外文翻译基于单片机的智能电风扇控制系统

外文原文

Single-chip microcomputer

1. the introduction of the singlechip microcomputer

The singlechip is one kind of integrated circuit chip, which uses the ultra large-scale technology and has the data-handling capacity (for example arithmetic operation, logic operation, data transfer, interrupt processing) the microprocessor (CPU), random access data-carrier storage (RAM), read-only program memory (ROM), input output circuit (I/O), possibly also includes fixed time the counter, serial passes unguardedly (SCI), demonstration actuation electric circuit (LCD or LED actuation electric circuit), pulse-duration modulation electric circuit (PWM), simulation multichannel switch and A/Electric circuit and so on D switch integrates to together the monolith chip on, constitutes to be smallest the computer system which however consummates. These electric circuits can under the software control accurate, be rapid, highly effective complete the procedure designer preset the duty. From this looked that, singlechip has the function which the microprocessor does not have, it may alone complete the intellectualization control function which the modern industry control requests, this is singlechip biggest characteristic. However singlechip also is different with the single trigger, the chip before the development, it only has the function greatly strengthened ultra large scale integrated circuit, if entrusts with it the specific procedure, it then is youngest, the integrity microcomputer control system, it (PC machine) has the essential difference with the single trigger or the personal computing, singlechip application belongs to the chip level application, needs the user to understand singlechip chip the structure and the command system as well as other integrated circuit application technologies and the system design need theory and technology, with such specific chip design application procedure, thus causes this chip to have the specific function.

The different singlechip has the different hardware characteristic and the software characteristic, namely their technical characteristic is different, the hardware characteristic is decided by singlechip chip internal structure, the user must use some kind of singlechip, must understand whether this product does satisfy the characteristic target which the need the function and the application system requests. Here technical characteristic including function characteristic, control characteristic and electrical specification and so on, these information needs to obtain from in theproduction merchant technical manual. The software characteristic is refers to the command system characteristic and the development support environment, the instruction characteristic is singlechip addressing way which we is familiar with, the data

processing and the logical processing way, input-output characteristic and to power source request and so on. The development support environment is compatible and the probability including the instruction, supports the software (to contain may support development application procedure software resources) and the hardware resources. Must use some model singlechip to develop own application system, master its structure characteristic and the technical characteristic is that we need.. Singlechip control system could substitute for before uses control system which the complex electronic circuit or the digital circuit constituted, might the software control realizes, and could realize the intellectualization, now singlechip control category omnipresent, for example correspondence product, domestic electric appliances, intelligent instrument measuring appliance, process control and special-purpose control device and so on, singlechip application domain was more and more widespread. Indeed, singlechip application significance is far is not restricted in its application category or from this the economic efficiency which brings, it fundamentally changed the traditional control method and the design thought more importantly. Is controls technical a revolution, is an important milestone.

2.The MCU’s development outline

In 1946 first electronic accounting machine birth until now, only then 50 years, depends upon microelectronic technology and the semiconductor technology progress, from the electron tube - transistor- integrated circuit - large scale integrated circuit, now together on the chip definitely may integrate several million even more than ten million transistor, causes the computer volume slightly, the function is stronger. Specially in the nearly 20 years time, computer technology obtained the rapid development, the computer in the industry and agriculture, the scientific research, the education, the national defense and the aerospace domain has obtained the widespread application, computer technology already was a national modern science and technology level important symbol.

Singlechip is born in the 20th century 70's, looks like F8 monolithic microcomputer which Fairchid Corporation develops. The so-called singlechip is uses the large scale integrated circuit technology the central processing element (Center Processing Unit, Also is Chang Cheng CPU) and the data-carrier storage (RAM), theprogram memory (ROM) and other I/O passes integrates unguardedly on together the chip, constitutes a smallest computer system, but modern singlechip then has added on the severance unit, fixed time unit and A/D transformation and so on more complex, more perfect electric circuit, causes singlechip the function more and more formidable, the application is more widespread.

