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
.
ThemicrocontrollerportmusthavesufficientIoh
(sourcecurrent)tosustainthevoltageandcurrentfor
allmemoryfunctions,READ,ERASE,andWRITE.
Obviously,notallmemoryorperipheraldevicescould
bepoweredthusly,butMicrochip’sSEEdeviceswill
functioninthisenvironment.AN535LogicPoweredSerialEEPROMsAuthore:RichardJ.FisherParameterConditionsMicrochipTechnologyInc.BruceNegleyICCSTANDBYNotinanactiveoperationwhileMicrochipTechnolgyInc.VCCissupplied.ICCREADThepartisinaREADoperation.EmbeddedapplicationsincreasinglywantmoreICCPEAKTheBYTE/PAGEWRITEandintegrationandpower,inlessspaceforlesscost.UsingWRITEERAS