單片機(jī)設(shè)計(jì)外文翻譯3

1、<p><b>　　外文：</b></p><p><b>　　MCU</b></p><p>　　A microcontroller (or MCU) is a computer-on-a-chip. It is a type of microprocessor emphasizing self-sufficiency and cos

2、t-effectiveness, in contrast to a general-purpose microprocessor (the kind used in a PC). </p><p>　　The majority of computer systems in use today are embedded in other machinery, such as telephones, clocks,

3、appliances, vehicles, and infrastructure. An embedded system usually has minimal requirements for memory and program length and may require simple but unusual input/output systems. For example, most embedded systems lack

4、 keyboards, screens, disks, printers, or other recognizable I/O devices of a personal computer. They may control electric motors, relays or voltages, and read switches, vari</p><p>　　In contrast to general-p

5、urpose CPUs, microcontrollers do not have an address bus or a data bus, because they integrate all the RAM and non-volatile memory on the same chip as the CPU. Because they need fewer pins, the chip can be placed in a mu

6、ch smaller, cheaper package. </p><p>　　Integrating the memory and other peripherals on a single chip and testing them as a unit increases the cost of that chip, but often results in decreased net cost of the

7、 embedded system as a whole. (Even if the cost of a CPU that has integrated peripherals is slightly more than the cost of a CPU + external peripherals, having fewer chips typically allows a smaller and cheaper circuit bo

8、ard, and reduces the labor required to assemble and test the circuit board). This trend leads to design. </p><p>　　A microcontroller is a single integrated circuit, commonly with the following features: <

9、/p><p>　　central processing unit - ranging from small and simple 4-bit processors to sophisticated 32- or 64-bit processors input/output interfaces such as serial ports (UARTs) </p><p>　　other seri

10、al communications interfaces like I²C, Serial Peripheral Interface and Controller Area Network for system interconnect peripherals such as timers and watchdog RAM for data storage ROM, EPROM, EEPROM or Flash memor

11、y for program storage clock generator - often an oscillator for a quartz timing crystal, resonator or RC circuit many include analog-to-digital converters .</p><p>　　This integration drastically reduces the

12、 number of chips and the amount of wiring and PCB space that would be needed to produce equivalent systems using separate chips and have proved to be highly popular in embedded systems since their introduction in the 197

13、0s. </p><p>　　Some microcontrollers can afford to use a Harvard architecture: separate memory buses for instructions and data, allowing accesses to take place concurrently. </p><p>　　The decisio

14、n of which peripheral to integrate is often difficult. The Microcontroller vendors often trade operating frequencies and system design flexibility against time-to-market requirements from their customers and overall lowe

15、r system cost. Manufacturers have to balance the need to minimize the chip size against additional functionality. </p><p>　　Microcontroller architectures are available from many different vendors in so many

16、varieties that each instruction set architecture could rightly belong to a category of their own. Chief among these are the 8051, Z80 and ARM derivatives.</p><p>　　A microcontroller (also MCU or µC) is

17、a functional computer system-on-a-chip. It contains a processor core, memory, and programmable input/output peripherals.</p><p>　　Microcontrollers include an integrated CPU, memory (a small amount of RAM, pr

18、ogram memory, or both) and peripherals capable of input and output. </p><p>　　It emphasizes high integration, in contrast to a microprocessor which only contains a CPU (the kind used in a PC). In addition to

19、 the usual arithmetic and logic elements of a general purpose microprocessor, the microcontroller integrates additional elements such as read-write memory for data storage, read-only memory for program storage, Flash mem

20、ory for permanent data storage, peripherals, and input/output interfaces. At clock speeds of as little as 32KHz, microcontrollers often operate at very</p><p>　　Microcontrollers are used in automatically con

21、trolled products and devices, such as automobile engine control systems, remote controls, office machines, appliances, power tools, and toys. By reducing the size, cost, and power consumption compared to a design using a

22、 separate microprocessor, memory, and input/output devices, microcontrollers make it economical to electronically control many more processes.</p><p>　　The majority of computer systems in use today are embed

