whether or not an SMI was caused by a negative-edge event on EXT_SMI[7:0].

0: No.

1: Yes.

The next level (second level) of SMI status is at F1BAR0+I/O Offset 24h[23:8].

SMI Source is GP Timers/UDEF/PCI/ISA Function Trap. Indicates if an SMI was caused by:

— Expiration of GP Timer 1 or 2.

— Trapped access to UDEF1, 2, or 3.

— Trapped access to F1-F5 or ISA Legacy register space.

0: No.

1: Yes.

The next level (second level) of SMI status is at F1BAR0+I/O Offset 04h/06h.

SMI Source is Software Generated. Indicates whether or not an SMI was caused by software.

0: No.

1: Yes.

SMIonanA20M# Toggle. Indicates whether or not an SMI was caused by a write access to either Port 92h or the keyboard

command which initiates an A20M# SMI.

0: No.

1: Yes.

This method of controlling the internal A20M# in the GX1 module is used instead of a pin.

To enable SMI generation, set F0 Index 53h[0] to 1.

SMI Source is a VGA Timer Event. Indicates whether or not an SMI was caused by the expiration of the VGA Timer (F0

Index 8Eh).

0: No.

1: Yes.

To enable SMI generation, set F0 Index 83h[3] to 1.

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