单片机外文文献翻译

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沈阳工程学院毕业设计(论文)外文文献一单片机简介单片机是一种集成在电路芯片,是采用超大规模集成电路技术把具有数据处理能力的中央处理器CPU随机存储器RAM、只读存储器ROM、多种I/O口和中断系统、定时器/计时器等功能(可能还包括显示驱动电路、脉宽调制电路、模拟多路转换器、A/D转换器等电路)集成到一块硅片上构成的一个小而完善的计算机系统。单片机也被称为微控制器(Microcontroller),是因为它最早被用在工业控制领域。单片机由芯片内仅有CPU的专用处理器发展而来。最早的设计理念是通过将大量外围设备和CPU集成在一个芯片中,使计算机系统更小,更容易集成进复杂的而对体积要求严格的控制设备当中。INTEL的Z80是最早按照这种思想设计出的处理器,从此以后,单片机和专用处理器的发展便分道扬镳。二、单片机的发展趋势现在可以说单片机是百花齐放,百家争鸣的时期,世界上各大芯片制造公司都推出了自己的单片机,从8位、16位到32位,数不胜数,应有尽有,有与主流C51系列兼容的,也有不兼容的,但它们各具特色,互成互补,为单片机的应用提供广阔的天地。 纵观单片机的发展过程,可以预示单片机的发展趋势,大致有: 1.低功耗CMOS MCS-51系列的8031推出时的功耗达630mW,而现在的单片机普遍都在100mW左右,随着对单片机功耗要求越来越低,现在的各个单片机制造商基本都采用了CMOS(互补金属氧化物半导体工艺)。象80C51就采用了HMOS(即高密度金属氧化物半导体工艺)和CHMOS(互补高密度金属氧化物半导体工艺)。CMOS虽然功耗较低,但由于其物理特征决定其工作速度不够高,而CHMOS则具备了高速和低功耗的特点,这些特征,更适合于在要求低功耗象电池供电的应用场合。所以这种工艺将是今后一段时期单片机发展的主要途径。 2.微型单片化 现在常规的单片机普遍都是将中央处理器(CPU)、随机存取数据存储(RAM)、只读程序存储器(ROM)、并行和串行通信接口,中断系统、定时电路、时钟电路集成在一块单一的芯片上,增强型的单片机集成了如A/D转换器、PMW(脉宽调制电路)、WDT(看门狗)、有些单片机将LCD(液晶)驱动电路都集成在单一的芯片上,这样单片机包含的单元电路就更多,功能就越强大。甚至单片机厂商还可以根据用户的要求量身定做,制造出具有自己特色的单片机芯片。 此外,现在的产品普遍要求体积小、重量轻,这就要求单片机除了功能强和功耗低外,还要求其体积要小。现在的许多单片机都具有多种封装形式,其中SMD(表面封装)越来越受欢迎,使得由单片机构成的系统正朝微型化方向发展。 3.主流与多品种共存 现在虽然单片机的品种繁多,各具特色,但仍以80C51为核心的单片机占主流,兼容其结构和指令系统的有PHILIPS公司的产品,ATMEL公司的产品和中国台湾的Winbond系列单片机。所以C8051为核心的单片机占据了半壁江山。而Microchip公司的PIC精简指令集(RISC)也有着强劲的发展势头,中国台湾的HOLTEK公司近年的单片机产量与日俱增,与其低价质优的优势,占据一定的市场分额。此外还有MOTOROLA公司的产品,日本几大公司的专用单片机。在一定的时期内,这种情形将得以延续,将不存在某个单片机一统天下的垄断局面,走的是依存互补,相辅相成、共同发展的道路。三、仿真器的发展纵观国内近二十年的仿真技术发展历程,根据仿真器使用的技术来划分,国内仿真器的设计大约可以分成以下几个时期:(1) 70年代末期-80年代中期这个时期采用的技术主要是仿真开发系统,现在看来技术含量不高,用户要求也不高。(2) 80年代末期-90年代末期这个时期主要使用华邦一颗带有仿真功能的芯片制作,采用的技术叫做Bondout。采用这颗芯片能大大简化仿真器的设计,因此国内仿真器的水准有了大的提高,基本上可以不占用用户资源。正是由于仿真性能的提高,国内的仿真器制作在将近10年的时间内没有进步,一直采用这种制作模式。虽然个别厂商也尝试过别的技术来提高仿真水准,例如HOOKS技术,但是由于本身技术的限制没有成功。相反国外的仿真器较早地使用了HOOKS技术,在初期由于HOOKS技术本身的复杂性,仿真性能和价格不如国内采用Bondout的仿真器。随着IC技术的发展,国内制作HOOKS技术的条件已经成熟,但是国内的几家主要的生产厂商还陶醉于Bondout技术之中。(3) 2000年开始2000年是中国仿真器市场变化最大的时期,其中最引人注目的变化是华邦仿真芯片W78958的停产。华邦公司在设计W78958芯片时,其内部的仿真功能只是为了仿真器厂商能制作仿真器以便更好的推广W78958。但是经过几年的变化,W78958演变成为一颗仿真器上使用的仿真专用芯片而不是用户使用的标准芯片,使用的范围也仅限于国内,一年不到20000只的用量也促使华邦公司在进入2002年后宣布将停产该芯片。W78958停产以后,国内仿真器厂商处于一个非常尴尬的局面。由于W78958在国内使用了将近10年,国内的用户群非常庞大,这些用户将无法得到持续的支持特别是维修方面。另外,国内围绕在W78958上所做的技术工作也无法得到延续和提高,很多业界人士认为仿真器行业将面临另起炉灶或重新洗牌的局面。HOOKS技术无疑是仿真器厂商在失去W78958后的替代品,但是由于没有长期跟踪和关注,短期内多数厂家无法将复杂的HOOKS技术应用于成熟的产品中。专家们认为仿真器厂家的整体转型可能需要23年的周期,并且有相当的仿真器厂家将会被淘汰,市场拥有量将主要集中在少数几个仿真器厂家。随着芯片厂家越来越多、资源越来越强,用甲厂芯片去仿真乙厂芯片的兼容仿真模式,存在资源覆盖不全(如附加端口、附加外部中断)、地址分布不同(如P4口)、操作方式不同(如EXTRAM、WTD)等缺点。 用专用仿真芯片或Philips芯片去仿真20多个厂家的400多种芯片,所需的仿真头越来越多,因此有了新一代专利技术的仿真器。但是新一代专利技术的仿真器却使没有什么经济能力的初学者无力购买。四、以单片机为核心的嵌入式系统单片机的另外一个名称就是嵌入式微控制器,原因在于它可以嵌入到任何微型或小型仪器或设备中。目前,把单片机嵌入式系统和Internet连接已是一种趋势。但是,Internet一向是一种采用肥服务器,瘦用户机的技术。这种技术在互联上存储及访问大量数据是合适的,但对于控制嵌入式器件就成了杀鸡用牛刀了。要实现嵌入式设备和Int ernet连接,就需要把传统的Internet理论和嵌入式设备的实践都颠倒过来。为了使复杂的或简单的嵌入式设备,例如单片机控制的机床、单片机控制的门锁,能切实可行地和Internet连接,就要求专门为嵌入式微控制器设备设计网络服务器,使嵌入式设备可以和Internet相连,并通过标准网络浏览器进行过程控制。 目前,为了把单片机为核心的嵌入式系统和Internet相连,已有多家公司在进行这方面的较多研究。这方面较为典型的有emWare公司和TASKING公司。 EmWare公司提出嵌入式系统入网的方案-EMIT技术。这个技术包括三个主要部分:即emMicro, emGateway和网络浏览器。目前,单片机应用中提出了一个新的问题:这就是如何使8位、16位单片机控制的产品,也即嵌入式产品或设备能实现和互联网互连? TASKING公司目前正在为解决这个问题提供了途径。该公司已把emWare的EMIT软件包和有关的软件配套集成,形成一个集成开发环境,向用户提供开发方便。五 单片机应用的可靠性技术发展 在单片机应用中,可靠性是首要因素为了扩大单片机的应用范围和领域,提高单片机自身的可靠性是一种有效方法。近年来,单片机的生产厂家在单片机设计上采用了各种提高可靠性的新技术,这些新技术表现在如下几点: 1、EFT(Ellectrical Fast Transient)技术 EFT技术是一种抗干扰技术,它是指在振荡电路的正弦信号受到外界干扰时,其波形上会迭加各种毛刺信号,如果使用施密特电路对其整形,则毛刺会成为触发信号干扰正常的时钟,在交替使用施密特电路和RC滤波电路时,就可以消除这些毛否则令其作用失效,从而保证系统的时钟信号正常工作。这样,就提高了单片机工作的可靠性。Motorola公司的 MC68HC08系列单片机就采用了这种技术。 低噪声布线技术及驱动技术 在传统的单片机中,电源及地线是在集成电路外壳的对称引脚上,一般是在左上、右下或右上、左下的两对对称点上。这样,就使电源噪声穿过整块芯片,对单片机的内部电路造成干扰。现在,很多单片机都把地和电源引脚安排在两条相邻的引脚上。