©2008 Advanced Micro Devices, Inc. SMBus Module and ACPI Block (Device 20, Function 0)
AMD SB600 Register Reference Manual Proprietary Page 160
MwaitEnable - RW – 8 bits - [PM_Reg: 5Eh]
Field Name Bits Default Description
MwaitEnable register
This register is used only in the P4 system.
MwaitSmiSts - RW – 8 bits - [PM_Reg: 5Fh]
Field Name Bits Default Description
Mwait_any_smi_sts 0 0b This bit indicates that SMI# is generated when any CPU is in
mwait state
Mwait_2cpu_smi_sts 1 0b This bit indicates that for 2 CPU system (dual core, non HT)
SMI# is generated when both CPUs are in mwait state
Mwait_4cpu_smi_sts 2 0b This bit indicates that for 4 CPU system (dual core, HT) SMI#
is generated when all 4 CPUs are in mwait state
Reserved 7:3 00h
MwaitSmiSts register
This register is used only in the P4 system.
Options_0 - RW – 8 bits - [PM_Reg: 60h]
Field Name Bits Default Description
TAlertFanEn 0 0b Set this bit to put all fans to full speed if T ALERT# is asserted
ProcHotFanEn 1 0b Set this bit to put all fans to full speed if PROCHOT# is
asserted
Fan1En 2 0b Setting this bit will configure GPIO48 pin to be FAN1 output
Fan2En 3 0b Setting this bit will configure GPIO49 pin to be FAN2 output
Reserved 4 0b
SpkrEn 5 0b Setting this bit will configure GPIO2 to be speaker output
Fan0En 6 0b Setting this bit will configure GPIO3 to be FAN0 output
Reserved 7 0b
Options_0 register
Options_1 - RW – 8 bits - [PM_Reg: 61h]
Field Name Bits Default Description
Reserved 0 0b
IsAmd 1 0b Set to enable NB/SB handshake during IOAPIC interrupt for
AMD K6 or K7 class; Clear for other CPU.
PCI_Active_enable 2 0b BIOS should set this bit in order to monitor BM_STS pin from
NB (the pin is called BMREQ# on SB) and bus mastering
from the SB itself.
UseCpuRst 3 1b If this bit is not set, then system reset will cause INIT# instead
of CPURST#.
ProcHotStsEn 4 0b Set to enable PROCHOT# to generate TwarnStatus and
thermal throttle
Reserved 5 0b
UsbPmeEnable 6 0b USB PME enable
Reserved 7 0b
Options_1 register
Shadow_SCI- R – 8 bits - [PM_Reg: 62h]
Field Name Bits Default Description
Shadow_SCI 0 0b SCI output
Reserved 7:1 00h
Shadow_SCI register