英语翻译Inmostmoderncomputersmainmemoryisvolatilewhichmeansthatitloosesitsmemorywhenthepowerisremoved.Memoryisdividedintomanyidenticalstoragecells.Eachcellcontainsafixednumberofbits.Eightbitcellsarecalledbyte
英语翻译
Inmostmoderncomputersmainmemoryisvolatilewhichmeansthatitloosesitsmemorywhenthepowerisremoved.
Memoryisdividedintomanyidenticalstoragecells.
Eachcellcontainsafixednumberofbits.
Eightbitcellsarecalledbytes.
Eachstoragecellisgivenauniqueaddress,whichiscalledthecell'slocation
ACPUonlyhastwowaystoaccessamemorylocation,suchasReadandWrite.
TheI/OSubsystemprovidesaconsistentlinktothemanyI/Odevicesattachedtothecomputersystem
ACPUaccessesdevicesviaI/Oports.
TherearetwocomputerdesigntechniquesusedforaccessingI/Oports:
Accesstheportasamemoryaddress.CPUsthatimplementthistechniquereserveaspecialrangeofmemoryaddressesforI/Oports.
Useaseparateaddressingmechanism.CPUsthatreserveaseparateaddressspaceforI/Oportsmustusespecialinstructionsforaccessingtheports.
谢谢两位的诚恳回答