1、Structure and function of the MCS-51 seriesThe 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
2、 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 .51系列单片机是由英特尔公司生产的的单片机产品。
3、该家公司在 1976年发行了 8位 MCS-48系列。然后又在在 1980年推出了高 8位的 MCS-51系列单片机。它属于这一类型很多行一个芯片的电脑芯片都如8051、8031、8751、80c51bh,80c31bh 等,其基本组成、性能和基本教学制度,都是一样的. 8051 通常是 51系列的代表。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
4、 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-c
5、hip 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
6、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 compute
7、r 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 d
8、ata 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, th
9、e 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
10、 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 wi
11、th 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 conten
12、t 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.
13、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
14、) 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
15、 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, th
16、is 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
17、 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 o
18、rder 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
19、 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 ,
20、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 spa
21、ce 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
22、 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 introductio
23、n 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
24、 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 8051 单片机有 4 组并排的 8 位 I/O 口，叫做 P0, P1, P2 和 P3.每一个端口都是 8 位准双向口，共占 32 根引脚。每个 I/O 线路都可以被用做输入和输出口。每个端口都包括一个锁存器（即专用存储器） ，一个输出驱动器和输入缓冲器。是数据在输出时能被锁存，当
25、执行输入时数据能缓存，但是他们四个通道的功能相同。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
26、. 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 l
27、atch 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 restrai
28、ning 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 sy
29、stem 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 C
30、hina 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 restoring to the thr
31、one and operating. Produce the logic picture of circuit which is restored to the throne the signal:Restore to the throne the circuit and include two parts outside in the chip entirely. Outside that circuit produce to restore to the throne signal (RST ) hand over to Schmitts trigger, restore to the t
32、hrone circuit sample to output , Schmitt of trigger constantly in each S5P2 , machine of cycle in having one more , then just got and restored to the throne and operated the necessary signal insidly. Restore to the throne resistance of circuit generally, electric capacity parameter suitable for 6 br
33、illiant to shake, can is it restore to the throne signal high level duration greater than 2 machine cycles to guarantee. Being restored to the throne in the circuit is simple, its function is very important. Pieces of one-chip computer system could normal running,should first check it can restore to
34、 the throne not succeeding. Checking and can pop ones head and monitor the pin with the oscillograph tentatively, push and is restored to the throne the key, the wave form that observes and has enough range is exported (instantaneous), can also through is it restore to the throne circuit group holdi
35、ng value carry on the experiment to change.At present,MCU to infiltrate all areas of our lives, which is almost difficult to find traces of the field without SCM. Missile navigation equipment, aircraft, all types of instrument control, computer network communications and data transmission, industria
36、l automation, real-time process control and data processing, extensive use of various smart IC card, civilian luxury car security system, video recorder, camera, fully automatic washing machine control, and program-controlled toys, electronic pet, etc., which are inseparable from the microcontroller
37、. Not to mention the area of robot control, intelligent instruments, medical equipment was. Therefore, the MCU learning, development and application of the large number of computer applications and intelligent control of the scientists, engineers. SCM is widely used in instruments and meters, househ
38、old appliances, medical equipment, aerospace, specialized equipment, intelligent management and process control fields, roughly divided into the following several areas:（1）In the application of Intelligent InstrumentsSCM has a small size, low power consumption, controlling function, expansion flexib
39、ility, the advantages of miniaturization and ease of use, widely used instrument, combining different types of sensors can be realized Zhuru voltage, power, frequency, humidity, temperature, flow, speed, thickness, angle, length, hardness, elemental, physical pressure measurement. SCM makes use of d
40、igital instruments, intelligence, miniaturization, and functionality than electronic or digital circuits more powerful. Such as precision measuring equipment (power meter, oscilloscope, various analytical instrument).（2）In the industrial control applicationWith the MCU can constitute a variety of co
41、ntrol systems, data acquisition system. Such as factory assembly line of intelligent control,all kinds of alarm systems,and computer networks constitute a secondary control system.（3）In the Appliance of Household appliances It can be said that the appliances are basically using SCM, praise from the
42、electric rice, washing machines, refrigerators, air conditioners, color TV, and other audio video equipment, to the electronic weighing equipment, varied, and omnipresent.（4）In the field of computer networks and communications applications MCU general with modern communication interface, can be easy
43、 with the computer data communication, networking and communications in computer applications between devices had excellent material conditions, are basically all communication equipment to achieve a controlled by MCU from mobile phone, telephone, mini-program-controlled switchboards, building autom
44、ated communications call system, train radio communication, to the daily work can be seen everywhere in the mobile phones, trunked mobile radio, walkie-talkies, etc.（5）Microcomputer in the field of medical device applicationsMCU in the use of medical devices is also quite extensive, such as medical
45、respirator, the various analyzers, monitors, ultrasound diagnostic equipment and hospital beds, etc. call system. （6）In a variety of major appliances in the modular applications Designed to achieve some special single specific function to be modular in a variety of circuit applications, without requ
46、iring the use of personnel to understand its internal structure. If music integrated single chip, seemingly simple function, miniature electronic chip in the net (the principle is different from the tape machine), you need a computer similar to the principle of the complex. Such as: music signal to
47、digital form stored in memory (like ROM), read by the microcontroller, analog music into electrical signals (similar to the sound card). In large circuits, modular applications that greatly reduce the volume, simplifies the circuit and reduce the damage, error rate, but also easy to replace. （7）Micr
48、ocontroller in the application field of automotive equipment SCM in automotive electronics is widely used, such as a vehicle engine controller, CAN bus-based Intelligent Electronic Control Engine, GPS navigation system, abs anti-lock braking system, brake system, etc. In addition, the MCU in busines
49、s, finance, research, education, national defense, aerospace and other fields has a very wide range of applications.译文51 系列单片机的功能和结构结构和功能的监控监-51 系列之一-计算机芯片监控监-51 名是一幅一个电脑晶片,英特尔公司生产系列. 这家公司推出 8级一个计算机芯片监控监-51 系列之后,于 1980年 8引入一个计算机芯片监控监,于 1976年 48系列.。它属于这一类型很多行一个芯片的电脑芯片都如 8051、8031、8751、80c51bh,80c31bh 等,其基本组成、性能和基本教学制度,都是一样的. 8051每日代表-51 系列之一-电脑晶片 有一个芯片的计算机系统是由以下几个方面: (1)18微处理器(CPU). (2)在切片数据存储羊(128B/256B),使用可以不读书不数据写如因经营不中,最后结果要和数据显示等. (3)存储器存储程序/可擦写可编程只读存储器(4KB/8KB),用于保存程序和数据,初步形成片. 但并不存储器/可擦写可编程只读存储器在一些人的电脑芯片,如 8031、8032、80c 等. （4)经营的 84并肩一/四 OP0P3接口,每口可以用作介绍
