Specifications

1-28 Chapter 1: 7401-2xxx/3xxx Product Overview

ACPIprovidessimilarmodesofoperationasAPM.The7401hardware
supportsfourPowerManagementStates.
State Characteristics
OFF ACpowerisnotpresent.AllRAMcontentsarelost.
ON
 APMAuto
state
 ACPIG0/S0
Workingstate
Powerisonandfullysuppliedtoall7401components.Thedisplayand
touchpanelareactive.TheCPUmaybefullyonorbeinchipstandbymode.
Thisistransparenttotheuserandtheapplication.Standbymodereduces

powerrequirementsandiscontrolledbythechipsetandisentered/exited
dependingontheCPU’sutilizationlevel.Transitioningbetweenfullyon
andstandbycausesnodelay.
CONSERVE
 APMStandby
state
 ACPIG1/S1
Sleepingstate
Powerison,butconsumptionisreducedbythrottlingbackorcompletely
stoppingthesystemclock.Throttlingisfullyprogrammable.Thisisthe
primarymeansofreducingsystempowerconsumptionandisusedtohelp
correctahightemperaturewarninglevel
detectedbythetemperature
monitor.TemperaturemayalsobereducedbydimmingtheLCD.Thereis
nouserorapplicationactionrequiredforthismode.WhenaSafe
Temperatureisdetected,thesystemswitchesbacktotheONstate.
TransitioningbetweenONandCONSERVEtakeslessthan10milliseconds.
SOFTOFF
 APMSuspend
State
 ACPIG2/S5
SoftOffstate
Temperaturehasreachedacriticallyhighlevel,aLAN‐basedPowerdownwas
received,orasystemShutdownoccurred.Powerconsumptionisreduced
toitslowestlevel.Allvoltagesarestillpresent,butBIOSplaceseach
peripheralandchipinto
itslowestavailablepowerstate.Thechipsetenters
theSuspend‐to‐RAMmode.TheLCDbacklightisturnedoff,blankingthe
display.RAMcontentsarepreserveduponreturntoONstateunless
softwareissuesareset.IfthisstatewasenteredbecauseofaLAN‐based
Powerdownor
systemShutdown,transitioningtotheONstatecanoccurvia
LAN‐basedresetorwakeup,Timerwake‐up,Touchactivity,Motion
Sensor,orkeyboard.IfSOFTOFFwasenteredbecauseofaCritical
Temperature,theONstatecanbeautomaticallytransitionedtowhenaSafe
Temperatureisreached.