MiTAC 7521 PLUS/N service manual Concept, Acpi Power States, Summary of Global Power States

7521Plus / N N/B MAINTENANCE

1.2.10 POWER MANAGEMENT

ACPI Introdution

The system BIOS is conform with ACPI1.0B specification.

Concept

ACPI (Advanced Configuration and Power Interface) replaces APM and PnP functionality, it’s a Operating-System controlled Power Management and a subset of OnNow system.

The general behavior of a PC with OnNow is as follows:

‰Minimized or eliminated Startup and shutdown delays.

‰Both hardware and software can be made to trigger wake-up events.

‰The PC is perceived to be off when not in use but still capable of responding to wake-up events.

ACPI Power States

ƒG0~G3 : Global power states

ƒS0~S5 : System power states

ƒB0~B3 : Bus power states

ƒC0~C3 : Processor power states

ƒD0~D3 : Device power states

Summary of Global Power States

Global System	Software	Latency	Power Consumption	OS restart	Safe to disassemble	Exit state
State	Runs			required	computer	electronically
G0 - Working	Yes	0	Large	No	No	Yes
G1 - Sleeping	No	>0 varies with	Smaller	No	No	Yes
		sleep state
G2/S5-Soft off	No	Long	Very near 0	Yes	No	Yes
G3-Mechanical Off	No	Long	RTC battery	Yes	Yes	No	22