标签: expander

Manyhigh-reliabilitysystemsmaintainabackupcopyoftheirflashmemoryshouldanewsoftwaredownloadbecomeunusableforanyreason.ThisapplicationnotedescribeshowtheDS4510,DS4520,andDS4550non-volatileI/Oexpanderscanbeusedtoselecttheproperpageofflashmemoryonsystempower-up.……

AcircuitconsistingofanSMBus™I/Oexpander,step-upconverter,anddigitalpotentiometerenablestheSMBustocontrolthecontrastofanLCD.……

【应用笔记】使用MAXII和MAX3000A器件扩展微控制器I/O口(UsingMAXII&MAX3000ADevicesasaMicrocontrollerI/OExpander)ManymicrocontrollerandmicroprocessorslimitI/Oportsandpinstoconservepincountsandreducepackagesizes.Formanymicrocontroller-(e.g.,PIC,8051,andSX)ormicroprocessor-basedsystems,thesystemdesignrequiresmoreI/Opinswithoutchangingthemicrocontroller.ToincreasethenumberofI/Opinswithoutchangingthemicrocontroller,I/Oexpansionprovidesasolution.Withupto272I/OpinsandMultiVoltTMI/Ocapability,Altera®MAX®IIandMAX3000AdevicesallowyoutoimplementmicrocontrollerI/Oexpansioninmicrocontroller-ormicroprocessorbasedsystems.ThisapplicationnoteexplainshowtoimplementamicrocontrollerI/OexpanderinMAXIIandMAX3000Adevices.UsingMAXII&MAX3000ADevicesasaMicrocontrollerI/OExpanderMarch2004,ver2.0ApplicationNote265IntroductionManymicrocontrollerandmicroprocessorslimitI/Oportsandpinstoconservepincountsandreducepackagesizes.Formanymicrocontroller-(e.g.,PIC,8051,andSX)ormicroprocessor-basedsystems,thesystemdesignrequiresmoreI/Opinswithoutchangingthemicrocontroller.ToincreasethenumberofI/Op……

摘要：除了减少所需的GPIO线从十一点到两个数量，该电路还提供了可编程的对比度和背光控制。Maxim>AppNotes>DisplayDriversKeywords:LCDdriver,opamp,I/Oportexpander,contrastcontrol,backlight-intensitycontrol,digital-to-Nov23,2005analogconverter,DACAPPLICATIONNOTE3658SerializinganHD44780LCDDisplayAbstract:BesidesreducingthenumberofrequiredGPIOlinesfromeleventotwo,thiscircuitalsoprovidesprogrammablecontrastandbacklightcontrol.MostLCDcharacterdisplaysconnecttotheoutsideworldthroughacontrollerIC,suchastheHD44780(Hitachi)orequivalent.Thatinterfacehasseriousdrawbacks,however.Itusesupalargenumberofthemicrocontroller'sgeneral-purposeinput/output(GPIO)pins,anditisn'tcapableofprovidingdigital-contrastorbacklight-intensitycontrol.ThecircuitinFigure1reducestherequirednumbero……