單片機(jī)控制系統(tǒng)中英文對(duì)照外文文獻(xiàn)翻譯

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1、單片機(jī)控制系統(tǒng)中英文對(duì)照外文翻譯文獻(xiàn) (含：英文原文及中文譯文) 英文原文 Microcomputer Systems Electronic systems are used for handing information in the most general sense; this information may be telephone conversation, instrument read or a company’s accounts, but in each case the same main type of operation are involved: the

2、 processing, storage and transmission of information. in conventional electronic design these operations are combined at the function level; for example a counter, whether electronic or mechanical, stores the current and increments it by one as required. A system such as an electronic clock which em

3、ploys counters has its storage and processing capabilities spread throughout the system because each counter is able to store and process numbers. Present day microprocessor based systems depart from this conventional approach by separating the three functions of processing, storage, and transmiss

4、ion into different section of the system. This partitioning into three main functions was devised by Von Neumann during the 1940s, and was not conceived especially for microcomputers. Almost every computer ever made has been designed with this structure, and despite the enormous range in their physi

5、cal forms, they have all been of essentially the same basic design. In a microprocessor based system the processing will be performed in the microprocessor itself. The storage will be by means of memory circuits and the communication of information into and out of the system will be by means of sp

6、ecial input/output(I/O) circuits. It would be impossible to identify a particular piece of hardware which performed the counting in a microprocessor based clock because the time would be stored in the memory and incremented at regular intervals but the microprocessor. However, the software which def

7、ined the system’s behavior would contain sections that performed as counters. The apparently rather abstract approach to the architecture of the microprocessor and its associated circuits allows it to be very flexible in use, since the system is defined almost entirely software. The design process i

8、s largely one of software engineering, and the similar problems of construction and maintenance which occur in conventional engineering are encountered when producing software. The figure1.1 illustrates how these three sections within a microcomputer are connected in terms of the communication of

9、information within the machine. The system is controlled by the microprocessor which supervises the transfer of information between itself and the memory and input/output sections. The external connections relate to the rest (that is, the non-computer part) of the engineering system. Although only

10、 one storage section has been shown in the diagram, in practice two distinct types of memory RAM and ROM are used. In each case, the word ‘memory’ is rather inappropriate since a computers memory is more like a filing cabinet in concept; information is stored in a set of numbered ‘boxes’ and it is r

11、eferenced by the serial number of the ‘box’ in question. Microcomputers use RAM (Random Access Memory) into which data can be written and from which data can be read again when needed. This data can be read back from the memory in any sequence desired, and not necessarily the same order in which it

12、 was written, hence the expression ‘random’ access memory. Another type of ROM (Read Only Memory) is used to hold fixed patterns of information which cannot be affected by the microprocessor; these patterns are not lost when power is removed and are normally used to hold the program which defines th

13、e behavior of a microprocessor based system. ROMs can be read like RAMs, but unlike RAMs they cannot be used to store variable information. Some ROMs have their data patterns put in during manufacture, while others are programmable by the user by means of special equipment and are called programmabl

14、e ROMs. The widely used programmable ROMs are erasable by means of special ultraviolet lamps and are referred to as EPROMs, short for Erasable Programmable Read Only Memories. Other new types of device can be erased electrically without the need for ultraviolet light, which are called Electrically E

15、rasable Programmable Read Only Memories, EEPROMs. The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling speci

16、al hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried o

17、ut without directly involving the main microprocessor. The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling sp

18、ecial hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carrie

19、d out without directly involving the main microprocessor. The microprocessor , memory and input/output circuit may all be contained on the same integrated circuit provided that the application does not require too much program or data storage . This is usually the case in low-cost application such

20、 as the controllers used in microwave ovens and automatic washing machines . The use of single package allows considerable cost savings to e made when articles are manufactured in large quantities . As technology develops , more and more powerful processors and larger and larger amounts of memory ar

21、e being incorporated into single chip microcomputers with resulting saving in assembly costs in the final products . For the foreseeable future , however , it will continue to be necessary to interconnect a number of integrated circuits to make a microcomputer whenever larger amounts of storage or i

