介绍apm bios接口（ppt53(1)复习进程.ppt

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1、介绍APMBIOS接口（PPT53）(1)1.APMIntroduction1.1APMOverview1.2APMSystem1.3Terms7/29/202121.1APMOverviewWhatisAPM?APM(advancedpowermanagement)isdefinedbyIntelandMicrosoftCorpin1992.Thelatestversionis1.2.FunctionofAPM:ControlthedevicepowersatethroughBIOS.APMVSACPI:InACPIenvironmentOScontrolalldevice’spower

2、stateandtheBIOSprovidesysteminformationonly.7/29/202131.2APMSystem7/29/202141.2APMSystemAPMBIOSisthesoftwareinterfacetothemotherboardanditspowermanageddevices.APMdrivermoduleconnectstotheAPMBIOSandcommunicatewiththeAPM-awareapplication.APM-awareDeviceDrivermodulesprovidesthesoftwareinterfaceforadd

3、-indevices.APM-awareApplicationsinterfacewiththeAPMdrivertomonitorandcontrolpowermanagement7/29/202151.3TermsAdd-inDeviceisnotonthemotherboard.APMConnectionisaprotocolandmechanismbywhichanAPMDriverandanAPMBIOSintercommunicate.CPUCOREincludestheCPUclock,cache,systembus,andsystemtimers.Resumetimeris

4、asystemtimerusedtowakeupthesystemfromalowpowerstateataspecifiedtime.SystemIdleisainactivestate.7/29/202162.1SystemPowerState2.2DeviceControl2.3CPUControl2.4SystemPowerStateTransition2.APMModel7/29/202172.1SystemPowerStates2.1.1FullOnState2.1.2APMEnableState2.1.3APMStandby2.1.4APMSuspend2.1.5OffSta

5、te7/29/202182.1.1FullOnStateTheFullOnStateisthedefaultmode.Systemisonworking.Systemisnotpowermanaged.Alldeviceareon.7/29/202192.1.2APMEnableStateIntheAPMEnableStatethesystemisdoingworkbutsomeunuseddevicesmaynotbepowered.TheCPUclockisslowedorstoppedanddevicesarepowermanagedasneeded.7/29/2021102.1.3

6、APMStandbyThesystementerstheAPMStandbyStateafterashortperiodinactivity.Thesystemisinalowpowerstatewithsomepowersavings.Mostdeviceareinalowpowermode.TheCPUclockisslowedorstopped.SystemreturnsquicklytotheAPMEnableState.Interruptsmuststillbeprocessednormally.7/29/2021112.1.4APMSuspendThesystementerth

7、eAPMSuspendStateafterarelativelylongperiodofinactivity.SystemtakesarelativelongtimetoreturntotheAPMEnableState.SystemisnotworkingandinalowpowerstatewithmaximumpowersavingsMostpowermanageddevicearenotpoweredTheCPU