Programmer’s Guide BCM5722
10/15/07
Broadcom Corporation
Document 5722-PG101-R Advanced Configuration and Power Interface Page 524
The OS Power Management (OSPM) is responsible for global power state transitions. A global state is a platform wide con-
figuration, which directs sleep and device power management state(s). The following global states are defined in the ACPI
2.0 specification (see Figure 78):
• G0 Working—The ACPI 2.0 specification defines the G0 state as follows:
”The normal operating environment of an ACPI machine. In this state, different devices are dynamically transitioning
between their respective power states (D0, D1, D2, D3).”
Essentially, the OSPM may throttle unused portions of the platform architecture to conserver power. The GO state is
synonymous with the Sleep State S0.
• G1 Sleeping—The G1state contains four substates (S1, S2, S3, S4). These substates are platform implementations of
different sleep modes. The depth and amount of power savings depends upon the sleep state (S1-S4), which the
platform implements.
• G2 Soft Off—The ACPI 2.0 specification defines the G2 state as follows:
“A computer state where the computer consumes a minimal amount of power.”
System context will not be preserved by hardware.
• G3 Mechanical Off—No power to system. It is safe to replace hardware. There should be zero power consumption.
Figure 78: OS Power Management (OSPM) Global States
G3
Mechanical
Off
G0
Working
G1
Sleeping
Legacy
G2
Soft Off
Sleep States
S1,S2,S3,S4
Sleep State
S0
Sleep State
S5
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