22、nput/output are required. Another major engineering application of microcomputers is in process control. Here the presence of the microcomputer is usually more apparent to the user because provision is normally made for programming the microcomputer for the particular application. In process contr

23、ol applications the benefits lf fitting the entire system on to single chip are usually outweighed by the high design cost involved, because this sort lf equipment is produced in smaller quantities. Moreover, process controllers are usually more complicated so that it is more difficult to make them

24、as single integrated circuits. Two approaches are possible; the controller can be implemented as a general-purpose microcomputer rather like a more robust version lf a hobby computer, or as a ‘packaged’ system, signed for replacing controllers based on older technologies such as electromagnetic rela

25、ys. In the former case the system would probably be programmed in conventional programming languages such as the ones to9 be introduced later, while in the other case a special-purpose language might be used, for example one which allowed the function of the controller to be described in terms of re

26、lay interconnections, In either case programs can be stored in RAM, which allows them to be altered to suit changes in application, but this makes the overall system vulnerable to loss lf power unless batteries are used to ensure continuity of supply. Alternatively programs can be stored in ROM, in

27、which case they virtually become part of the electronic ‘hardware’ and are often referred to as firmware. More sophisticated process controllers require minicomputers for their implementation, although the use lf large scale integrated circuits ‘the distinction between mini and microcomputers, Produ

28、cts and process controllers of various kinds represent the majority of present-day microcomputer applications, the exact figures depending on one’s interpretation of the word ‘product’. Virtually all engineering and scientific uses of microcomputers can be assigned to one or other of these categorie

29、s. But in the system we most study Pressure and Pressure Transmitters. Pressure arises when a force is applied over an area. Provided the force is one Newton and uniformly over the area of one square meters, the pressure has been designated one Pascal. Pressure is a universal processing condition. I

30、t is also a condition of life on the planet: we live at the bottom of an atmospheric ocean that extends upward for many miles. This mass of air has weight, and this weight pressing downward causes atmospheric pressure. Water, a fundamental necessity of life, is supplied to most of us under pressure.

31、 In the typical process plant, pressure influences boiling point temperatures, condensing point temperatures, process efficiency, costs, and other important factors. The measurement and control of pressure or lack of it-vacuum-in the typical process plant is critical. The working instruments in th

32、e plant usually include simple pressure gauges, precision recorders and indicators, and pneumatic and electronic pressure transmitters. A pressure transmitter makes a pressure measurement and generates either a pneumatic or electrical signal output that is proportional to the pressure being sensed.

33、 In the process plant, it is impractical to locate the control instruments out in the place near the process. It is also true that most measurements are not easily transmitted from some remote location. Pressure measurement is an exception, but if a high pressure of some dangerous chemical is to be

34、 indicated or recorded several hundred feet from the point of measurement, a hazard may be from the pressure or from the chemical carried. To eliminate this problem, a signal transmission system was developed. This system is usually either pneumatic or electrical. And control instruments in one lo

35、cation. This makes it practical for a minimum number of operators to run the plant efficiently. When a pneumatic transmission system is employed, the measurement signal is converted into pneumatic signal by the transmitter scaled from 0 to 100 percent of the measurement value. This transmitter is

36、mounted close to the point of measurement in the process. The transmitter output-air pressure for a pneumatic transmitter-is piped to the recording or control instrument. The standard output range for a pneumatic transmitter is 20 to 100kPa, which is almost universally used. When an electronic pre

37、ssure transmitter is used, the pressure is converted to electrical signal that may be current or voltage. Its standard range is from 4 to 20mA DC for current signal or from 1 to 5V DC for voltage signal. Nowadays, another type of electrical signal, which is becoming common, is the digital or discret

38、e signal. The use of instruments and control systems based on computer or forcing increased use of this type of signal. Sometimes it is important for analysis to obtain the parameters that describe the sensor/transmitter behavior. The gain is fairly simple to obtain once the span is known. Conside

39、r an electronic pressure transmitter with a range of 0~600kPa.The gain is defined as the change in output divided by the change in input. In this case, the output is electrical signal (4~20mA DC) and the input is process pressure (0~600kPa). Thus the gain. Beside we must measure Temperature Temperat

