计算机专业翻译关于设备总线控制DeviceControlviaBusesNotalldevicesareaddresseddirectlybyI/Ostatementsbutviaabussystem.Howthisisdonevariesaccordingtothebusanddevicesused.Ratherthangoingintospecificdetai
计算机专业翻译关于设备总线控制
DeviceControlviaBuses
NotalldevicesareaddresseddirectlybyI/Ostatementsbutviaabussystem.Howthisisdonevariesaccordingtothebusanddevicesused.Ratherthangoingintospecificdetails,Idescribethebasicdifferencesbetweenthevariousapproacheshere.
Notalldeviceclassescanbeattachedtoallbussystems.Forexample,itispossibletoconnectharddisksandCDwritersbutnotgraphiccardstoanSCSIinterface.However,thelattercanbehousedinPCIslots.
Incontrast,harddisksmustbeattachedtoaPCIbusviaanotherinterface(typicallyIDE).
Thedifferentbustypesarecalledsystemandexpansionbuses(Iwon’tbotherwiththeirtechnicaldetails).
Thedifferencesinhardwareimplementationarenotimportantforthekernel(andarethereforeofnorelevancewhenprogrammingdevicedrivers).Onlythewayinwhichthebusesandattachedperipheralsareaddressedisrelevant.