文献翻译单片机系统

重 庆 理 工 大 学文 献 翻 译二级学院 电子信息与自动化 班 级 测控技术与仪器3班 学生姓名 余泓霖 学 号 10807030331 单片机系统1.单片机单片机即单片微型计算机，是把中央处理器、存储器、定时/计数器、输入输出接口都集成在一块集成电路芯片上的微型计算机。与应用在个人电脑中的通用型微处理器相比，它更强调自供应（不用外接硬件）和节约成本。它的最大优点是体积小，可放在仪表内部，但存储量小，输入输出接口简单，功能较低。由于其发展非常迅速，旧的单片机的定义已不能满足，所以在很多应用场合被称为范围更广的微控制器，但是目前在中国大陆仍多沿用“单片机”的称呼。 绝大多数现在的单片机都是基于冯诺伊曼结构的，这种结构清楚地定义了嵌入式系统所必需的四个基本部分：一个中央处理器核心，程序存储器（只读存储器或者闪存）、数据存储器（随机存储器），一个或者更多的定时/计时器，还有用来与外围设备以及扩展资源进行通信的输入/输出端口所有这些都被集成在单个集成电路芯片上。说单片机与通用型中央处理单元芯片不同是因为前者一般很容易配合最小型的外部支持芯片制成工作计算机。这样就可以很容易的把单片机系统植入装置内部来控制装置了。近年来为了在指令和数据上使用不同的字宽，并提高处理器流水线速度，哈佛结构在微控制器和DSP也逐渐得到了广泛的应用。 传统的微处理器是不允许这么做的。它要完成单片机的工作，就必须连接一些其他芯片。比如说，片上没有数据存储器，就必须要添加一些RAM的存储芯片，虽然所添加存储器的容量很灵活，但是至少还是要添加，另外还需要添加很多连线来传递芯片之间的数据。 比如，一个典型的微控制器只需要一个时钟发生器和很少的RAM和ROM(或者EPROM, E2PROM)就可以在软件和晶振下工作了。同时，微控制器具有丰富的输入输出设备，像是模拟数字转换(ADC)，定时器，串口或者其他串行通讯接口(比如I2C，串行外围接口(SPI),控制器局域网)。通常，这些继承在内部的设备可以通过特殊的指令来操作。一些现代的微控制器支持一些内建的高级编程语言，比如BASIC语言。一个微控制器（也叫MCU）是一个微型计算芯片。它包含一个处理器、一个内存（有少量的RAM ，程序存储器，或两者兼而有之）和一个可编程输入/输出外设。 它强调高度集成，而相比之下，一个微处理器只包含一个CPU （比如一台PC ） 。除了通常的算术和逻辑要素等一般用途的微处理器，微控制器还集成了更多的要素，如读写存储器的数据存储，只读存储器的存储程序，快闪记忆体的永久数据存储，外设，和输入/输出接口。在时钟频率只有32Mhz的情况下 ，微操作系统往往以非常低的速度相运行，但是这足够典型的应用。他们消耗较少的功率（毫瓦或什微） ，且具有保持功能，同时可以等待一个事件，如一个按钮的按下或中断。在睡眠状态时， CPU时钟和外设禁用，从而使它们适合用于低功耗和长期持久的电池应用。 微控制器广泛应用于自动控制产品和设备，如汽车发动机控制系统，远程控制系统，办公室机器设备系统，家用电器，电动工具，和玩具等。通过降低尺寸，成本和能耗，设计使用单独的微处理器，内存和输入/输出设备，能够使微控制器控制更多的进程，更经济。目前，大多数的计算机系统被嵌入在其他设备中使用，如汽车，电话以及很多需要外设的计算机系统。这些嵌入其他设备的计算机系统被称为嵌入式系统。有些嵌入式系统是非常复杂的，很多能够达到人们的要求，但由于内存和程序长度的限制，软件的复杂性降低。典型的输入和输出设备包括交换机，继电器，螺线管，发光二极管，小形或定制的液晶显示器，数码显示器等。射频设备和传感器等嵌入式系统通常没有键盘，屏幕，硬盘，打印机或其他公认的I / O设备，并可能缺乏人机互动装置的任何一种。某些强制性的微控制器能够提供实时应对突发事件的嵌入式系统并控制它们。当某些事件发生时，中断系统能够让信号处理器暂停处理当前的指令序列，并开始了中断服务。当中断服务结束之后，再返回原来的指令序列，这就是我们通常所说的单片机的中断系统。中断源的设备依赖通常有很多种，如内部定时器溢、完成了模拟向数字转换、逻辑水平变化的一种投入、一个按钮被按下和收到了数据的通信联系等。凡是许多重要的中断源发出中断申请，都必须中断，如电池供电的设备停止运行后，微控制器在低功耗睡眠状态下的处理器必须停止，直到做一些外围的活动才重新开始返回当前指令序列。单片机程序必须符合现有的芯片程序存储器的要求，因为这将是代价高昂的系统提供了与外部设备之间可以扩展的存储器。编译器和汇编语言是用来打开高级语言程序到一个紧凑机器代码存储在微控制器的存储过程。根据不同的设备，程式记忆体可能是永久性的，而唯读存储器，只能进行编程。在工厂，可以生产可擦除式只读存储器。由于嵌入式处理器通常是用来控制设备的，他们有时需要接受输入设备的数据输入，但由于处理器内置处理数数据只有1和0 ，所以它们将无法直接处理任何模拟信号。因此，要先使需要处理的数据通过模拟向数字转换的过程，才能使传入的数据转化为处理器可以识别的形式。还有一种转换器叫做数模转换器，他能够使数字信号转换为模拟信号并将数据发送到需要CPU控制的设备上，以达到控制的目的。此外，许多嵌入式微处理器包括各种兼职的转换器。最常见的一种类型的转换器是可编程间隔定时转换器。工作过程为一个倒计时刚到达零，它就会对处理器发出一个中断的指令。这表明它已经完成转换，并需要对所控制的设备发出指令，使其作出某些动作。这是非常有用的设备，如恒温系统，需要定期测试他们周围的温度，看看他们是否需要打开空调或者加热器等等。 英文原文：Single chip microcomputer system1.MCUMCU single-chip microcomputer, central processing unit, memory, timer / counters, input and output interfaces are integrated on an integrated circuit chip microcomputer.And application of general-purpose microprocessor in the PC, it is more emphasis on self-supply (no external hardware) and cost savings. Its biggest advantage is small size, can be placed inside the instrument, but a small amount of memory, input and output interface is simple, with weaker. Very quickly due to its development, the old definition of SCM can not meet, known as a wider range of microcontrollers in many applications, but in mainland China is still to follow the call of the SCM.The vast majority present microcontrollers are based on the Von Neumann structure, this structure clearly defines the four basic parts necessary for embedded systems: a central processor core, program memory (read-only memory or flash memory)data memory (RAM), one or more timer / timer, used to communicate with peripherals and expansion of resources to communicate with input / output ports - all of which are integrated in a single integrated circuit chip. Said microcontroller and general-purpose central processing unit chip is because the former are generally very easy with the smallest external support chips to work computer. This can be easily single-chip system within the implanted device to control the device. In recent years, in order to use different instruction and data word width, and increase the speed of the processor pipeline, Harvard architecture microcontrollers and DSP gradually get a wide range of applications.Conventional microprocessor is not allowed to do so. It is to complete the work of the microcontroller must be connected to other chips. For example, the on-chip data memory, it is necessary to add some RAM memory chips, although the added memory capacity is very flexible, but at least has to be added, also need to add a lot of connections to pass data between chips. For example, a typical micro-controller requires only a clock generator and a small RAM and ROM (or EPROM, the E2PROM) can work in the software and crystal. At the same time, the microcontroller has a wealth of input and output devices, such as analog to digital converter (ADC), timers, serial port or other serial communication interface (such as I2C, serial peripheral interface (SPI), controller area network). Typically, these inherited by special instructions in the internal device to operate.Some modern microcontrollers support a number of built-in high-level programming language such as BASIC language.A microcontroller (also known as MCU) is a micro-computer chips. It contains a processor, a memory (a small amount of RAM, program memory, or both) and a programmable input / output peripherals.It emphasizes a high degree of integration, in contrast to a microprocessor that contains only one CPU (such as a PC). In addition to the usual arithmetic and logic elements of general-purpose microprocessors, microcontrollers also integrates additional elements, such as read-write memory for data storage, read-only memory storage process, the flash memory for permanent data storage, peripherals, and input / output interface. Only 32Mhz clock frequency, micro-operating system is often running at very low speed, but this is enough to typical applications. They consume less power (milliwatts or even micro), and has a hold function, while waiting for an event, such as a button press or interrupt. In sleep mode, the CPU clock and peripheral disabled, making them ideal for low power consumption and long-lasting battery applications.Microcontrollers are widely used in automatic control products and equipment, such as automobile engine control systems, remote control systems, office machines and equipment, household appliances, electric tools, and toys and so on. By reducing the size, cost and power consumption, designed to use a separate microprocessor, memory and input / output device, enables the microcontroller to control the more the process more economical.At present, most computer systems are embedded in other equipment in use, such as cars, phones, and peripherals computer systems. These computer systems embedded in other devices are called embedded systems. Some embedded systems are very complex, many can achieve the requirements of people, but because of the limitations of memory and program length, reduces the complexity of the software. The typical input and output devices, including switches, relays, solenoids, LEDs, small shape or custom LCD display, digital display. RF devices and sensors, embedded systems often do not have a keyboard, screen, hard disk, printer, or other recognized I / O devices, and may lack any kind of human-computer interactive device.Some mandatory micro-controller to provide real-time embedded systems to respond to emergencies and to control them. When certain events occur, the interrupt system allows the signal processor to suspend the processing of the current sequence of instructions, and start the interrupt service. After the end of the interrupt service, and then return to the original sequence of instructions, which we usually refer to the microcontroller interrupt system. Interrupt source device dependency is usually there are many, such as internal timer overflow, complete analog to digital conversion, an input of the logic level changes, a button is pressed, and receive data communication links. All important interrupt sources issued the interrupt request, must be interrupted, such as battery-powered devices to stop the run, the microcontroller in the low-power sleep state, the processor must stop, start again return until you do some peripheral activities the current instruction sequence.SCM program must meet the requirements of the existing chip program memory, as it will be costly system memory can be extended with external devices. Compiler and assembly language is used to open a high-level language program into a compact storage of the machine code is stored in the microcontroller. Depending on the device, the program memory may be permanent, read-only memory, can only be programmed. Type in the factory, can produce erasable read-only memory.Embedded processor is usually used to control equipment, they sometimes need to accept the input device data input processor built-in address a number of data is only 1 and 0, so they will not be able to deal directly with any analog signal. Therefore, the data need to be addressed first in or