40、ure measurement is important in industrial control, as direct indications of system or product state and as indirect indications of such factors as reaction rates, energy flow, turbine efficiency, and lubricant quality. Present temperature scales have been in use for about 200 years, the earliest in

41、struments were based on the thermal expansion of gases and liquids. Such filled systems are still employed, although many other types of instruments are available. Representative temperature sensors include: filled thermal systems, liquid-in-glass thermometers, thermocouples, resistance temperature

42、detectors, thermostats, bimetallic devices, optical and radiation pyrometers and temperature-sensitive paints. Advantages of electrical systems include high accuracy and sensitivity, practicality of switching or scanning several measurements points, larger distances possible between measuring elem

43、ents and controllers, replacement of components(rather than complete system), fast response, and ability to measure higher temperature. Among the electrical temperature sensors, thermocouples and resistance temperature detectors are most widely used. Description The AT89C51 is a low-power, high-pe

44、rformance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows t

45、he program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control a

46、pplications. Function characteristic The AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, t

47、he AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down Mode saves the RAM conte

48、nts but freezes the oscillator disabling all other chip functions until the next hardware reset. Pin Description VCC:Supply voltage. GND:Ground. Port 0: Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port

49、 0 pins, the pins can be used as highimpedance inputs.Port 0 may also be configured to be the multiplexed loworder address/data bus during accesses to external program and data memory. In this mode P0 has internal pullups.Port 0 also receives the code bytes during Flash programming,and outputs the c

50、ode bytes during programverification. External pullups are required during programverification. Port 1 Port 1 is an 8-bit bi-directional I/O port with internal pullups.The Port 1 output buffers can sink/source four TTL inputs.When 1s are written to Port 1 pins they are pulled high by the internal

51、 pullups and can be used as inputs. As inputs,Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 1 also receives the low-order address bytes during Flash programming and verification. Port 2 Port 2 is an 8-bit bi-directional I/O port w

52、ith internal pullups.The Port 2 output buffers can sink/source four TTL inputs.When 1s are written to Port 2 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 2 pins that are externally being pulled low will source current, because of the internal pullups.Po

53、rt 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses. In this application, it uses strong internal pullupswhen emitting 1s. During accesses to external data memory that use 8-bit addresses, Port 2 emi

54、ts the contents of the P2 Special Function Register.Port 2 also receives the high-order address bits and some control signals during Flash programming and verification. Port 3 Port 3 is an 8-bit bi-directional I/O port with internal pullups.The Port 3 output buffers can sink/source four TTL inpu

55、ts.When 1s are written to Port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functions of various special features of the AT89C51 as lis

56、ted below: Port 3 also receives some control signals for Flash programming and verification. RST Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. ALE/PROG Address Latch Enable output pulse for latching the low byte of the address during

57、 accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during

58、 each access to external Data Memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller i

59、s in external execution mode. PSEN Program Store Enable is the read strobe to external program memory.When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memor

60、y. EA/VPP External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset.EA should be strapped to VCC for i

61、nternal program executions.This pin also receives the 12-volt programming enable voltage(VPP) during Flash programming, for parts that require12-volt VPP. XTAL1 Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2 Output from the inverting osci

62、llator amplifier. Oscillator Characteristics XTAL1 and XTAL2 are the input and output, respectively,of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1.Either a quartz crystal or ceramic resonator may be used. To drive the device from an extern

63、al clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2.There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low

64、 time specifications must be observed. 中文譯文 單片機(jī)控制系統(tǒng) 廣義地說(shuō)，微型計(jì)算機(jī)控制系統(tǒng)(單片機(jī)控制系統(tǒng))是用于處理信息的，這種被用于處理的信息可以是電話交談，也可以是儀器的讀數(shù)或者是一個(gè)企業(yè)的帳戶(hù)，但是各種情況下都涉及到相同的主要操作:信息的處理、信息的存儲(chǔ)和信息的傳遞。在常規(guī)的電子設(shè)計(jì)中，這些操作都是以功能平臺(tái)方式組合起來(lái)的，例如計(jì)數(shù)器，無(wú)論是電子計(jì)數(shù)器還是機(jī)械計(jì)數(shù)器，都要存儲(chǔ)當(dāng)前的數(shù)值，并且按要求將該數(shù)值增加 1。一個(gè)系統(tǒng)例如采用計(jì)數(shù)器的電子鐘之類(lèi)的任一系統(tǒng)要使其存儲(chǔ)和處理能力遍布整個(gè)系統(tǒng)，因?yàn)槊總€(gè)計(jì)數(shù)器都能存儲(chǔ)和處理一些數(shù)字。

