用于PIC16和PIC18器件的FLASH引导程序

AmongthemanyfeaturesbuiltintoMicrochip’s

EnhancedFLASHMicrocontrollerdevicesisthecapa-

bilityoftheprogrammemorytoself-program.Thisvery

usefulfeaturehasbeendeliberatelyincludedtogive

theusertheabilitytoperformbootloadingoperations.

DeviceslikethePIC18F452aredesignedwithadesig-

nated“bootblock”,asmallsectionofprotectablepro-

grammemoryallocatedspecificallyforbootload

firmware.

Thisapplicationnotedemonstratesaverypowerful

bootloaderimplementationforthePIC16F87XAand

PIC18Ffamiliesofmicrocontrollers.Thecodingforthe

twodevicefamiliesisslightlydifferent;however,the

functionalityisessentiallythesame.Thegoalsofthis

implementationstressamaximumperformanceand

functionality,whilerequiringaminimumofcodespace.AN851AFLASHBootloaderforPIC16andPIC18DevicesAuthor:RossM.FoslerandFIGURE1:BOOTLOADERFUNCTIONALRodgerRicheyBLOCKDIAGRAMMicrochipTechnologyInc.BootloaderFirmwareRXTXINTRODUCTION