标签: 基于pc

摘要：本文介绍了一个基于PC的示波器参考设计。重点介绍了MAX1393ADC和MAX1396EV(评估)板，文中给出了电路图、软件及软件功能说明。基于PC的示波器参考设计GordonLeeJan24,2010摘要：本文介绍了一个基于PC的示波器参考设计。重点介绍了MAX1393ADC和MAX1396EV(评估)板，文中给出了电路图、软件及软件功能说明。引言本参考设计提供了构建一个示波器所需的全部电路(图1)，设计采用MAX1396EVKIT(参考设计要求用MAX1393ETBADC替代MAX1396ETBADC)和一台PC，并提供了电路图、Windows软件和微控制器固件。固件示例程序采用C语言编写，利用IAREmbeddedWorkbench平台针对MAXQ2000进行编译，可免费下载MAXQ1.13C，4KKickStart版本的IAREmbeddedWorkbench。图1.基于PC的示波器MAX1393简介MAX1393为单通道、312.5ksps、真差分、12位SARADC。本参考设计采用MAX1393对输入波形进行采样。硬件简介MAX1396EVKIT包括MAX1396ADC(本设计中将其替换为MAX1393)、MAXQ2000微控制器、所有必需的无源元件以及经过验证的PCB布局。MAX1396EVKIT原理图如图2所示。MAX1396EVKIT的电路板上没有安装MAX1393，可通过Maxim网站订购MAX1393ETB的样品，替换评估板上的MAX1396ETB。表1列出了所需的跳线设置。详细电路图(PDF,19kB)图2.MAX1396EVKIT原理图表1.跳线设置JumperPositionJU11-2JU21-2JU31-2JU41-2JU51-2JU6……

ThisapplicationnotedescribestheconstructionofalowcostserialprogrammerwhichusesaPCwithapar-allel(Centronixprinter)porttocontrolaPIC16C84.ThisprogrammerhasthecapabilityofprogrammingaPIC16C84microcontroller,andreadingbackinternaldatawithoutremovingthedevicefromthetargetcircuit.Thisfeatureisveryusefulinapplicationswherechangesinprogramcodeorprogramconstantsarenecessarytocompensateforothersystemfeatures.Forexample,anembeddedcontrolsystemmayhavetocompensateforvariancesinamechanicalactuator’sperformanceorloading.Thebasicprogramcanbepro-grammedandtestedduringdesignphase.Thefinalprogramandcontrolconstantscanbeeasilyaddedlaterintheproductionphasewithoutremovingthemicrocontrollerfromthecircuit.Automaticsoftwareandperformanceupgradescanalsobeimplementedin-system.Uponreceivingnewsystemsoftwareviadiskormodem,acontrolprocessorwiththeincludedprogrammingcodecouldperformin-circuitreprogrammingofothermicrocontrollersinthesystem.Thisprogrammercanloadprogramcode,partconfiguration,andEEPROMdataintothePIC16C84.Inreadbackmode,itcanverifyalldataentries.MAPC-BasedDevelopmentProgrammerforthePIC16C84AN589Afterenteringprogrammingmode,RB7isusedtoAuthor:RobertSpurseriallyenterprogrammingmodesanddataintotheAnalogDesignSpecialist,Inc.part.AhightolowtransitiononRB6,theclockinput,qualieseachbitofthedataappliedonRB7.PleaseINTRODUCTIONrefertothePIC16C84ProgrammingSpecication(DS30189)fordetailsonthegures.Th……