这样,不仅降低了穿过整个芯片的电流,另外还在印制电路板上容易布置去耦电容,从而降低系统的噪声。 现在为了适应各种应用的需要,很多单片机的输出能力都有了很大提高,Motorola公司的单片机I/O口的灌拉电流可达8mA以上,而Microchip公司的单片机可达25mA。其它公司:AMD,Fujitsu,NEC ,Infineon,Hitachi,Ateml,Tosbiba等基本上可达820mA的水平。这些电流较大的驱动电路集成到芯片内部在工作时带来了各种噪声,为了减少这种影响,现在单片机采用多个小管子并联等效一个大管子的方法,并在每个小管子的输出端串上不同等效阻值的电阻,以降低di/dt,这也就是所谓跳变沿软化技术,从而消除大电流瞬变时产生的噪声。 2、采用低频时钟 高频外时钟是噪声源之一,不仅能对单片机应用系统产生干扰,还会对外界电路产生干扰,令电磁兼容性不能满足要求。对于要求可靠性较高的系统,低频外时钟有利于降低系统的噪声。在一些单片机中采用内部琐相环技术,则在外部时钟较低时,也能产生较高的内部总线速度,从而保证了速度又降低了噪声。Motorola公司的MC68HC08系列及其1 6/32位单片机就采用了这种技术以提高可靠性Foreign documents一 Microcontroller introductionSCM is A kind of integrated circuit chips, is to use very large scale integrated circuit technology has the ability to handle data CPU CPU, RAM random access memory read only memory ROM, A variety of I/O mouth and interrupt system, timer/timer function (may include display driver circuit, pulse width modulation circuit, simulation way more converter, A/D converter circuits, etc) integrated into one of these forms of A small and perfect computer system.SCM is also called micro controller (Microcontroller), because it was the first used in the industrial control area. By chip microcontroller within the CPU only dedicated processor. The first design concept is through the huge amounts of peripheral and CPU integration in a chip, make the computer system more small, more easily integrated into the complex and demanding to volume control of equipment. The INTEL Z80 is the earliest according to this design thought of the processor, and from then on, SCM and dedicated processor development and separate.二 The development trend of the single chip microcomputerNow can say MCU is let flowers blossom and schools of thought contend period, the world each big chip manufacturing companies have launched their own microcontroller, from 8 bits, 16 to 32 bit, countless, everything, and the mainstream C51 series compatible, also have compatible, but they have their special features, complementary to each other, for the application of the single chip microcomputer provide vast heaven and earth.Throughout the development process of single chip microcomputer, predicts the development trend of the single chip microcomputer, roughly:1Low power consumption CMOSMCS-51 series of 8031 when the power consumption of the launch of the 630 mW, but now the single chip microcomputer universal in 100 mW or so, as the SCM power consumption demand more and more low, each single chip manufacturers now basic using CMOS (complementary metal oxide semiconductor process). Like 80 C51 had adopted HMOS (namely high density metal oxide semiconductor technology) and CHMOS (high density complementary metal oxide semiconductor process). Though low power consumption CMOS, but because of its physical characteristics to determine the speed of work is not quite high, and CHMOS is the high speed and have the characteristics of low power consumption, these characteristics and is more suitable for low power consumption in demand like battery power applications. So this process will be for a period of the development of the single chip microcomputer main ways2Miniature sheet piece ofNow the single chip microcomputer universal conventional is will the central processing unit (CPU), random access memory (RAM), data read only memory (ROM) program, parallel and serial communication interface, the interrupt system, regular circuit, clocking circuit integration in A single chip, enhanced the single chip micro computer integrated as A/D converter, PMW (pulse width modulation circuit), WDT (watchdog), some SCM LCD (LCD) will drive circuit are integrated in A single chip, this