JG82852GMSL7VP Datasheet, PDF (144/176 Pages) Intel Corporation – Intel® 852GM/852GMV Chipset Intel® 852GM/852GMV Chipset Hub (GMCH)

Power and Thermal Management
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6.1.
6.2.
General Description of Supported CPU States
C0 (Full On): This is the only state that runs software. All clocks are running, STPCLK is deasserted,
and the processor core is active. The processor can service snoops and maintain cache coherency in this
state.
C1 (Auto Halt): The first level of power reduction occurs when the processor executes an Auto-Halt
instruction. This stops the execution of the instruction stream and reduces the processor’s power
consumption. The processor can service snoops and maintain cache coherency in this state.
C2 (Stop Grant): To enter this low power state, STPCLK is asserted. The processor can still service
snoops and maintain cache coherency in this state.
C3 (Sleep or Deep Sleep): In these states the processor clock is stopped. The GMCH assumes that no
Hub Interface cycles (except special cycles) will occur while the GMCH is in this state. The processor
cannot snoop its caches to maintain coherency while in the C3 state. The GMCH will transition from the
C0 state to the C3 state when software reads the Level 3 Register. This is an ACPI defined register but
BIOS or APM (via BIOS) can use this facility when entering a low power state. The Host Clock PLL
within the GMCH can be programmed to be shut off for increased power savings and the GMCH uses
the DPSLP signal input for this purpose.
C4 (Deeper Sleep): The C4 state appears to the GMCH as identical to the C3 state, but in this state the
processor core voltage is lowered. There are no internal events in GMCH for the C4 state that differ
from the C3 state (this state is not supported for Intel Celeron M processor and mobile Intel Celeron
processor).
General Description of ACPI States
Internal Graphics Adapter:
D0 Full on, display active
D1 Low power state, low latency recovery. No display, System Memory retained
D3 Hot - All state lost other than PCI config. System Memory lost (optionally)
D3 Cold - Power off
CPU:
C0 Full On
C1 Auto Halt
C2 DesktopStop Clock. Clk to CPU still running. Clock stopped to CPU core.
C3 Deep Sleep. Clock to CPU stopped.
C4 Deeper Sleep. Same as C3 with reduced voltage on the CPU.
System States
•G0/S0 Full On
•G1/S1-M Power On Suspend (POS). System Context Preserved
•G1/S2 Not supported.
•G1/S3 Suspend to RAM (STR). Power and context lost to chipset.
•G1/S4 Suspend to Disk (STD). All power lost (except wakeup on ICH4-M)
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Intel^® 852GM/852GMV Chipset GMCH Datasheet