单片机最小系统资料

课程设计（论文）课程名称：电子CAD课程题目名称：单片机最小系统的PCB设计专业：班级：学号：姓名：该目录仅供参考，请根据自己的情况酌情加、删前言PROTEL99SE简介单片机最小系统原理图介绍印制电路板PCB介绍单片机最小系统电路的PCB设计过程（详细步骤）元件明细表原理图PCB板图结论结束语参考文献PCB设计的一般流程原理图设计配置PCB编辑环境对元件进行布局引入网络表规划电路板PCB布线规则检查导出PCB文件以及打印AT89C51电源模块复位电路振荡电路蜂鸣器电路八段数码管显示电路按键电路RS232串口电路单片机最小系统原理图介绍要想让单片机正常工作则必须给单片机提供必要的外围电路，电源电路为其提供能量，振荡电路为其内部寄存器提供必要的时钟信号，复位电路让单片机从初始状态工作，这些都是单片机正常工作所必不可少的。而蜂鸣器电路、按键电路、八段数码管显示电路等外围电路则丰富了单片机的扩展功能，RS232串口电路为单片机程序的下载提供了串口。原理图包括八部分：AT89C51、4×4矩阵键盘、二位8段LED显示、复位电路、时钟电路、电源模块、蜂鸣器电路、串口通信电路。单片机AT89C51芯片：89C51是一种带4K字节闪烁可编程可擦除只读存储器（FPEROM—FalshProgrammableandErasableReadOnlyMemory）的低电压，高性能CMOS8位微处理器，俗称单片机。特点：有40个引；8位CPU；片内振荡器和时钟电路；32根I/O线；外部存贮器寻址范围ROM、1234ABCD4321DCBATitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:XTAL1XTAL2RESET9RXD10INT012INT113T114T015EA/VP31XTAL119P0.039P0.138P0.237P0.336P0.435P0.534P0.633P0.732P1.01P1.12P1.23P1.34P1.45P1.56P1.67P1.78P2.021P2.122P2.223P2.324P2.425P2.526P2.627P2.728ALE/P30TXD11WR16RD17PSEN29XTAL218GND20Vcc40AT89C51U3AT89C51VCCVCCP0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.7P2.4P2.5P1.1P1.2P1.3P1.4P1.5P1.6RESETP1.0P2.7RXDTXDC8104RAM64K；2个16位的定时器/计数器；5个中断源，两个中断优先级；全双工串行口；布尔处理器；电源模块：单片机供电采用7805三端线性稳压芯片配合直流稳压电源构成。直流1234ABCD4321DCBATitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:R2100KC71uFS1SW-PBVCCRESET输入低于18V的直流电，输出为5V（误差小于5%），led发光指示，完全满足单片机及其他芯片的要求。TitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:12J1CON2D1DIODED2DIODED3DIODED4DIODEC1104C2104+C3470uF+C4470uFR11KD5LED132VVGNDINOUTU1LM7805VCC复位电路和时钟电路：复位电路和时钟电路是维持单片机最小系统运行的基本模块。复位电路通常分为两种：上电复位和手动复位。AT89C51系列单片机为高电平复位，在复位引脚RST上接一电容到VCC，再接一电阻到GND,由此形成一个RC充放电路，RST单片机C1R1GNDVCC上电复位手动复位合适频率的晶振对于选频信号强度准确度都有好处，振荡电路由一个12MHz的晶振和两个电容所组成，陶瓷电容帮助起振。4×4矩阵键盘电路：1234ABCD4321DCBATitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:C530pFC630pFY112MHzXTAL1XTAL2时钟电路1234ABCD4321DCBATitleNumberRevisionSizeA4Date:19-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:R5RES2R4RES2R6RES2R3RES2VCCS2SW-PBS3SW-PBS4SW-PBS5SW-PBS6SW-PBS7SW-PBS8SW-PBS9SW-PB按键电路P1.1P1.2P1.3P1.4P1.5P1.6S10SW-PBS11SW-PBS12SW-PBS13SW-PBS14SW-PBS15SW-PBS16SW-PBS17SW-PBP1.7P1.0以四条I/O线作为行线，四条I/O线作为列线组成的键盘。在行线和列线的每个交叉点上设置一个按键，这样键盘上按键的个数就是4*4个。这种行列式键盘结构有效的提高单片机系统I/O口的利用率。