使用Microchip的USB设备固件实现大容量存储设备

INTRODUCTION

USBdevicesarenowpartadailylifeformanypeople

throughouttheworld.RemovableUSBharddrives,

USBmemorysticks(“thumbdrives”),multi-card

readersandmanydigitalcamerasappearasanew

diskdrivewhentheyarepluggedintotheUSBportof

acomputer.ThesedevicesallusetheMassStorage

Device(MSD)classtocommunicatewiththecomputer.

Thisapplicationnotewillcoverhowtomodifythe

MicrochipUSBDeviceFirmwareFrameworktocreate

aMassStorageDevice.Itisassumedthattheuser

alreadyhassomeworkingknowledgeoftheUSB

protocol.AN1189ImplementingaMassStorageDeviceUsingtheMicrochipUSBDeviceFirmwareFrameworkTheCBWistransmittedontheUSBasthefirstpacketAuthor:DavidFlowersMicrochipTechnologyInc.ofanewtransaction.Itdefineswhatcommandisbeingtransmitted,whatthelengthis,whichlogicaldeviceisbeingtalkedtoandatagtohelptiethecommandtoaINTRODUCTIONstatusstage.USBdevicesarenowpartadailylifefor