23、ded in other machinery, such as automobiles, telephones, appliances, and peripherals for computer systems. These are called embedded systems. While some embedded systems are very sophisticated, many have minimal requirem

24、ents for memory and program length, with no operating system, and low software complexity. Typical input and output devices include switches, relays, solenoids, LEDs, small or custom LCD displays, radio frequency devices

25、, and</p><p>　　It is mandatory that microcontrollers provide real time response to events in the embedded system they are controlling. When certain events occur, an interrupt system can signal the processor

26、to suspend processing the current instruction sequence and to begin an interrupt service routine (ISR). The ISR will perform any processing required based on the source of the interrupt before returning to the original i

27、nstruction sequence. Possible interrupt sources are device dependent, and often include </p><p>　　Microcontroller programs must fit in the available on-chip program memory, since it would be costly to provid

28、e a system with external, expandable, memory. Compilers and assembly language are used to turn high-level language programs into a compact machine code for storage in the microcontroller's memory. Depending on the de

29、vice, the program memory may be permanent, read-only memory that can only be programmed at the factory, or program memory may be field-alterable flash or erasable read-only me</p><p>　　Since embedded process

30、ors are usually used to control devices, they sometimes need to accept input from the device they are controlling. This is the purpose of the analog to digital converter. Since processors are built to interpret and proce

31、ss digital data, i.e. 1s and 0s, they won't be able to do anything with the analog signals that may be being sent to it by a device. So the analog to digital converter is used to convert the incoming data into a form

32、 that the processor can recognize. There i</p><p>　　In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers is the Programmabl

33、e Interval Timer, or PIT for short. A PIT just counts down from some value to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such a

34、s thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on, the he</p><p>　　Time Processing Unit or TPU for short. Is essentially just another timer

35、, but more sophisticated. In addition to counting down, the TPU can detect input events, generate output events, and other useful operations.</p><p>　　Dedicated Pulse Width Modulation (PWM) block makes it po

36、ssible for the CPU to control power converters, resistive loads, motors, etc., without using lots of CPU resources in tight timer loops.</p><p>　　Universal Asynchronous Receiver/Transmitter (UART) block make

37、s it possible to receive and transmit data over a serial line with very little load on the CPU.</p><p>　　For those wanting ethernet one can use an external chip like Crystal Semiconductor CS8900A, Realtek RT

38、L8019, or Microchip ENC 28J60. All of them allow easy interfacing with low pin count.</p><p><b>　　中文翻譯：</b></p><p><b>　　單片機(jī)</b></p><p>　　單片機(jī)即單片微型計(jì)算機(jī)，是把中央處理器、

39、存儲(chǔ)器、定時(shí)/計(jì)數(shù)器、輸入輸出接口都集成在一塊集成電路芯片上的微型計(jì)算機(jī)。與應(yīng)用在個(gè)人電腦中的通用型微處理器相比，它更強(qiáng)調(diào)自供應(yīng)（不用外接硬件）和節(jié)約成本。它的最大優(yōu)點(diǎn)是體積小，可放在儀表內(nèi)部，但存儲(chǔ)量小，輸入輸出接口簡單，功能較低。由于其發(fā)展非常迅速，舊的單片機(jī)的定義已不能滿足，所以在很多應(yīng)用場(chǎng)合被稱為范圍更廣的微控制器，但是目前在中國大陸仍多沿用“單片機(jī)”的稱呼。 </p><p>　　絕大多數(shù)現(xiàn)在的單片機(jī)都

40、是基于馮·諾伊曼結(jié)構(gòu)的，這種結(jié)構(gòu)清楚地定義了嵌入式系統(tǒng)所必需的四個(gè)基本部分：一個(gè)中央處理器核心，程序存儲(chǔ)器（只讀存儲(chǔ)器或者閃存）、數(shù)據(jù)存儲(chǔ)器（隨機(jī)存儲(chǔ)器），一個(gè)或者更多的定時(shí)/計(jì)時(shí)器，還有用來與外圍設(shè)備以及擴(kuò)展資源進(jìn)行通信的輸入/輸出端口——所有這些都被集成在單個(gè)集成電路芯片上。說單片機(jī)與通用型中央處理單元芯片不同是因?yàn)榍罢咭话愫苋菀着浜献钚⌒偷耐獠恐С中酒瞥晒ぷ饔?jì)算機(jī)。這樣就可以很容易的把單片機(jī)系統(tǒng)植入裝置內(nèi)部來控制裝置了

