逻辑供电的串行EEPROM

Embeddedapplicationsincreasinglywantmore

integrationandpower,inlessspaceforlesscost.Using

lowpowerSerialEEPROMs(SEE)forapplication

firmware,lookuptables,andmicrocodecoupledwith

smallfootprintsmakesforpermanentstorageat

respectablesavings.Oneadditionalmethodofsaving

onthepowerbudgetisselectivelypoweringoff

componentswhennotneeded,abasicforembedded

powermanagement.Thelow-powerSEEsofferedby

MicrochipTechnologyInc.,offeranadditionalbenefit,

poweringtheSEEfromamicrocontrollerport.This

allowsthehostcontrollertonotonlymanipulatethe

SerialEEPROMReadsandWrite,butalsotheperiods

whenitispoweredofforon.Satellitecommunications

usethistechniquetosavepowerandtotaldose

accumulation.WecallthistechniquePOWERPORT

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.

ThemicrocontrollerportmusthavesufficientIoh

(sourcecurrent)tosustainthevoltageandcurrentfor

allmemoryfunctions,READ,ERASE,andWRITE.

Obviously,notallmemoryorperipheraldevicescould

bepoweredthusly,butMicrochip’sSEEdeviceswill

functioninthisenvironment.AN535LogicPoweredSerialEEPROMsAuthore:RichardJ.FisherParameterConditionsMicrochipTechnologyInc.BruceNegleyICCSTANDBYNotinanactiveoperationwhileMicrochipTechnolgyInc.VCCissupplied.ICCREADThepartisinaREADoperation.EmbeddedapplicationsincreasinglywantmoreICCPEAKTheBYTE/PAGEWRITEandintegrationandpower,inlessspaceforlesscost.UsingWRITEERAS