Chapter 1 25
Power Management Functions

Device Standby Mode

!Independent power management timer for hard disk drive devices
(0-15 minutes, time step=1 minute).
!Hard disk drive goes into Standby mode (for ATA standard interface).
!Disable V-sync to control the VESA DPMS monitor.
!Resume method: device activated (Keyboard for DOS, keyboard & mouse for Windows).
!Resume recovery time: 3-5 sec.

Global Standby Mode

!Global power management timer (2-120 minutes, time step=10 minut e).
!Hard disk drive goes into Standby mode (for ATA standard interface).
!Disable H-sync and V-sync signals to control the VESA DPMS monitor.
!Resume recovery time: 7-10 sec.

Suspend Mode

!Independent power management timer (2-120 minutes, time step=10 minutes) or pushing external
switch button
!CPU goes into SMM.
!CPU asserts STPCLK# and goes into the Stop Grant State.
!LED on the panel turns amber color.
!Hard disk drive goes into SLEEP mode (for ATA standard interface).
!Disable H-sync and V-sync signals to control the VESA DPMS monitor.
!Return to original state by pushing external switch button.

Suspend to RAM

!The system context is maintained in system memory
!Power is shut to non-critical circuits.
!Memory is retained, and refreshes continually.
!All clocks shut except RTC.
!Return to original state by pushing external switch button & “PME” events at ACPI mode.