The 20th century 70's, microelectronic technology is being at the development phase, the integrated circuit belongs to the scale development time, each kind of new material new craft

not yet mature, singlechip still occupied the primary development phase, the part integration scale also quite small, the function quite was simple, CPU, RAM had generally has also included some simple I/O integrates to the chip on, looks like Farichild Corporation to belong to this type, it also must be joined to the periphery other processing electric circuits just now to constitute the integrity the computing system. The similar singlechip also has Zilog Corporation the Z80 microprocessor. In 1976 INTEL Corporation has promoted the MCS-48 singlechip, this time singlechip is the genuine 8 monolithic microcomputers, and pushes to the market. It is young by the volume, function entire, the price has lowly won the widespread application, has laid the foundation for singlechip development, becomes in singlechip history the important milestone. Under the MCS-48 leadership, after that, each big semiconductor company developed and has developed own singlechip one after another, looked like Zilog Corporation the Z8 series.

To the beginning of the 80's, singlechip has developed to the high performance stage, looks like INTEL Corporation the MCS-51 series, Motorola Corporation 6,801 and 6,802 series, Rokwell Corporation 6,501 and 6,502 series and so on, In addition,Japan's famous electrical company NEC and HITACHI all one after another developed had oneself characteristic the special-purpose singlechip. The 80's, world each big company competes to develop the variety multi-purpose strong singlechip, some severaldozens series, more than 300 varieties, this time singlechip belongs approximately truely monolithic, mostly integrated CPU, RAM, ROM, number many I/O connection, many kinds of interruption system, even also has some to bring A/D switch singlechip, function more and more formidable, RAM and ROM capacity also more and more big, the addressing space even may reach 64kB, may say, singlechip developed to a brand-new stage, the application domain has beenmore widespread, many domestic electric appliances moved towards the intellectualized development path which controlled using singlechip. After 1982, 16 singlechips are published, represent the product are INTEL Corporation's MCS-96 series, 16 singlechips compare 8 machine, the data width increased a time, real-time processing ability stronger, the basic frequency is higher, the integration rate had achieved 120,000 transistors, RAM increased to 232 bytes, ROM then has achieved 8kB, and had 8 interrupt sources, at the same time has disposed multichannel A/D transformation channel, high speed I/The O processing unit, is suitable for the more complex control system.

After 90's, singlechip obtained the rapid development, the world each big semiconductor company has developed a function more formidable singlechip one after another. American Microchip Corporation had issued one kind of incompatible MCS-51 new generation of PIC series singlechip, has aroused the field widespread interest completely, its

product only then 33 simplified the set of instructions to attract many users specially, caused the people to concentrate from the INTEL 111 complex instructions. The PIC singlechip has obtained the fast development, holds the small space in the field. The afterwards matter, the familiar singlechip public figures quite have been all clear, more monolithic aircraft types pour out, MOTOROLA Corporation had issued one after another the MC68HC series singlechip, Japan's several famous companies all developed a performance stronger product, but Japan's singlechip used in generally the special-purpose systems control, but did not look like company and so on INTEL puts in to the market forms the general singlechip. For example NEC Corporation produces the uCOM87 series singlechip, its representative works uPC7811 is one kind of performance quite outstanding singlechip. MOTOROLA Corporation's characteristic and so on MC68HC05 series its high speed low price has won many users. Zilog Corporation's Z8 series product representative works are Z8671, contains BASIC the Debug interpreter, enormous place then user. But American country half COP800 series singlechip then uses the advanced Harvard structure. ATMEL Corporation then perfectly unifies singlechip technology and the advanced Flash memory technology, has issued the performance quite outstanding AT89 series singlechip. Including company and so on China's Taiwan HOLTEK and WINBOND in abundance has also joined singlechip development ranks, by reason of their inexpensive superiority, shares cup of beautiful thick soup.In 1990 American INTEL Corporation promoted 80,960 super 32 singlechips to cause the computer stir, the product has put in the market one after another, became in singlechip history an important milestone. This period, in singlechip field, singlechip variety extraordinary splendour, competes to be the most unusual. Some 8, 16 even 32 machine, but 8 singlechips by its price inexpensive, the variety complete, the application software rich, the support environment were still full, characteristic and so on development convenience but are occupying the dominant position. But INTEL Corporation by reason of their abundant technology, the performance outstanding type and the good foundation, at present was still singlechip mainstream product. Only is the 90's intermediate stages, INTEL Corporation is busy is developing their personal computing microprocessor, not the enough energy continued singlechip technology which develops oneself creates leads, but by company and so on PHILIPS continues to develop the C51 series singlechip.