1234ABCD4321DCBATitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:P0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.712345678161514131211109RP1RESPACK4abfcgdeDPY1234567abcdefg8dpdpEN9DS1DPY_7-SEG_DPabfcgdeDPY1234567abcdefg8dpdpEN9DS2DPY_7-SEG_DPX1X2显示电路数码管显示电路：LED数码管显示是利用半导体发光制成条形的发光二极管，封装在一起组成数字或其他符号形状。数码管根据公共端不同，分为共阴极和共阳极两种形式。1234ABCD4321DCBATitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:R101KR111KR121KR131KR141KR151KR161KR171KVCCP0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.71234ABCD4321DCBATitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:Q2NPNQ3NPNR81KR91KP2.4P2.5X1X21234ABCD4321DCBATitleNumberRevisionSizeA4Date:18-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:R182KB1BELLQ1PNPVCCP2.7蜂鸣器控制数码管显示不同的数值电路P0口上拉电阻电路蜂鸣器电路：蜂鸣器电路用一个三极管驱动一个蜂鸣器。RS232串口电路：1234ABCD4321DCBATitleNumberRevisionSizeA4Date:19-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:162738495J2DB9C90.1uC100.1uRXDT2OUTT2OUTR2INR2INTXDRS通信协议VCCR1IN13R2IN8T1IN11T2IN10R1OUT12R2OUT9T1OUT14T2OUT7C1+1C1-3C2+4C2-5U2MAX232ACPE(16)RS232串口电路使用MAX232CPE作为电平转换芯片，并通过套件提供的串口电缆连接到计算机背后的COM口（9针D型口），用于MCS51LITE与上位机通信以及和其他串口设备的数据交互。1234ABCD4321DCBATitleNumberRevisionSizeA4Date:19-Nov-2011SheetofFile:C:\DocumentsandSettings\Administrator\桌面\MyDesign.ddbDrawnBy:C530pFC630pFY112MHzR5RES2R4RES2R6RES2R3RES2XTAL1XTAL1XTAL2XTAL2RESET9RXD10INT012INT113T114T015EA/VP31XTAL119P0.039P0.138P0.237P0.336P0.435P0.534P0.633P0.732P1.01P1.12P1.23P1.34P1.45P1.56P1.67P1.78P2.021P2.122P2.223P2.324P2.425P2.526P2.627P2.728ALE/P30TXD11WR16RD17PSEN29XTAL218GND20Vcc40AT89C51U3AT89C51VCCVCCR2100KC71uFS1SW-PBVCCP0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.7P0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.712345678161514131211109RP1RESPACK4R182KabfcgdeDPY1234567abcdefg8dpdpEN9DS1DPY_7-SEG_DPabfcgdeDPY1234567abcdefg8dpdpEN9DS2DPY_7-SEG_DPB1BELLQ1PNPVCCR101KR111KR121KR131KR141KR151KR161KR171KVCCP0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.7Q2NPNQ3NPNR81KR91KP2.4P2.5X1X2X1X2S2SW-PBS3SW-PBS4SW-PBS5SW-PBS6SW-PBS7SW-PBS8SW-PBS9SW-PBVCCP2.4P2.5复位电路按键电路上拉电阻电路时钟电路显示电路控制显示电路P1.1P1.2P1.3P1.4P1.5P1.6P1.1P1.2P1.3P1.4P1.5P1.6单片机最小系统1白银矿冶技术学院RESETRESET12J1CON2D1DIODED2DIODED3DIODED4DIODEC1104C2104+C3470uF+C4470uFR11KD5LED132VVGNDINOUTU1LM7805VCCP1.0P2.7P2.7162738495J2DB9C90.1uC100.1uRXDRXDT2OUTT2OUTR2INR2INTXDTXDC8104RS通信协议VCC蜂鸣器供电电路101S10SW-PBS11SW-PBS12SW-PBS13SW-PBS14SW-PBS15SW-PBS16SW-PBS17SW-PBP1.7P1.7P1.0R1IN13R2IN8T1IN11T2IN10R1OUT12R2OUT9T1OUT14T2OUT7C1+1C1-3C2+4C2-5