基于FPGA的LCD驱动设计与实现

摘要摘要随着FPGA技术的不断发展及其价格不断下降，基于FPGA的可编程逻辑器件设计的应用优势逐渐显现出来，现如今，越来越多的嵌入式系统选择了基于FPGA的设计方案。本课题的主要任务是设计基于FPGA的嵌入式LCD驱动，利用FPGA来控制在LCD上显示图像和字符信息。本次设计采用了两种可行方案来实现，第一种方案是采用基于VHDL描述的VGA显示控制器，通过FPGA控制VGA接口在LCD显示器上显示字符和图像。第二种方案是采用带ST7920驱动的12864-12液晶模块，并使用Xilinx公司的spartan3e系列的XC3S500E作为核心的控制器。控制器部分采用VHDL语言编写，主体程序采用了状态机作为主要控制方式。该控制器分为字符显示模块和图像显示模块两个主要部分。在字符的显示功能上采用显示控制模块与字符调用RAM相结合的方式，使使用者能方便地调用液晶自带的字库来显示字符；而图像显示模块则通过特殊的处理算法解决了图像显示缓冲区X地址不断移位以及上下半屏分开的问题，通过读取图像RAM来显示图像。最后实现使用FPGA在LCD上的任意位置显示任意的16*16像素的中文字符以及16*8的英文字符，另外要能将储存模块中的图像数据正常地显示在LCD上。关键词：FPGAVGALCDLCD12864VHDLABSTRACTABSTRACTAlongwiththeFPGAtechnologyunceasingdevelopmentandthepriceunceasingdrop，theapplicationsuperioritywhichdesignsbasedontheFPGAprogrammablelogicalcomponentappearsgraduallycomesout，now，moreandmoremanyembeddedsystemshavechosenbasedontheFPGAdesignproposal.ThistopicprimarymissionisthedesignbasedontheFPGAembeddedLCDactuation，controlsusingFPGAonLCDdemonstratesthepictureandthecharacterinformation.Thisdesignusedtwokindoffeasibleplanstorealize，thefirstkindofplanwasusesbasedonVHDLthedescriptionVGAdisplaycontrolswitch，controlledtheVGAconnectionthroughFPGAtodemonstratethecharacterandthegraphontheLCDmonitor.ThesecondkindofplanisuseshastheST7920actuation12864-12liquidcrystalmodule，andusesXilinxCorporationspartan3eseriesXC3S500Etotakethecorethecontroller.ThecontrollerpartusedtheVHDLlanguagecompilation，themainbodyprocedureusesthestatemachinetotaketheprimarycontrolway.Thiscontrollerdividesintothecharacterdisplaymoduleandthepicturedemonstrationmoduletwomainparts.UsesthedisplaycontrolmoduleandthecharacterinthecharacterdemonstrationfunctiontransfersthewaywhichRAMunifies，enablestheusertotransferliquidcrystalbringingthefontstodemonstratethecharacterconveniently;ButthepicturedemonstratedthemodulesolvedtheimagedisplaybufferXaddressthroughthespecialprocessingalgorithmunceasinglytoshiftaswellasabouthalfscreenseparatedquestion，demonstratedthepicturethroughreadpictureROM.FinallyrealizesusesFPGAontheLCDrandompositiondemonstrationrandom16*16pictureelementChinesecharacteraswellasthe16*8Englishcharacter，moreovermustbeabletostoreupinthemodulethepicturedatatodemonstratenormallyonLCD.Keywords:FPGAVGALCDLCD12864VHDL目录i目录第一章绪论.......................................................................................................................11.1选题的背景与意义...........................................................................................11.2国内外发展现状...............................................................................................21.3本课题主要研究内容.......................................................................................3第二章关键技术的介绍...................................................................................................52.1FPGA简介.......................................................................................................52.2LCD简介..........................................................................................................62.2.1VGA接口显示器LCD(TFT)................................................................72.2.2LCD12864-12(STN)...............................................................................72.3VGA简介.........................................................................................................72.3.1VGA概念及其接口...............................................................................72.3.2VGA显示原理.......................................................................................82.3.3VGA时序分析.....................................................................................11第三章VGA显示方案实现.......................................................................................133.1系统整体设计.................................................................................................133.2顶层控制模块.................................................................................................133.3二分频模块.....................................................................................................143.4时序控制模块.................................................................................................143.5RAM存储模块...............................................................................................163.6RAM读取控制模块.......................................................................................193.7系统仿真结果.................................................................................................193.8本章小结.........................................................................................................20第四章LCD12864简介.............................................................................................214.1外形尺寸和外部引脚.....................................................................................214.2接口电路设计.................................................................................................224.3接口时序（ST7920控制驱动器）...............................................................234.4编程指令..................................................................................