3.Singlechip application domain

Singlechip widely applies in the instrument measuring appliance, the domestic electric appliances, the medical equipment, domain and so on aerospace, special purpose equipment intellectualized management and process control, may divide the following several categories approximately:

(1). On intelligent instrument measuring appliance application

Singlechip has the volume small, the power loss low, the control function strong, the expansion is nimble, merit and so on microminiaturization and easy to operate, widely applies in the instrument measuring appliance, the union different type sensor, may realize such as physical quantity the and so on voltage, power, frequency, humidity, temperature, current capacity, speed, thickness, angle, length, degree of hardness, element, pressure survey. Uses singlechip control to cause the instrument measuring appliance digitization, the intellectualization, the microminiaturization, also the function compares uses the electron or the digital circuit is more formidable. For example precise measurement equipment (dynamometer, oscilloscope, each kind of analyzer).

(2). In industry control application

May constitute the various formats control system, the data acquisition system with singlechip. For example the factory assembly line intellectualized management, the elevator intellectualization control, each kind of alarm system, constitutes two cascade control systems with the computer networking and so on.

(3).In domestic electric appliances application

May say like this that, the present domestic electric appliances basically have all used singlechip control, praised, the washer, the electric refrigerator, the air conditioner, the color television, other acoustic video frequency equipments from the electricity food, again to the electronic weighting equipment, all kinds of, omnipresent.

(4).In computer network and correspondence domain application

Of the modern singlechip has the correspondence connection generally, may very conveniently and the computer carries on the data communication,for provided the extremely good physical conditions application in between the computer network and the communication facility, the present communication facility basically has all realized singlechip intelligence control, from the handset, the telephone, the small program controlled switch, the building automatic correspondence ringing system, the train wireless correspondence, again the mobile phone which everywhere to the routine work in, the colony mobile communication, radio intercom and so on.

(5).Singlechip in medical equipment domain application

Singlechip quite is also widespread inmedical equipment use, for example medical life-support machine, each kind of analyzer, , ultrasound diagnosis equipment and hospital bed ringing system and so on. In addition, singlechip in the industry and commerce, the finance, the scientific research, the education, domain and so on national defense aerospace all has the extremely widespread use.

4.Singlechip development tendency

Now may say singlechip was all flowers blooms together, the time which hundred school of thought contended, in the world each big chip manufacture company has all promoted own singlechip, from 8, 16 to 32, innumerable, had everything expected to find, has compatibly with the mainstream C51 series, also had not not compatibly, but they unique, became mutually supplementarily, provided the broad world for singlechip application. Looks over singlechip developing process, may indicate singlechip development tendency, has approximately:

(1). Low power loss CMOS

The MCS-51 series 8,031 promotes when the power loss reaches 630mW, but the present singlechip all about 100mW, along with more and more is generally low to singlechip power loss request, the present each singlechip manufacturer basic has all used CMOS (complementary metal oxide semiconductor craft). Looked like

80C51 to use HMOS (namely high density metal oxide compound semiconductor craft) and CHMOS (supplementary high density metal oxide compound semiconductor craft). CMOS although power loss low, but because its physical characteristic decides its working speed insufficiently high, but CHMOS then had has been high speed and the low power loss characteristic, these characteristics, suited in are requesting the low power loss likely battery power supply the application situation. Therefore this kind of craft will be the main way which the next section of times singlechip will develop.

