control in the process industries.
基于微处理器的个人计算机被广泛用于加工工业中的直接数字控制。
implement“实现”之意。
2. The ADC conversion time constitutes the major part of the data sample acquisition time, but the S/H acquisition time must be considered also to establish maximum throughput.
ADC 转换时间是数据采集时间的主要组成部分，但也要考虑采样/保持时间，以便确定最大 的容许范围。
throughput“容许能力”之意。
3. The address decoder/command processor is used to latch data written to the DAS, which is then
converted to an appropriate analog signal by the DAC. 使用地址译码器或命令处理器将写到DAS 中的数据锁存起来，然后DAC 将这些数据转换成 适当的模拟信号。 句中的which 指data。
4.1 Introduction of DSP
1. This generates a digital output as a stream of binary numbers whose values represent the electrical
voltage input to the device at each sampling instant. 这个器件（AD 转换器）以二进制数码流的方式输出数据，这些二进制数码流的值表示了每 次采样时输入这个器件模拟电压的大小。
句中whose values represent the electrical voltage input to the device at each sampling instant 修饰 a stream of binary numbers。
2. Increasingly nowadays, the filtering of signals to improve signal quality or to extract important
information is done by DSP techniques rather than by analog electronics.
为了提高信号的品质或提取信号重要的信息而进行的信号滤波在现在更多地采用DSP 技术
来实现，而不是模拟电子技术，时至今日，这种趋势越来越明显。
句中to improve signal quality or to extract important information 修饰the filtering of signals。
3. However, general-purpose microprocessors such as the Intel x86 family are not ideally suited to
the numerically-intensive requirements of DSP, and during the 1980?s the increasing importance of
DSP led several major electronics manufacturers (such as Texas Instruments, Analog Devices and Motorola) to develop Digital Signal Processor chips-specialised microprocessors with
architectures designed specifically for the types of operations required in digital signal processing.
然而像Intel x86 系列这类通用处理器难以满足数字信号处理技术的高要求，在20 世纪80
年代，数字信号处理日益重要，这促使几个知名的电子产品制造商开发数字信号处理器芯片，
这些厂家包括德州仪器公司、模拟器件公司、摩托罗拉公司，数字信号处理芯片是一类专用
的微处理器，这类处理器具有数字信号处理所要求的特殊架构。
句中with architectures designed specifically for the types of operations required in digital signal processing 修饰specialised microprocessors。 4. DSP chips are capable of carrying out millions of floating point operations per second, and like
their better-known general-purpose cousins, faster and more powerful versions are continually being introduced.
DSP 芯片每秒钟能够执行数百万次的浮点运算，像众所周知的DSP 芯片一样，速度越来越快、性能越来越强的DSP 芯片被陆续推出。
5. DSP signal compression technology allows people not only to talk to one another but also to see
one another on their computer screens, using small video cameras mounted on the computer
monitors, with only a conventional telephone line linking them together.
有了数字信号压缩技术，人们不但可以在计算机显示器上安装一台小摄像机，而且可以通过一根普通的电话线传输声音和图像信号。
句中not only … but also …意为“不但??而且??”。6. Although some of the mathematical theory underlying DSP techniques, such as Fourier and Hilbert
Transforms, digital filter design and signal
compression, can be fairly complex, the numerical operations required actually to implement these techniques are very simple, consisting mainly of
operations that could be done on a cheap four-function calculator.
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尽管支持DSP 技术的数据理论，像Fourier 和Hilbert or written to.
变换、数字滤波器、信号压缩等理论
都很复杂，但实现这些理论的数学运算却是十分简单的，甚至于一些主要的算法可以用四功 能（加、减、乘、除）的计算器就能完成。 句中such as Fourier and Hilbert Transforms, digital filter design and signal compression 修饰DSP techniques。
7. The architecture of a DSP chip is designed to carry out such operations incredibly fast, processing hundreds of millions of samples every second, to provide real-time performance: that is, the ability to process a signal “live” as it is sampled and then output the processed signal, for example to a loudspeaker or video display.
数字信号处理器具有很快的运算速度，每秒能执行上亿次的采样，能够达到实时效果，也就
是说，它能够一边采样，一边处理实时信号，并将处理过的信号输出给扩音器或视频播放器 等设备。
4.2 Digital Signal Processors
1. Alphabetizing involved rearranging the order of the words until the ASCII values continually
increase from the beginning to the end of the list.