41、。近年來為了在指令和數(shù)據(jù)上使用不同的字寬，并提高處理器流水線速度，哈佛結(jié)構(gòu)在微控制器和DSP也逐漸得到了廣泛的應(yīng)用。 </p><p>　　傳統(tǒng)的微處理器是不允許這么做的。它要完成單片機(jī)的工作，就必須連接一些其他芯片。比如說，片上沒有數(shù)據(jù)存儲(chǔ)器，就必須要添加一些RAM的存儲(chǔ)芯片，雖然所添加存儲(chǔ)器的容量很靈活，但是至少還是要添加，另外還需要添加很多連線來傳遞芯片之間的數(shù)據(jù)。 比如，一個(gè)典型的微控制器只需要一個(gè)時(shí)鐘發(fā)

42、生器和很少的RAM和ROM(或者EPROM, E2PROM)就可以在軟件和晶振下工作了。同時(shí)，微控制器具有豐富的輸入輸出設(shè)備，像是模擬數(shù)字轉(zhuǎn)換(ADC)，定時(shí)器，串口或者其他串行通訊接口(比如I2C，串行外圍接口(SPI),控制器局域網(wǎng))。通常，這些繼承在內(nèi)部的設(shè)備可以通過特殊的指令來操作。 </p><p>　　一些現(xiàn)代的微控制器支持一些內(nèi)建的高級(jí)編程語言，比如BASIC語言。</p><p

43、>　　一個(gè)微控制器（也叫MCU）是一個(gè)微型計(jì)算芯片。它包含一個(gè)處理器、一個(gè)內(nèi)存（有少量的RAM ，程序存儲(chǔ)器，或兩者兼而有之）和一個(gè)可編程輸入/輸出外設(shè)。 </p><p>　　它強(qiáng)調(diào)高度集成，而相比之下，一個(gè)微處理器只包含一個(gè)CPU （比如一臺(tái)PC ） 。除了通常的算術(shù)和邏輯要素等一般用途的微處理器，微控制器還集成了更多的要素，如讀寫存儲(chǔ)器的數(shù)據(jù)存儲(chǔ)，只讀存儲(chǔ)器的存儲(chǔ)程序，快閃記憶體的永久數(shù)據(jù)存儲(chǔ)，外設(shè)，

44、和輸入/輸出接口。在時(shí)鐘頻率只有32Mhz的情況下 ，微操作系統(tǒng)往往以非常低的速度相運(yùn)行，但是這足夠典型的應(yīng)用。他們消耗較少的功率（毫瓦或什微） ，且具有保持功能，同時(shí)可以等待一個(gè)事件，如一個(gè)按鈕的按下或中斷。在睡眠狀態(tài)時(shí)， CPU時(shí)鐘和外設(shè)禁用，從而使它們適合用于低功耗和長期持久的電池應(yīng)用。 </p><p>　　微控制器廣泛應(yīng)用于自動(dòng)控制產(chǎn)品和設(shè)備，如汽車發(fā)動(dòng)機(jī)控制系統(tǒng)，遠(yuǎn)程控制系統(tǒng)，辦公室機(jī)器設(shè)備系統(tǒng)，家用

45、電器，電動(dòng)工具，和玩具等。通過降低尺寸，成本和能耗，設(shè)計(jì)使用單獨(dú)的微處理器，內(nèi)存和輸入/輸出設(shè)備，能夠使微控制器控制更多的進(jìn)程，更經(jīng)濟(jì)。</p><p>　　目前，大多數(shù)的計(jì)算機(jī)系統(tǒng)被嵌入在其他設(shè)備中使用，如汽車，電話以及很多需要外設(shè)的計(jì)算機(jī)系統(tǒng)。這些嵌入其他設(shè)備的計(jì)算機(jī)系統(tǒng)被稱為嵌入式系統(tǒng)。有些嵌入式系統(tǒng)是非常復(fù)雜的，很多能夠達(dá)到人們的要求，但由于內(nèi)存和程序長度的限制，軟件的復(fù)雜性降低。典型的輸入和輸出設(shè)備包括

