NCR 7600 - Power Management

14 Product Overview
Power Management
TheBIOSsupportstheAdvancedConfigurationandPowerManagementInterface
(ACPI)2.0specification.AkeyfeatureofACPIisthattheoperatingsystem,notthe
BIOS,configuresandimplementspowermanagement.The7600terminalsupportsthe
GlobalsystempowerstatesdefinedbyACPI:
G3 Mechanical Off
Acomputerstatethatisenteredandleftbyamechanicalmeans
Example: Turningoffthesystemʹspowerthroughthemovementofalargeredswitch.
Variousgovernmentagenciesandcountriesrequirethisoperatingmode.Itisimplied
bytheentryofthisoffstatethroughamechanicalmeansthat
noelectricalcurrentis
runningthroughthecircuitryandthatitcanbeworkedonwithoutdamagingthe
hardwareorendangeringservicepersonnel.TheOSmustberestartedtoreturntothe
Workingstate.Nohardwarecontextisretained.Exceptforthereal‐timeclock,power
consumptioniszero.
G2/S5 Soft Off
Acomputerstatewherethecomputerconsumesaminimalamountofpower.Nouser
modeorsystemmodecodeisrun.Thisstaterequiresalargelatencyinordertoreturn
totheWorkingstate.Thesystemʹscontextwillnotbepreservedbythehardware.The
systemmustberestarted
toreturntotheWorkingstate.Itisnotsafetodisassemblethe
machineinthisstate.
G1 Sleeping
Acomputerstatewherethecomputerconsumesasmallamountofpower,usermode
threadsarenotbeingexecuted,andthesystemappearstobeoff(fromanenduserʹs
perspective,thedisplayisoff,andsoon).LatencyforreturningtotheWorkingstate
variesonthewakeenvironment
selectedpriortoentryofthisstate(forexample,
whetherthesystemshouldanswerphonecalls).Workcanberesumedwithout
rebootingtheOSbecauselargeelementsofsystemcontextaresavedbythehardware
andtherestbysystemsoftware.Itisnotsafetodisassemblethemachinein
thisstate.
G0 Working
Acomputerstatewherethesystemdispatchesusermode(application)threadsand
theyexecute.Inthisstate,peripheraldevices(peripherals)arehavingtheirpowerstate
changeddynamically.Theusercanselect,throughsomeUI,variousperformance/
powercharacteristicsofthesystemtohavethesoftwareoptimizeforperformanceor
batterylife.
Thesystemrespondstoexternaleventsinrealtime.Itisnotsafeto
disassemblethemachineinthisstate.