single chip unit circuit will contain more, function, the stronger you will be. Even single chip manufacturer still can be customized according to the users requirements, make its own characteristics of single chip microcomputer chip. In addition, the products now universal demand small volume, light weight, which requires the single-chip microcomputer besides function is strong and low power consumption, but also to ask its volume to small. Many of the single chip microcomputer now has a variety of packaging forms, including SMD surface packaging) has become more and more popular, makes the system constructed by single-chip microcomputer is the development direction in miniaturization.3The mainstream and many kinds of coexistenceNow, while the single chip microcomputer variety, each characteristic, but still with 80 C51 single chip microcomputer as the core of the mainstream, compatible with its structure and instructions of the system PHILIPS products, ATMEL company products and China Taiwans Winbond series microcontroller. So as the core of the single chip microcomputer occupy C8051 heavily-accented screams. Microchip company and the PIC reduced instruction set (RISC) also have a strong momentum of development, China and Taiwan HOLTEK company in recent years of the single chip micro computer output grows day by day, and the advantages of high quality and low price, takes up the market share. In addition to MOTOROLA the product of the company, a few big companies for the Japanese microcontroller. In a certain period of time, this kind of situation will to continue, there wont be a single chip microcomputer skillfulness of monopoly situation, go is dependent complementary, supplement each other and common development road.三The development of the simulatorThroughout the domestic nearly 20 years of simulation technology development course, according to the simulation implement use technology to differentiate, the design of the domestic simulator can be divided into the following several period about:(1) 70 s-the mid 80sThis period is mainly the adopted technology of the simulation system development, and now it is not high technical content, user requirements is not high also.(2) the 80 s-90 sThis period mainly use HuaBang a simulation of production function with chip, using technology called Bondout. Adopting the single chip can greatly simplified the design of the simulation system, therefore the domestic simulators level have improved, basically can do not take up the user resources.It is due to the improvement of the performance of the simulation, the domestic simulator in nearly 10 years of making time no progress, has been using this kind of production mode. Although individual manufacturer has also tried other technology to improve simulation level, such as HOOKS technology, but because of its technical limitations without success. Instead of foreign simulators early use HOOKS technology, in early because of the complexity of the HOOKS technology itself, the simulation performance and price as the domestic Bondout simulation device.Along with the IC technology development, the domestic production of the HOOKS technology conditions ripe, but domestic several major production manufacturer still lose themselves in Bondout technology in.