(2). Miniature monolithic

Now the conventional singlechip all is generally the central processor (CPU), the random access data storage (RAM), the read-only program memory (ROM), parallel and the serial communication connection, the interruption system, the timing circuit, the clock electric circuit integration on together the sole chip, the enlargement mode singlechip integrated like A/The D switch, PMW (pulse-duration modulation electric circuit), WDT (watch-dog), some singlechips (liquid crystal) actuate LCD the electric circuit all to integrate on the sole chip, such singlechip contains unit electric circuit more, the function is more formidable. Even singlechip merchant also may act according to the user requiremnet the body custom make, makes has oneself characteristic singlechip chip. In addition, present product universal demand volume small, weight light, this requests singlechip strong and the power loss is low besides the function, but also requests its volume to have to be small. Present many singlechips all have the many kinds of seals form, SMD (superficial seal) more and more receives welcome, to enable the system which constitutes by singlechip towards the microminiaturized direction to develop.

(3).Mainstream and multi- varieties coexistence

Now although singlechip variety is many, unique, but still as the core singlechip occupies the mainstream take 80C51, the compatible its structure and the command system have PHILIPS Corporation the product, the ATMEL Corporation's product and the Chinese Taiwan's Winbond series singlechip. Therefore C8051 was the core singlechip occupied the half of the country. But Microchip Corporation's PIC simplified the set of instructions (RISC) also to have the strong development tendency, the Chinese Taiwan's HOLTEK Corporation recent years singlechip output grows day by day, if the low price nature superior superiority, occupied a certain market minute volume. In addition also has MOTOROLA Corporation the product, the Japaneseseveral big companies' special-purpose singlechips. In the certain time, this kind of situation will be able to continue, will not have the monopoly aspect which some singlechip unified, will walk will be depends on for existence supplementarily, will complement one another, the communal development path.

中文翻译

单片机

1. 单片机介绍

单片机是一种集成电路芯片，应用超大规模技术把具有数据处理能力(如算术运算，逻辑运算、数据传送、中断处理)的微处理器(CPU)，随机存取数据存储器(RAM)，只读程序存储器(ROM)，输入输出电路(I/O口)，可能还包括定时计数器，串行通信口(SCI)，显示驱动电路(LCD 或 LED 驱动电路)，脉宽调制电路(PWM)，模拟多路转换器A/D 转换器等电路集成到一块单块芯片上,构成一个最小然而完善的计算机系统。这些电路能在软件的控制下准确、迅速、高效地完成程序设计者事先规定的任务。由此来看，单片机有着微处理器所不具备的功能，它可单独地完成现代工业控制所要求的智能化控制功能，这是单片机最大的特征。然而单片机又不同于单板机，芯片在没有开发前，它只是有着极强功能的超大规模集成电路，如果赋予它特定的程序，它便是一个最小的、完整的微型计算机控制系统，它与单板机或个人电脑(PC机)有着本质的区别，单片机的应用属于芯片级应用，需要用户了解单片机芯片的结构和指令系统以及其它集成电路应用技术和系统设计所需要的理论和技术，用这样特定的芯片设计应用程序，从而使该芯片具备特定的功能。

不同的单片机有着不同的硬件特征和软件特征，即它们的技术特征均不尽相同,而硬件特征取决于单片机芯片的内部结构，用户要使用某种单片机，必须了解该型产品是否满足需要的功能和应用系统所要求的特性指标。这里的技术特征包括功能特性、控制特性和电气特性等等，这些信息需要从生产厂商的技术手册中得到。软件特征是指指令系统特性和开发支持环境，指令特性即我们熟悉的单片机的寻址方式，数据处理和逻辑处理方式，输入输出特性及对电源的要求等等。开发支持的环境包括指令的兼容及可移植性，支持软件(包含可支持开发应用程序的软件资源)及硬件资源。要利用某型号单片机开发自己的应用系统，掌握其结构特征和技术特征是必须的。单片机控制系统能够取代以前利用复杂电子线路或数字电路构成的控制系统，可以由软件控制来实现，并能够实现智能化，现在单片机控制范畴无所不在，例如通信产品、家用电器、智能仪器仪表、过程控制和专用控制装置等等，单片机的应用领域越来越广泛。诚然，单片机的应用意义远不限于它的应用范畴或由此带来的经济效益，更重要的是它已从根本上改变了传统的控制方法和设计思想。是控制技术的一次革命，是一座重要的里程碑。

