外文参考文献模板最新 李晓旭 2.docx

1、外文参考文献模板最新 李晓旭 2本科生毕业设计（论文）专业外文翻译原 文：PC and single chip microcomputer serial communication design 译 文：关于PC机与单片机串行通信设计的实现指导教师 ： 宋东亚 职称： 讲师 学生姓名 ： 李晓旭 学号： 1002120107 专 业 ： 电气工程及其自动化 院（系） ： 机电工程学院 2014年3月20日PC and single chip microcomputer serial communication designPC is the abbreviation of the Person

2、al Computer, which can run independently, perform specific functions of the Personal Computer. Personal computer does not need to share other computer resources such as processing, disks and printer can work independently.1. 1. PC development brief historyAccording to the logic element process chang

3、e, can be divided into four stages: first generation: 1946-1958 is the vacuum tube computer. Its characteristic is that the big volume, power consumption, more slowly, but laid the foundation of computer technology. second generation: 1958-1964 is the transistor computer. Its characteristic is that

4、the volume reduction, reduce power consumption, speed, cost reduction; third generation: 1964-1971 is the integrated circuit computer, than on the characteristics of the second generation of the third generation has a larger increase; fourth generation: mass of very large scale integrated circuit co

5、mputer since 1971, it from large to tiny development, cost performance is greatly improved; The fifth generation computer will develop to is.1.2. The PC hardware profileHardware is running software platform, software control hardware work to complete the scheduled tasks. First of all, let us underst

6、and the computer hardware.1.2.1. Central processing unit (CPU)The CPU is the abbreviation of central processing unit (CPU), it is the core computer components. CPU chip mainly contain arithmetic unit and controller. unitArithmetic unit is used for data arithmetic operation (addition, subtraction, mu

7、ltiplication, division, etc.) and logic operations (comparison, shift, Boolean calculation, etc.) of the device. Data from memory in the unit operation, operation result and sent to memory, these operations are carried out under the control of the controller. controllerController is the command cent

8、er of the computer, is used to control, accused the entire computer system automatically, continuously running and coordinated work between the parts.Single chip microcomputer hereinafter referred to as single chip microcomputer, it is the central processing unit (CPU), memory (RAM and ROM), timer/c

9、ounter, and all sorts of interface circuits are integrated into a integrated circuit chip microcomputer. With the development of computer technology, especially the single chip microcomputer technology, people have increasingly come to some industrial control system by single chip microcomputer test

10、ing and control parameters such as temperature and humidity. PC machine has powerful monitoring and management functions, while MCU have the characteristics of fast and flexible control, through the PC RS 232 serial interface to communicate with external devices, is a kind of communication that is c

11、ommonly used in many measurement and control system solutions. So how to realize the communication between PC and single chip microcomputer has very important practical significance. For some remote control or risk is higher, the application of the data acquisition and control, this paper mainly int

12、roduces a way of using duplex implementation of serial communication between PC and single chip microcomputer.Serial communication refers to the peripherals and computer use a data line between a a transmission of data, each data occupy a fixed length of time. Serial refers to the way of information

13、 transmission between peripherals and interface circuit, between CPU and interface is still working in parallel way. Serial data during transmission, due to the interference may cause error information. How to find errors in the transmission, error detection; After found errors, how to eliminate the

14、 error, error correction.(1) serial data transmission mode1) double office way communication both sides can simultaneously send and receive operation.2) only 1 half duplex mode transferring data signals, requiring communications sent and received by the electronic switch on both sides. Because there

15、 is only one channel, so the data cant transfer in both directions at the same time.3) simplex mode allows only transmit data according to a fixed direction.(2) serial communication can be divided into two types: synchronous communication and asynchronous communication.Asynchronous communication: a

16、character in a character transfer, each character a a transmission, transmission of a character, begins with a start bit, and then transfer the character itself, ladies and gentlemen, then transfer check, finally ends with a stop bit the transmission of the characters. A transfer of the start bit, c