(3) started in 20002000 is the Chinese simulators market change is the biggest period, one of the most dramatic change is HuaBang simulation chip W78958 shut-down.Sinocon corp. In W78958 chip design, its internal simulation function just for simulators manufacturers can make simulator in order to better promote W78958. But after years of change, W78958 evolved into a simulation device on the use of the special chip simulation and not users with the use of the standard chip, the scope of use for domestic, less than a year the dosage of only 20000 prompted sinocon corp. In the 2002 years later announced it will stop production the chip.W78958 after production, domestic simulation device manufacturers in a very embarrassing situation. Because in the domestic use W78958 nearly 10 years, domestic user group of very large, these users will not be able to get the ongoing support especially maintenance. In addition, China has done in W78958 around the technical work will be given continue and improve, many professionals think simulators industry will face the drawing board or to shuffling of the situation.HOOKS technology is undoubtedly simulator in W78958 lost after the manufacturer substitute, but with no long-term tracking and attention, the short term most manufacturers cant will complex HOOKS technology applied to mature product. Experts think the whole transformation of the manufacturer may need to 2-3 year cycle, and so is the simulation of the factory will be eliminated, the market will be mainly the ownership in a few simulation device manufacturers.As the more and more manufacturers, resource is more and more strong, with JiaChang chip to the simulation YiChang chips compatible simulation model, existing resources does not cover all (such as additional port, additional external interruption), address distribution different (such as P4 mouth), the operation mode different (such as EXTRAM, WTD) shortcomings. Use special simulation chip or Philips chip to the simulation of a variety of more than 20 factory 400 chip, the simulation head is more and more, so have a new generation of patent technology emulator.But a new generation of patent technology of the simulator will make no economic ability unable to buy the beginners.四With the single chip processor as the core of the embedded systemSCM another name is embedded microcontroller controller, the reason is that it can be embedded into any miniature or small instrument or equipment. At present, the single chip embedded system and Internet connection is a kind of trend. But, the Internet has always been a server with fat, thin users machine technology. The technology of the Internet in the storage and access to large amounts of data is appropriate, but for control embedded devices became kill chicken por muson mortigi oni pafiloro ne uzas. To realize the embedded equipment and Int ernet connection, it needs to put the traditional Internet theory and the practice of embedded system is upside down. In order to make the complex or simple embedded devices, such as single chip microcomputer control machine tools, single chip microcomputer control locks, can feasible and Internet connection, it requires special equipment for embedded microcontroller controller design web server, make embedded devices can be and Internet connected, and through the standard web browser process control.At present, in order to put the single chip microcomputer as the core of the embedded system and Internet connected, has had a lot of companies in the more research. This aspect of the typical have emWare company and TASKING company. EmWare company to put forward the embedded system of the program-the net EMIT technology. This technology includes three main parts: that is emMicro, emGateway and a web browser. At present, the SCM put forward a new problem: this is how to make eight, 16 single-chip microcomputer control products, namely embedded products or equipment can realize interconnection and the Internet? TASKING company is currently to solve this problem provides way. The company has the emWare EMIT the software package and relevant software integration of form a complete set, forming an integrated development environment, to facilitate the development of the users.