An Introduction to USB Descriptors

ThisTechnicalBriefdemonstratesthetranslationofa

gameportgamepadtoaUSBgamepadusingthe

PIC16C765,Microchip'slow-speedUSBPICmicro

®

microcontroller(MCU).ThepurposeofthisTechnical

Briefisnotonlytoshowthetranslationofagamepad

toUSB,butalsotoshowhowtosuccessfullydevelop

aUSBperipheralusingthePIC16C765.Anunder-

standingofUSBdescriptorsisthefoundationfor

successfulUSBperipheraldevelopment.TB054AnIntroductiontoUSBDescriptorswithaGamePorttoUSBGamePadTranslatorExampleUSBisamaster-slaveprotocol.Inotherwords,theAuthor:RestonCondithost(i.e.,PC)directsallcommunicationstoandfromMicrochipTechnologyInc.theperipherals.Peripheralsdonotsendinformationtothehostunlessthehostrequeststheinformation.HowdoesaperipheraltellthehostwhattypeofdeviceitisINTRODUCTION