Acer Extensa 4120, Service Manual

Page: 135 / 143

Appendix C 125
Power Management
Item Specification
Power management standard ACPI 1.0b/2.0/3.0
System power management states
T
Mechanical Off (G3) – All system devices are turned off
completely.
T
Soft Off (G2/S5) – OS initiated shutdown. All devices
in the system are turned off completely.
T
Working (G0/S0) – Individual devices such as the
processor and hard disk may be power managed in
this state.
T
S3 Sleeping State
T
CPU set power down
T
VGA suspend
T
Audio power down
T
Hard disk power down
T
Optical drive power down
T
Card reader function suspend
T
S4 Sleeping State (hibernation mode) – All system
states and data are saved onto disk before power
shutdown. The same session is restored the next time
the system is powered on.
Processor power management states To further conserve power in a Working state, the
processor enters a low-power state when the OS is idle.
T
C1 state – CPU halt instruction
T
C2 state – CPU stop grant state
T
C3 state – CPU stop clock state
Acer TM 4520 SG.book Page 125 Friday, June 22, 2007 5:43 PM