24
Chapter 1
Power Management
NOTE:
The VGA BIOS should support DPMS (Desktop Power Management System) for the standby and suspend mode
function call. When the Display Standby Timer expires, the system BIOS will execute the DPMS service routines.
Power Saving Mode Phenomenon List
Power Saving Mode
Phenomenon
Device Standby mode
T
Independent power management timer for HDD devices (0-15
minutes, time step = 1 minute)
T
Hard disk drive goes into STANDBY mode (for ATA standard
interface)
T
Disable V-sync to control the VESA DPMS monitor
T
Resume method: device activated (keyboard for DOS, keyboard &
mouse for Windows)
T
Resume recovery time: 3-5 seconds
Global Standby mode
T
Global power management timer (1-60 minutes)
T
Hard disk drive goes into STANDBY mode (for ATA standard
interface)
T
Disable H-sync and V-sync signals to control the VESA DPMS
monitor
T
Resume recovery time: 7-10 seconds
System Suspend mode
T
Independent power management timer (1-60 minutes) or pushing
external switch button
T
CPU goes into SMM (System Management Mode)
T
CPU asserts STPCLK# and goes into the Stop Grant State
T
LED on the panel flashes in amber color
T
Hard Disk Drive goes into SLEEP mode (for ATA standard
interface)
T
Disable H-sync and V-sync signals to control the VESA DPMS
monitor
T
Return to original state by pushing external switch button.