2. 单片机发展概述

1946 年第一台电子计算机诞生至今，只有50年的时间，依靠微电子技术和半导体技术的进步，从电子管——晶体管——集成电路——大规模集成电路，现在一块芯片上完全可以集成几百万甚至上千万只晶体管，使得计算机体积更小，功能更强。特别是近

20 年时间里，计算机技术获得飞速的发展，计算机在工农业，科研，教育，国防和航空航天领域获得了广泛的应用，计算机技术已经是一个国家现代科技水平的重要标志。

单片机诞生于20世纪70年代，像Fairchid公司研制的F8单片微型计算机。所谓单片机是利用大规模集成电路技术把中央处理单元(Center Processing Unit,也即常称的 CPU)和数据存储器(RAM)、程序存储器(ROM)及其他 I/O 通信口集成在一块芯片上，构成一个最小的计算机系统，而现代的单片机则加上了中断单元，定时单元及A/D 转换等更复杂、更完善的电路，使得单片机的功能越来越强大，应用更广泛。

20 世纪70 年代，微电子技术正处于发展阶段，集成电路属于中规模发展时期，各种新材料新工艺尚未成熟，单片机仍处在初级的发展阶段，元件集成规模还比较小，功能比较简单，一般均把CPU、RAM 有的还包括了一些简单的 I/O 口集成到芯片上，像Farichild 公司就属于这一类型，它还需配上外围的其他处理电路方才构成完整的计算系统。类似的单片机还有Zilog 公司的 Z80 微处理器。1976 年 INTEL 公司推出了MCS-48 单片机，这个时期的单片机才是真正的 8 位单片微型计算机，并推向市场。它以体积小，功能全，价格低赢得了广泛的应用，为单片机的发展奠定了基础，成为单片机发展史上重要的里程碑。在 MCS-48 的带领下，其后，各大半导体公司相继研制和发展了自己的单片机，像Zilog 公司的 Z8 系列。

到了80 年代初，单片机已发展到了高性能阶段像INTEL 公司的 MCS-51 系列，Motorola 公司的 6801 和 6802 系列，Rokwell 公司的 6501 及 6502 系列等等,此外,日本的著名电气公司 NEC 和 HITACHI 都相继开发了具有自己特色的专用单片机。80 年代，世界各大公司均竞相研制出品种多功能强的单片机，约有几十个系列，300 多个品种，此时的单片机均属于真正的单片化，大多集成了CPU、RAM、ROM、数目繁多的 I/O 接口、多种中断系统，甚至还有一些带 A/D 转换器的单片机，功能越来越强大，RAM 和ROM 的容量也越来越大，寻址空间甚至可达 64kB，可以说，单片机发展到了一个全新阶段，应用领域更广泛，许多家用电器均走向利用单片机控制的智能化发展道路。1982 年以后，16 位单片机问世，代表产品是 INTEL 公司的MCS-96 系列， 16 位单片机比起 8 位机，数据宽度增加了一倍，实时处理能力更强，主频更高，集成度达到了 12 万只晶体管，RAM 增加到了232 字节，ROM 则达到了8kB，并且有8 个中断源，同时配置了多路的 A/D 转换通道，高速的 I/O 处理单元，适用于更复杂的控制系统。