46、交換機(jī)，繼電器，螺線管，發(fā)光二極管，小形或定制的液晶顯示器，數(shù)碼顯示器等。射頻設(shè)備和傳感器等嵌入式系統(tǒng)通常沒有鍵盤，屏幕，硬盤，打印機(jī)或其他公認(rèn)的I / O設(shè)備，并可能缺乏人機(jī)互動(dòng)裝置的任何一種。</p><p>　　某些強(qiáng)制性的微控制器能夠提供實(shí)時(shí)應(yīng)對(duì)突發(fā)事件的嵌入式系統(tǒng)并控制它們。當(dāng)某些事件發(fā)生時(shí)，中斷系統(tǒng)能夠讓信號(hào)處理器暫停處理當(dāng)前的指令序列，并開始了中斷服務(wù)。當(dāng)中斷服務(wù)結(jié)束之后，再返回原來的指令序列，這就

47、是我們通常所說的單片機(jī)的中斷系統(tǒng)。中斷源的設(shè)備依賴通常有很多種，如內(nèi)部定時(shí)器溢、完成了模擬向數(shù)字轉(zhuǎn)換、邏輯水平變化的一種投入、一個(gè)按鈕被按下和收到了數(shù)據(jù)的通信聯(lián)系等。凡是許多重要的中斷源發(fā)出中斷申請(qǐng)，都必須中斷，如電池供電的設(shè)備停止運(yùn)行后，微控制器在低功耗睡眠狀態(tài)下的處理器必須停止，直到做一些外圍的活動(dòng)才重新開始返回當(dāng)前指令序列。</p><p>　　單片機(jī)程序必須符合現(xiàn)有的芯片程序存儲(chǔ)器的要求，因?yàn)檫@將是代價(jià)高

48、昂的系統(tǒng)提供了與外部設(shè)備之間可以擴(kuò)展的存儲(chǔ)器。編譯器和匯編語言是用來打開高級(jí)語言程序到一個(gè)緊湊機(jī)器代碼存儲(chǔ)在微控制器的存儲(chǔ)過程。根據(jù)不同的設(shè)備，程式記憶體可能是永久性的，而唯讀存儲(chǔ)器，只能進(jìn)行編程。在工廠，可以生產(chǎn)可擦除式只讀存儲(chǔ)器。</p><p>　　由于嵌入式處理器通常是用來控制設(shè)備的，他們有時(shí)需要接受輸入設(shè)備的數(shù)據(jù)輸入，但由于處理器內(nèi)置處理數(shù)數(shù)據(jù)只有1和0 ，所以它們將無法直接處理任何模擬信號(hào)。因此，要先

49、使需要處理的數(shù)據(jù)通過模擬向數(shù)字轉(zhuǎn)換的過程，才能使傳入的數(shù)據(jù)轉(zhuǎn)化為處理器可以識(shí)別的形式。還有一種轉(zhuǎn)換器叫做數(shù)模轉(zhuǎn)換器，他能夠使數(shù)字信號(hào)轉(zhuǎn)換為模擬信號(hào)并將數(shù)據(jù)發(fā)送到需要CPU控制的設(shè)備上，以達(dá)到控制的目的。</p><p>　　此外，許多嵌入式微處理器包括各種兼職的轉(zhuǎn)換器。最常見的一種類型的轉(zhuǎn)換器是可編程間隔定時(shí)轉(zhuǎn)換器。工作過程為一個(gè)倒計(jì)時(shí)剛到達(dá)零，它就會(huì)對(duì)處理器發(fā)出一個(gè)中斷的指令。這表明它已經(jīng)完成轉(zhuǎn)換，并需要對(duì)所控