10 power management – MiTAC 7521 PLUS/N User Manual
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7521
7521
Plus / N N/B MAINTENANCE
Plus / 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
G0~G3 : Global power states
S0~S5 : System power states
B0~B3 : Bus power states
C0~C3 : Processor power states
D0~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