AMD SB600 User Manual
Page 164

©2008 Advanced Micro Devices, Inc.
SMBus Module and ACPI Block (Device 20, Function 0)
AMD SB600 Register Reference Manual
Proprietary
Page 164
C4Control – RW – 8 bits – [PM_Reg:72h]
Field Name
Bits
Default
Description
DPRSLPVR_delay
6:0
000_0000b This defines the delay between CPU_STP# de-assertion and
DPRSLPVR de-assertion in C4 state, in 2us increment with
2us uncertainty.
C4ChkVgate
7
0b
1: check VGATE=1 before DPRSLPVR de-assertion
0: use DPRSLPVR_delay for DPRSLPVR de-assertion
C4Control register for the P4 system.
PopUpEndTime – RW – 8 bits – [PM_Reg:73h]
Field Name
Bits
Default
Description
PopUpEndTime
7:0
80h
This register applies to both P4 and K8 system. During C3/4
pop-up, SB monitors DMA traffic. If there has been no traffic
for PopUpEndTime, SB will bring system back to C3/4.
For P4 system, the time is counted by A-link clock.
For K8 system, the time is counted by OSC clock.
PopUpEndTime register
PwrFailShadow – RW – 8 bits – [PM_Reg:74h]
Field Name
Bits
Default
Description
PwrFailShadow
3:0
0h
Writing to these four bits will set the value onto bits [7:4].
Software should always set bit 2 = 1
PwrFailOption
5:4
00b
These two bits will determine how system should resume after
a power failure.
00: Use default: Wait for wake event to power up
01: Always on: always power on after power resumes
10: Always off: always power off after power resumes
11: Use previous: resume to same setting when power fails.
PowerState
6
0b
Power state indicator: 1 = on; 0 = off
ForcePwrOn
7
0b
If set and RTC AIE =1, will force power on after power
resumes regardless of Bit[5:4] setting; if cleared and RTC AIE
= 1, will wakeup when RTC alarm fires after a power
failure/resume.
PwrFailShadow register
Note: For ASIC revisions A11, A12, and A13 this register needs to be written twice for bits [7:4] to be updated
correctly. There is no such restriction with other revisions.
Tpreset1b – RW – 6 bits – [PM_Reg:75h]
Field Name
Bits
Default
Description
Tpreset1b
5:0
05h
Timing parameter used for S* -> S0 state transition.
This determines the delay between CPU_STP# de-assertion
and SUS_STAT# de-assertion, in 8us increment with 8us
uncertainty.
DelayRomRstEn
6
1b
1: 30ms ahead of deassertion of PciRst#
0: ROM_RST functions the same as PciRst#
DelayLanRstEn
7
1b
1: 20ms ahead of deassertion of PciRst#
0: Lan_RST functions the same as PciRst#
S0S3ToS5Enable0 – RW – 8 bits – [PM_Reg:76h]
Field Name
Bits
Default
Description
S0S3ToS5Enable0
7:0
FFh
This register determines which wakeup signals can be passed
onto the S5 region. For S4/S5 wake up, this bit must be set in
before the corresponding pin can be used
Bit [7:0]: GEVENT#[7:0]
1: Enable
0: Disable