五 The reliability of the microcomputer application technology developmentIn the single chip microcomputer applications, the reliability is the primary factor in order to expand the application range of the single chip microcomputer and field, improve the reliability of the single chip microcomputer itself is a kind of effective method. In recent years, the single chip manufacturers in the design of the single chip microcomputer to improve reliability of the new technology, the new technology performance in the following:(1) EFT (Ellectrical Fast Transient) technologyEFT technology is a kind of anti-interference technology, it is to point to in the oscillating circuit by the sine signal interference, the waveform superposition of burr signal will, if use the plastic schmidt circuit, the burr would be triggered signals interferes with normal clock, in the alternate use schmidt circuit and the RC filter circuit, can eliminate the hair or make its function failure to ensure system clock signal normal work. So, improve the reliability of the single chip microcomputer. Motorola company MC68HC08 series microcontroller adopt the technology. Low noise wiring technology and drive technologyIn the traditional single chip microcomputer, the power and the ground is in integrated circuit of the shell of ChenYin feet, general is in the upper left, right or at the lower left, two for symmetry point. It is, it makes the power supply noise through the whole chip, the SCM internal circuit cause interference. Now, a lot of the single chip microcomputer and power pin arranged in two adjacent pin. So, not only reduces the through the chip of the current, and also in the printed circuit board to decorate its decoupling capacitor, so as to reduce the noise of the system. In order to adapt to all kinds of application of now need, a lot of the single chip microcomputer output ability all had the very big enhancement, the single chip microcomputer Motorola company I/O mouth filling the pull current can reach 8 mA above, and Microchip company single-chip to 25 mA. Other companies: AMD, Fujitsu, NEC, Infineon, Hitachi, Ateml, such as Tosbiba basically can reach 8 20 mA level. The current larger drive circuit integration to chip in work internal causes all sorts of noise, in order to reduce the influence, now more than the small tube single chip parallel equivalent a large pipes method, and in every little the pipe string, the output terminal of the different equivalent resistance of resistance to reduce di/dt, this also is the so-called jump to change along the softening technology, so as to eliminate large current transient produced by the noise.(2)the low frequency clockThe clock is one of high frequency noise sources, not only can the disturbance of SCM system, and also to the outside world circuitry interference and make the electromagnetic compatibility cant meet the requirements. Asking for high reliability system, the low frequency clock which helps reduce system noise. In some of the single chip microcomputer by internal zohar cirtle technology, is in the external clock is low, also can produce high internal bus speed, and thus makes the speed and reduce the noise. The company MC68HC08 series Motorola and its 1 6/32 a single chip adopt the technology to improve reliability
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