单片机外文翻译----51系列单片机的结构和功能.doc

毕业设计(论文)外文资料翻译院（系）： 信息科学与技术学院 专 业： 电子信息科学与技术 姓 名： 学 号： 外文出处： from internet Structure and function of the MCS-51 series 附 件： 1.外文资料翻译译文；2.外文原文。完成日期： 2011 年 3月1 日 1. 外文资料翻译译文：51系列单片机的结构和功能51系列单片机是英特尔公司生产的具有一定结构和功能的单片机产品。这家公司在1976年引入8位MCS - 48系列单片机后，于1980年又推出了8位高档的MCS - 51系列单片机。它包含很多种这类型的单片机，如8051，8031，8751，80C51BH，80C31BH等，它们的基本组成，基本性能和指令系统都是一样的。一般情况习惯用8051来代表51系列单片机。一个单片机的系统是由以下几部分组成：（1）一个8位CPU微处理器。（2）静态随机存取存储器，能够储存程序运行过程中产生的数据。（3）程序存储器ROM / EPROM中（4KB/8KB），用来保存程序和一些初始数据。但是在一些单片机中不使用ROM / EPROM中，如8031，8032，80c系列等。（4）4个8排的I / O并行接口P0 P3，每个口可以用作输入，也可以用作输出。（5）2个定时器/计数器，每个定时器/计数器可设置计数用来计数外部事件，可以设置成常用的定时方式，并可以根据计算或结果控制单片机的运行。（6）五个中断源控制系统。（7）1个双向串行I / O口的UART（通用异步接收器/发送器UART），用于实现单片机的串行通信。（8）振荡器和时钟产生电路，需要外部电源的石英晶体微调电路，允许接在12v的振荡频率上。上述部分通过内部数据总线连接。其中，CPU是单片机的核心，它是单片机的控制和指挥中心，ALU算数逻辑运算单元可进行算术运算和逻辑运算，由1个 8暂时存储器，和2个 8位的累加器组成。Acc累加器是ALU运算结果的存放单元，一般数据通过它来传送。此外，Acc往往被视为对8051内的数据传输中转站。和通常的微处理器一样，它是最繁忙的寄存器。有记忆功能并执行命令。该控制器包括程序计数器，可读写的存储器，振荡器和定时电路等。该程序计数器是有两对8或16位计数器，它是一个字节地址计数器，在个人电脑运行程序时，执行下一个单元的内容，程序执行时可以改变它的内容从而改变运行的结果。在8051芯片震荡电路中，需要外接石英晶体和微调电容，其频率范围为1.2MHz12MHz。该脉冲信号，即为8051的工作周期，是最小的时间单位。8051和其他单片机一样，都有相同的控制和功能，就像乐队也有打击乐器一样。在8051中有ROM（程序存储器，只能读取），和RAM（数据存储器，可以读和写），他们有各自独立的内存地址空间，也有相同的处理方式。8051和8751的程序存储器的存储容量为4KB，地址从0000H开始，在使用过程中其中的数据不变。8051、8751、8031数据存储器的内存为128B，默认地址是00FH，用于保存中间数据和缓存。在这128B的内存中，有32 byteses，被称作工作寄存器，和常用的微处理器不同的是，8051的RAM是按功能来划分模块的。MCS - 51系列单片机和一般电脑的处理方式不同。一般电脑会自动分配地址空间，ROM和RAM的计算机可以安排在不同的空间内，地址范围会根据ROM和RAM的位置分配不同地址空间。在访问的内存，不管是ROM和RAM，只有一个地址对应一个内存单元，都要按这个顺序访问。这种内存结构是所谓的普林斯顿结构。 8051的存储器按物理结构划分可分为程序存储器空间和数据存储空间，共有四个内存空间，按结构位置的不同分为内部程序存储空间、外部程序存储空间、内部数据存储空间和外部数据存储空间。但从用户的使用角度看，8051存储器地址空间被分成三类：（1）片内，安排FFFFH的块，片外的（使用16个地址）串口0000H地址。（2）外部数据存储器地址空间为64KB，地址是从0000H到 FFFFH（含16个地址）的位置排列也。（3）256B的数据存储器（使用8个地址）的地址空间。上述三个重叠的内存空间地址，用8051指令系统的传输不同的数据和使用的功能区分。CPU的访问内存时，访问ROM使用MOVC语句，访问RAM块顺序使用片外操作的MOVX语句，访问内存片段使用MOV语句。8051单片机有4个8并行的I / O端口，分别为P0，P1，P2和P3。每个端口是8位精确的双向口，共占了32针。每一个I / O线可作为独立的入口和出口。每个端口包括一个锁存器（即特殊功能寄存器），一个出口驱动器和引进缓冲器。使数据能够锁存输出，数据可以及时缓冲，其余四个具有相同的功能。接外部存储扩大它们的内存时，这四个口就可作为双向口常用的I / O口，这是，P2口看到高8位地址，P0口是一个公共两用口，传送输出低8的地址和数据。P3口的输出级别小于P1，可以在里面绘制负载电阻，每一个都能驱动4个LS型TTL负载输出。作为输入口时，所有TTL或NMOS电路都可以驱动一个正常的方式8051 - P3口作为单片机的P1口。可以利用改变电阻的输出大小，直接地充当震荡开路，不需要添加外部电阻。其中每个口都是标准的双向口。当在当做输入口时，必须把相应的端口置1来锁闭输出。比如8051单片机，所有端口提供的输出电流只能几毫安，用作输出口时接一个普通的晶体管，要稳定使用，还要接一定电阻。其主要功能是把初始地址设为0000H，使单片机从0000H的地址开始运行程序。除了正常进入系统的初始化，由于操作失误或操作过程错误，也要能够解决错误，重新运行。在8051中RST引脚是一个输入复位键，复位键高电平信号有效，要保证24倍以上的时钟周期（即2个机器周期）。如果收到高频的6v输入信号，单片机就会复位。初始化时，需要两部分外部电路。外部电路采用施密特触发方式触发了复位键（RST），形成了复位信号输出电路，并把信号传送到每个引脚，按顺序到了复位引脚，就会迅速响应信号指令。复位功能的可靠性，适合6v电压的电容震荡电路，复位信号的周期可以大于两个机器周期。虽然复位电路的结构很简单，但它的功能是非常重要的。一个单片机系统能否正常运行，应先检查它有没有正确的复位电路。检查和检测其发出信号，用示波器显示时，结合复位电路很重要，观察波形时，输出口（瞬时）的波动范围是很大的，也可以通过复位电路对实验进行有必要的改变。2.外文原文：Structure and function of the MCS-51 series Structure and function of the MCS-51 series one-chip computer MCS-51 is a name of a piece of one-chip computer series which Intel Company produces. This company introduced 8 top-grade one-chip computers of MCS-51 series in 1980 after introducing 8 one-chip computers of MCS-48 series in 1976. It belong to a lot of kinds this line of one-chip computer the chips have,such as 8051, 8031, 8751, 80C51BH, 80C31BH,etc., their basic composition, basic performance and instruction system are all the same. 8051 daily representatives- 51 serial one-chip computers . An one-chip computer system is made up of several following parts: ( 1) One microprocessor of 8 (CPU). ( 2) At slice data memory RAM (128B/256B),it use not depositting not can reading /data that write, such as result not middle of operation, final result and data wanted to show, etc. ( 3) Procedure memory ROM/EPROM (4KB/8KB ), is used to preserve the procedure , some initial data and form in slice. But does not take ROM/EPROM within some one-chip computers, such