AMD SB600 - Manual (Page 168)

©2008 Advanced Micro Devices, Inc. SMBus Module and ACPI Block (Device 20, Function 0)
AMD SB600 Register Reference Manual Proprietary Page 168
ThermThrotCntl – RW – 8 bits – [PM_Reg:86h]
Field Name Bits Default Description
ThrottleControl 4:1 0000b Bit[4] Enable thermal clock throttle
Bit[3:1] Throttle interval for STPCLK# de-assertion
000b: 50%
001b: 12.5%
010b: 25%
011b: 37.5%
100b: 50%
101b: 62.5%
110b: 75%
111b: 87.5%
ThermThrotPeriod 5 0b Selects the thermal clock throttle period
0: 30us
1: 244us
Reserved 6 0b
PllRstEn
(available after A13) 7 0b Resets PLL whenever the system gets reset.
ThermThrotCntl register
LdtStpCmd – RW – 8 bits – [PM_Reg:87h]
Field Name Bits Default Description
LSCmd 0 0b Write 1 to generate VID/FID change sequence with C3
STPCLK# message
Reserved 7:1 00h
LdtStpCmd register
LdtStartTime – RW – 8 bits – [PM_Reg:88h]
Field Name Bits Default Description
LdtStartTime 7:0 00h LDTSTP# assertion delay in 1us increment
LdtStartTime register for ACPI C state in the K8 system.
AgpStartTime – RW – 8 bits – [PM_Reg:89h]
Field Name Bits Default Description
AgpStartTime 7:0 00h AGP_STP# assertion delay in 1us increment
AgpStartTime register for ACPI C state in the K8 system.
LdtAgpTimeCntl – RW – 8 bits – [PM_Reg:8Ah]
Field Name Bits Default Description
LdtEndTime 1:0 00b LDTSTP# de-assertion delay select
00: 0 µs
01: 1 µs
10: 32 µs
11: 64 µs
Reserved 3:2 00b
VfidTime 6:4 000b VID/FID LDTSTP# duration select
000: 1 µs
001: 2 µs
010: 4 µs
011: 8 µs
100: 16 µs
101: 32 µs
110: 64 µs
111: 128 µs
StutterMode 7 0b Set to 1 to enable stutter mode