65、 現(xiàn)如今，以微處理器為基礎(chǔ)的系統(tǒng)從常規(guī)的處理方法中分離了出來(lái)，它將信息的處理，信息的存儲(chǔ)和信息的傳輸三個(gè)功能分離形成不同的系統(tǒng)單元。這種主要將系統(tǒng)分成三個(gè)主要單元的分離方法是馮-諾依曼在 20 世紀(jì) 40 年代所設(shè)想出來(lái)的，并且是針對(duì)微計(jì)算機(jī)的設(shè)想。從此以后基本上所有制成的計(jì)算機(jī)都是用這種結(jié)構(gòu)設(shè)計(jì)的，盡管他們包含著寬廣的物理形式與物理結(jié)構(gòu)，但從根本上來(lái)說(shuō)他們均是具有相同基本設(shè) 計(jì)的計(jì)算機(jī)。 在以微處理器為基礎(chǔ)的系統(tǒng)中，處理是由以微處理器為基礎(chǔ)的系統(tǒng)自身完成的。存儲(chǔ)是利用存儲(chǔ)器電路，而從系統(tǒng)中輸入和輸出的信息傳輸則是利用特定的輸入/輸出(I/O)電路。要在一個(gè)以微處理器為基礎(chǔ)的時(shí)鐘中找出執(zhí)

66、行具有計(jì)數(shù)功能的一個(gè)特殊的硬件組成部分是不可能的，因?yàn)闀r(shí)間存儲(chǔ)在存儲(chǔ)器中，而在固定的時(shí)間間隔下由微處理器控制增值。但是，規(guī)定系統(tǒng)運(yùn)轉(zhuǎn)過(guò)程的軟件卻規(guī)定了包含實(shí)現(xiàn)計(jì)數(shù)器計(jì)數(shù)功能的單元部分。由于系統(tǒng)幾乎完全由軟件所定義，所以對(duì)微處理器結(jié)構(gòu)和其輔助電路這種看起來(lái)非常抽象的處理方法使其在應(yīng)用時(shí)非常靈活。這種設(shè)計(jì)過(guò)程主要是軟件工程，而且在生產(chǎn)軟件時(shí)，就會(huì)遇到產(chǎn)生于常規(guī)工程中相似的構(gòu)造和維護(hù)問(wèn)題。 圖1.1顯示出了微型計(jì)算機(jī)中這三個(gè)單元在一個(gè)微處理器控制系統(tǒng)中是如何按照機(jī)器中的信息通信方式而聯(lián)接起來(lái)的。該系統(tǒng)由微處理器控制，微處理器能夠?qū)ζ渥陨淼拇鎯?chǔ)器和輸入/輸出單元的信息傳輸進(jìn)行管理。外部的連接部分與工程系統(tǒng)中的其余部分(即非計(jì)算機(jī)部分)有關(guān)。 盡管圖中顯示的只有一個(gè)存儲(chǔ)單元，但是在實(shí)際中卻有 RAM 和 ROM 兩種不同的存儲(chǔ)器被使用。在每一種情況下，由于概念上的計(jì)算機(jī)存儲(chǔ)器更像一個(gè)公文柜，上述的“存儲(chǔ)器”一詞是非常不恰當(dāng)?shù)?信息被存放在一系列已數(shù)字標(biāo)記過(guò)的的“箱子”中，而且可以按照問(wèn)題由“箱子”的序列號(hào)進(jìn)行相關(guān)信息的參考定位。 微計(jì)算機(jī)控制系統(tǒng)經(jīng)常使用 RAM(隨機(jī)存取存儲(chǔ)器)，在