as 8031 , 8032, 80C ,etc. ( 4) Four 8 run side by side I/O interface P0 four P3, each mouth can use as introduction , may use as exporting too. ( 5) Two timer / counter, each timer / counter may set up and count in the way, used to count to the external incident, can set up into a timing way too, and can according to count or result of timing realize the control of the computer. ( 6) Five cut off cutting off the control system of the source . ( 7) One all duplexing serial I/O mouth of UART (universal asynchronous receiver/transmitter (UART) ), is it realize one-chip computer or one-chip computer and serial communication of computer to use for. ( 8) Stretch oscillator and clock produce circuit, quartz crystal finely tune electric capacity need outer. Allow oscillation frequency as 12 megahertas now at most. Every the above-mentioned part was joined through the inside data bus .Among them, CPU is a core of the one-chip computer, it is the control of the computer and command centre, made up of such parts as arithmetic unit and controller , etc. The arithmetic unit can carry on 8 persons of arithmetic operation and unit ALU of logic operation while including one, the 1 storing device temporarilies of 8, storing device 2 temporarily, 8s accumulation device ACC, register B and procedure state register PSW, etc. Person who accumulate ACC count by 2 input ends entered of checking etc. temporarily as one operation often, come from person who store 1 operation is it is it make operation to go on to count temporarily , operation result and loopback ACC with another one. In addition, ACC is often regarded as the transfer station of data transmission on 8051 inside . The same as general microprocessor, it is the busiest register. Help remembering that agreeing with A expresses in the order. The controller includes the procedure counter , the order is depositted, the order decipher, the oscillator and timing circuit, etc. The procedure counter is made up of counter of 8 for two, amounts to 16. It is a byte address counter of the procedure in fact, the content is the next IA that will carried out in PC. The content which changes it can change the direction that the procedure carries out . Shake the circuit in 8051 one-chip computers, only need outer quartz crystal and frequency to finely tune the electric capacity, its frequency range is its 12MHZ of 1.2MHZ. This pulse signal, as 8051 basic beats of working, namely the minimum unit of time. 8051 is the same as other computers, the work in harmony under the control of the basic beat, just like an orchestra according to the beat play that is commanded. There are ROM (procedure memory , can only read ) and RAM in 8051 slices (data memory, can is it can write ) two to read, they have each independent memory address space, dispose way to be the same with general memory of computer. Procedure 8051 memory and 8751 slice procedure memory capacity 4KB, address begin from 0000H, used for preserving the procedure and form constant. Data 8051- 8751 8031 of memory data memory 128B, address false 00FH, use for middle result to deposit operation, the data are stored temporarily and the data are buffered etc. In RAM of this 128B, there is unit of 32 byteses that can be appointed as the job register, this and general microprocessor is different, 8051 slice RAM and job register rank one formation the same to arrange the location. It is not very the same that the memory of MCS-51 series one-chip computer and general computer disposes the way in addition. General computer for first address space, ROM and RAM can arrange in different space within the range of this address at will, namely the addresses of ROM and RAM, with distributing different address space in a formation. While visiting the memory, corresponding and only an address Memory unit, can ROM, it can be RAM too, and by visiting the order similarly. This kind of memory structure is called the structure of Princeton. 