usb_20中英文pdf.rar

两个文档： 1.usb_20.pdf ObjectiveoftheSpecification Thisdocumentdefinesanindustry-standardUSB.Thespecificationdescribesthebusattributes,theprotocoldefinition,typesoftransactions,busmanagement,andtheprogramminginterfacerequiredtodesignandbuildsystemsandperipheralsthatar