17、haracters, ladies and gentlemen, parity, stop bits, constitute a complete set of information, known as the Frame (Frame). Between the frame and the frame can have any spare time. After the start bit is the least significant data. (1) a start bit is located in the character frame at the beginning, on

18、ly one, for low level logic 0, is used to notify the receiving device, the sender to start sending data. Character on a line without transmission should be kept as 1. Receiving end constantly check the status of a line, such as continuous for later, 1 to a 0, know from a new character, should be rea

19、dy to receive immediately.(2) data: data bits (D0 - D7) j just behind the starting for, usually for 5 to 8, on the basis of data bits were transmitted from low to high order.(3) parity check bits, parity check bits only take up one, and immediately behind the data bits used to represent the serial c

20、ommunication using odd parity or even check, also can use this one (I/O) to determine the nature of this character represents more information in a frame (address/data, etc.).(4) stop bit: located in the character frame in the end, the characterization of the end of the characters, it must be a high

21、 level (logic 1). Stop bits can be 1, 1.5 a, 2 a. On the receiving end after receiving the stop bit, know a character has been transferred, and at the same time to prepare for receiving the next character (as long as to receive a 0 is the new characters of the start bit). If stop, since is not follo

22、wed by passing the next character, keep on a line as 1.Synchronous communication: synchronous transmission bit group is much larger. It is not independently send each character, each character has its own start and stop bits, but put them together to send together. We call these combined data frames

23、, or frames for short.This design topic research between systems, data transmission and control system and peripherals. Serial port in system and ACTS as a connection between peripheral tasks and in serial communications with RS485 and RS232 serial interface technology most widely used, this topic m

24、ainly studies design of RS485 serial port, and in order to meet the RS485 communication standard MAXIM company has designed a model named MAX488 for this chip, the chip connotation is a drive and a receiver, with low power consumption at the same time, single + 5 v power supply, the drive has overlo

25、ad protection, without external components, etc.AT89C2051 MCU when executing commands to failure, can through the chip IMP813 microcontroller reset. It can also be awaken single-chip computer from sleep mode or idle mode. In the present AT89 series single-chip microcomputer serial port communication

26、 technology in the current popular solution is to adopt RS485 interface. It takes one and two bus interface, USES a half duplex communication bus difference level of data transmission. Microcomputer to realize RS485 protocol communication generally summarized two methods can be used: the first USES

27、the communication card, inserted on computer motherboard expansion slot; The second USES RS232 and RS485 conversion interface device.System USES AT89C51 as a machine and PC as upper machine, both through the RS - 232 serial port to send and receive data. RS - 232 signal level and single chip microco

28、mputer serial signal level, must be between the two level transformation, system used in the integration level conversion chip MAX232 implementing RS - 232 / TTL level transformation.This design using the single chip microcomputer principle and microcomputer interface technology and so on knowledge

29、of single chip microcomputer and PC serial communication design. There are involved during description, serial communication system of serial communication principle, the electric standard of RS - 232 interface, level conversion method and the single chip microcomputer minimum system design related

30、issues.This system consists of hardware and softwareThis system consists of two parts of hardware and software coordination is complete, the hardware part mainly complete information display; Software mainly complete signal processing and control function, etc. System hardware design adopts modular

31、design, AT89C51 single-chip microcomputer as the core, the serial port communication circuit of control system. Software design using a query and receive interrupt way to complete data, and further processing.During implementation behind also adopted, for example, and the simulation debugging, namel

32、y using Protues platform, virtual serial port software to create virtual COM port, a pair of interlinked MSC0mm software based serial debugging software tools such as PC and single chip computer serial communication system simulation.Involving the baud rate in the title, baud rate the data transfer rate, said every second transmission of binary digits, it is the unit of g bit/SEC (b/s), commonly used BPS said. Baud rate is an important indicator of asynchronous communication, characterization data transmission speed, the higher the baud rate, the faster the spee