FW82801BASL5PN Datasheet, PDF (146/671 Pages) Intel Corporation – Intel® 82801EB I/O Controller Hub 5 (ICH5) / Intel® 82801ER I/O Controller Hub 5 R (ICH5R)

Functional Description
5.13 Power Management (D31:F0)
5.13.1
Features
• ACPI Power and Thermal Management Support
— ACPI 24-Bit Timer
— Software initiated throttling of processor performance for Thermal and Power Reduction
— Hardware Override to throttle processor performance if system too hot
— SCI and SMI# Generation
• PCI PME# signal for Wake Up from Low-Power states
• System Sleeping State Control
— ACPI S1 state: Stop Grant or Quickstart state (using STPCLK# signal) halts processor’s
instruction stream (only STPCLK# active, and SLP# optional)
— ACPI S3 state — Suspend to RAM (STR)
— ACPI S4 state — Suspend-to-Disk (STD)
— ACPI G2/S5 state — Soft Off (SOFF)
— Power Failure Detection and Recovery
• Streamlined Legacy Power Management Support for APM-Based Systems
5.13.2 Intel^® ICH5 and System Power States
Table 59 shows the power states defined for ICH5-based platforms. The state names generally
match the corresponding ACPI states.
Table 59. General Power States for Systems Using Intel^® ICH5
State/
Substates
G0/S0/C0
G0/S0/C1
G1/S1
G1/S3
G1/S4
G2/S5
G3
Legacy Name / Description
Full On: Processor operating. Individual devices may be shut down to save power. The
different processor operating levels are defined by Cx states, as shown in Table 60. Within
the C0 state, the Intel^® ICH5 can throttle the STPCLK# signal to reduce power consumption.
The throttling can be initiated by software or by the THRM# input signal.
Auto-Halt: Processor has executed a AutoHalt instruction and is not executing code. The
processor snoops the bus and maintains cache coherency.
Stop-Grant: ICH5 also has the option to assert the CPUSLP# signal to further reduce
processor power consumption.
Note: The behavior for this state is slightly different when supporting iA64 processors.
Suspend-To-RAM (STR): The system context is maintained in system DRAM, but power is
shut off to non-critical circuits. Memory is retained, and refreshes continue. All clocks stop
except RTC clock.
Suspend-To-Disk (STD): The context of the system is maintained on the disk. All power is
then shut off to the system except for the logic required to resume.
Soft Off (SOFF): System context is not maintained. All power is shut off except for the logic
required to restart. A full boot is required when waking.
Mechanical OFF (MOFF): System context not maintained. All power is shut off except for
the RTC. No “Wake” events are possible, because the system does not have any power. This
state occurs if the user removes the batteries, turns off a mechanical switch, or if the system
power supply is at a level that is insufficient to power the “waking” logic. When system power
returns, transition will depends on the state just prior to the entry to G3 and the AFTERG3 bit
in the GEN_PMCON3 register (D31:F0, offset A4). Refer to Table 66 for more details.
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Intel^® 82801EB ICH5 / 82801ER ICH5R Datasheet