实现PIC18C601单片机的外部存储器接口

ThePIC18C601andPIC18C801aretheveryfirst

membersofMicrochip’sPIC18familythatareROM-

lessmicrocontrollers—thatis,theyhavenoon-chip

programmemory.BothoffertheenhancedPIC18

architecture,alongwiththeabilitytousedifferenttypes

andsizesofexternalprogrammemorytoexactlyfitany

application.Inadditiontostandard1.5Kbytesofgen-

eralpurposeRAM,thePIC18C601canaddressupto

256Kbytesofexternalprogrammemory,whilethe

PIC18C801canaddressupto2Mbytesofexternal

programmemory.Withthisamountofavailable

addressablespace,thePIC18C601/801devices

becomeidealcandidatesformorecomplexapplica-

tions(e.g.TCP/IPstacks),developedwithhighlevel

programminglanguages,suchas‘C’.AN778ImplementingtheExternalMemoryInterfaceonPIC18C601/801MCUsGiventhenumberandtypesofmemoriesavailableAuthor:GaurangKavaiyatoday,findingandinterfacingmemorytotheMicrochipTechnologyInc.PIC18C601/801devicespotentiallybecomesachal-lengingtask.ThisapplicationnotedescribesthePIC18C601/801externalmemory