使用PIC16C5X智能IIC外设

INTRODUCTION

PIC16C5XmicrocontrollersfromMicrochipareideally

suitedforuseassmartperipheraldevicesunderthecon-

trolofthemainprocessorsinsystems,duetotheirlow

costandhighspeed.Theyarecapableofperforming

taskswhichwouldsimplyoverloadaconventionalmicro-

processor,orrequireconsiderablelogiccircuitry,ata

costcompetitivewithlowermid-rangePLDs.Tominimize

theengineeringoverheadofaddingmultiplecontrollers

toaproduct,itisconvenientfortheauxiliarycontrollers

toemulatestandardI/Operipherals.

AcommoninterfacefoundinexistingproductsistheI

2

C

bus.Thisefficient,two-wire,bi-directionalinterface

allowsthedesignertoconnectmultipledevicestogether,

withthemicroprocessorabletosenddatatoandreceive

datafromanydeviceonthebus.Thisinterfaceisfound

onavarietyofcomponents,suchasPLLs,DACs,video

controllers,andEEPROMs.Ifaproductalreadycontains

oneormoreI

2

Cdevices,itissimpletoaddaPIC16C5X

emulatingacompatiblecomponent.

Thisapplicationnotedescribestheimplementationofa

standardslavedevicewithmultiple,bi-directional

registers.AsubsetofthefullI

2

Cspecificationis

supported,whichcanbecontrolledbythesame

softwarewhichwouldtalktoaMicrochip24LCXX

seriesEEPROM.AN541UsingaPIC16C5XasaSmartI2CPeripheralFIGURE1:I2CTIMINGAuthor:DonLekeiNIINorsatInternationalInc.SCLINTRODUCTIONSDAPIC16C5XmicrocontrollersfromMicrochipareideallysuitedforuseassmartperipheraldevicesunderthecon-trolofthemainprocessorsinsystems,duetotheirlowtSHtCLtCHcostandhighspeed.Theyarecapableofperformingtaskswhichwouldsimplyoverloadaconventionalmicro-