九十年代以后，单片机获得了飞速的发展，世界各大半导体公司相继开发了功能更为强大的单片机。美国 Microchip 公司发布了一种完全不兼容 MCS-51 的新一代 PIC 系列单片机，引起了业界的广泛关注，特别它的产品只有33条精简指令集,吸引了不少用户，使人们从INTEL的 111 条复杂指令集中走出来。PIC 单片机获得了快速的发展，在业界中占有一席之地。随后的事情，熟悉单片机的人士都比较清楚了，更多的单片机种蜂拥而至，MOTOROLA 公司相继发布了 MC68HC 系列单片机，日本的几个著名公司都研制出了性能更强的产品，但日本的单片机一般均用于专用系统控制，而不像INTEL 等

公司投放到市场形成通用单片机。例如NEC公司生产的uCOM87系列单片机，其代表作uPC7811 是一种性能相当优异的单片机。MOTOROLA 公司的 MC68HC05 系列其高速低价等特点赢得了不少用户。Zilog 公司的Z8 系列产品代表作是Z8671，内含BASIC Debug 解释程序，极大地方便用户。而美国过半的 COP800 系列单片机则采用先进的哈佛结构。ATMEL 公司则把单片机技术与先进的Flash存储技术完美地结合起来，发布了性能相当优秀的 AT89 系列单片机。包括中国的台湾HOLTEK和 WINBOND等公司也纷纷加入了单片机发展行列，凭着他们廉价的优势，分享一杯美羹。1990年美国INTEL公司推出了80960超级32位单片机引起了计算机界的轰动，产品相继投放市场，成为单片机发展史上又一个重要的里程碑。此期间，单片机园地里，单片机品种异彩纷呈，争奇斗艳。有8 位、16 位甚至 32 位机，但 8 位单片机仍以它的价格低廉、品种齐全、应用软件丰富、支持环境充分、开发方便等特点而占着主导地位。而INTEL公司凭着他们雄厚的技术，性能优秀的机型和良好的基础，目前仍是单片机的主流产品。只不过是九十年代中期，INTEL 公司忙着开发他们个人电脑微处理器，已没有足够的精力继续发展自己创导的单片机技术，而PHILIPS 等公司则继续发展C51系列单片机。

3.单片机的应用领域

单片机广泛应用于仪器仪表、家用电器、医用设备、航空航天、专用设备的智能化管理及过程控制等领域，大致可分如下几个范畴：

(1)在智能仪器仪表上的应用

单片机具有体积小、功耗低、控制功能强、扩展灵活、微型化和使用方便等优点，广泛应用于仪器仪表中，结合不同类型的传感器，可实现诸如电压、功率、频率、湿度、温度、流量、速度、厚度、角度、长度、硬度、元素、压力等物理量的测量。采用单片机控制使得仪器仪表数字化、智能化、微型化，且功能比起采用电子或数字电路更加强大。例如精密的测量设备（功率计，示波器，各种分析仪）。

(2)在工业控制中的应用

用单片机可以构成形式多样的控制系统、数据采集系统。例如工厂流水线的智能化管理，电梯智能化控制、各种报警系统，与计算机联网构成二级控制系统等。

(3)在家用电器中的应用

可以这样说，现在的家用电器基本上都采用了单片机控制，从电饭褒、洗衣机、电冰箱、空调机、彩电、其他音响视频器材、再到电子秤量设备，五花八门，无所不在。

(4)在计算机网络和通信领域中的应用

现代的单片机普遍具备通信接口，可以很方便地与计算机进行数据通信，为在计算机网络和通信设备间的应用提供了极好的物质条件，现在的通信设备基本上都实现了单片机智能控制，从手机、电话机、小型程控交换机、楼宇自动通信呼叫系统、列车无线通信、再到日常工作中随处可见的移动电话，集群移动通信，无线电对讲机等。

(5)单片机在医用设备领域中的应用

单片机在医用设备中的用途亦相当广泛，例如医用呼吸机，各种分析仪，监护仪，超声诊断设备及病床呼叫系统等等。此外，单片机在工商，金融，科研、教育，国防航空航天等领域都有着十分广泛的用途。

4.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)。像80C51就采用了HMOS(即高密度金属氧化阿物半导体工艺)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像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。