8051 memories are divided into procedure memory space and data memory space on the physics structure, there are four memory spaces in all: The procedure stores in one and data memory space outside data memory and one in procedure memory space and one outside one, the structure forms of this kind of procedure device and data memory separated form data memory, called Harvard structure. But use the angle from users, 8051 memory address space is divided into three kinds: (1) In the slice, arrange blocks of FFFFH , 0000H of location , in unison outside the slice (use 16 addresses). (2) The data memory address space outside one of 64KB, the address is arranged from 0000H 64KB FFFFH (with 16 addresses ) too to the location. (3) Data memory address space of 256B (use 8 addresses). Three above-mentioned memory space addresses overlap, for distinguishing and designing the order symbol of different data transmission in the instruction system of 8051: CPU visit slice, ROM order spend MOVC , visit block RAM order uses MOVX outside the slice, RAM order uses MOV to visit in slice. 8051 one-chip computer have four 8 walk abreast I/O port, call P0, P1, P2 and P3. Each port is 8 accurate two-way mouths, accounts for 32 pins altogether. Every one I/O line can be used as introduction and exported independently. Each port includes a latch (namely special function register ), one exports the driver and a introduction buffer . Make data can latch when outputting, data can buffer when making introduction , but four function of passway these self-same. Expand among the system of memory outside having slice, four port these may serve as accurate two-way mouth of I/O in common use. Expand among the system of memory outside having slice, P2 mouth see high 8 address off; P0 mouth is a two-way bus, send the introduction of 8 low addresses and data / export in timesharing Output grade , P3 of mouth , P1 of P1 , connect with inside have load resistance of drawing , every one of they can drive 4 Model LS TTL load to output. As while inputting the mouth, any TTL or NMOS circuit can drive P1 of 8051 one-chip computers as P3 mouth in a normal way . Because draw resistance on output grade of them have, can open a way collector too or drain-source resistance is it urge to open a way, do not need to have the resistance of drawing outerly . Mouths are all accurate two-way mouths too. When the conduct is input, must write the corresponding port latch with 1 first . As to 80C51 one-chip computer, port can only offer milliampere of output electric currents, is it output mouth go when urging one ordinary basing of transistor to regard as, should contact a resistance among the port and transistor base , in order to the electricity while restraining the high level from exporting P1P3 Being restored to the throne is the operation of initializing of an one-chip computer. Its main function is to turn PC into 0000H initially , make the one-chip computer begin to hold the conduct procedure from unit 0000H. Except that the ones that enter the system are initialized normally,as because procedure operate it make mistakes or operate there arent mistake, in order to extricate oneself from a predicament , need to be pressed and restored to the throne the key restarting too. It is an input end which is restored to the throne the signal in 8051 China RST pin. Restore to the throne signal high level effective , should sustain 24 shake cycle (namely 2 machine cycles ) the above its effective times. If 6 of frequency of utilization brilliant to shake, restore to the throne signal duration should exceed 4 delicate to finish r