依照按字母顺序重新排列这些单词，直到ASCII 码值从头到尾依次递增排好。
2. Depending on the application, there may only be a few coefficients in the filter kernel, or many thousands.
根据应用的不同，滤波器的内核中可能有为数不多的几个系数，也有可能有好几千个系数。 3. Since the buses operate independently, program instructions and data can be fetched at the same
time, improving the speed over the single bus design. 由于总线是独立操作的，所以处理器可以同时读取程序指令和数据，这比起单总线设计的处理器在速度上有很大的提高。
4. Now let?s look inside the CPU. At the top of the diagram are two blocks labeled Data
Address Generator (DAG), one for each of the two memories. These control the addresses
sent to the program and data memories, specifying where the information is to be read from
现在让我们看看CPU 的内部，在图的顶部是两个标有DAG（数据地址生成器）的模块，分别对应两个存储器。这两个模块对应程序存储器和数据存储器输出地址，由它们指定读写的信息到底在哪儿。 句中specifying where the information is to be read from or written to 是条件状语从句修饰整个 句子。
5. In this mode, the DAGs are configured to generate bit-reversed addresses into the circular buffers, a necessary part of the FFT algorithm.
在这种模式中，DAG（数据地址生成器）被配置成为循环缓存器，用来产生位倒序地址，这
种寻址机构是FFT 算法中必不可少的一个部分。 6. The data register section of the CPU is used in the same way as in traditional microprocessors. In
the ADSP-2106x SHARC DSPs, there are 16 general purpose registers of 40 bits each. These can
hold intermediate calculations, prepare data for the math processor, serve as a buffer for data
transfer, hold flags for program control, and so on. CPU 的数据寄存器页面采用和传统微处理器相同的方式设计。在ADSP-2106x SHARC DSPs
中有16 个40 位的通用寄存器，这些寄存器用来保存计算的中间数据、存放数学运算的初始
数据、作为数据传递的缓冲器、保存程序控制的标志等。
7. For instance, an 80 bit accumulator is built into the multiplier to reduce the round-off error
associated with multiple fixed-point math operations. 例如，在乘法器中设计一个80 位的累加器，这样做是为了降低定点乘法运算中的溢出处理 程序的执行次数。
8. While the core and these peripheral sections are designed separately, they will be fabricated on the same piece of silicon, making the processor a single integrated circuit.
虽然内核电路和外设电路被独立设计，但它们能够被集成到同一个硅片上，这样，处理器就 是一块集成电路。
4.3 DSP Software
1. Although it looks meaningless to most humans, this pattern of ones and zeros contains all of the
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commands and data required to complete the task. 尽管对大多数人看起来它毫无意义，但这种0 和1 的模式蕴含了要完成任务的指令和数据。
2. Since working in binary will eventually drive even the most patient engineer crazy, these patterns of ones and zeros are assigned names according to the function functions, and expect you to derive the others.
许多高级语言提供为数不多的超越函数（高级函数），其他的函数还有待于你去解决。
4.4 DSP Application
1. There are approximately one billion telephones in they perform.
即使最有耐心的工程师，让他以二进制的方式编程也会使他发疯，因此根据功能不同对01 的产生方式做了命名。
3. Correspondingly, the compiler designates four bytes of memory that will be used for nothing but to hold the value of this variable.
相应地，编译器分配四个字节的存储空间，但这个存储空间专门用于保存这些变量的值。
句中that will be used for nothing but to hold the value of this variable 用来修饰数four bytes of memory。 4. This includes a wide range of engineers and
scientists who occasionally need DSP techniques to assist in their research or design activities.
这些人（业余程序员）包括很多工程师和科学家，为了解决科研或设计问题他们偶尔才会用到DSP 技术。
5. Programmers who like high-level languages (such as traditional computer scientists), will argue that
assembly is only 50% faster than compiled code, but five times more trouble.
喜欢高级语言的程序员（像传统的计算机学家）说，汇编代码比起编译代码快50％但却带 来了5 倍的麻烦。
句中who like high-level languages (such as traditional computer scientists) 修饰主语Programmers。
6. As a rule-of-thumb, expect that a subroutine written in assembly will be between 1.5 and 3.0 times faster than the comparable high-level program.
凭经验，人们认为一个用汇编语言写的程序往往比高级语言写的程序快1.5 到3 倍。
7. While computer hardware and programming languages are important for maximizing execution speed, they are not something you change on a day-to-day basis.
尽管计算机硬件和编程语言对优化系统的执行速度是至关重要的，但它们并不是一朝一夕就能改变的。8. Most languages only provide a few transcendental
the world. At the press of a few buttons, switching networks allow any one of these to be connected to any other in only a few seconds. 全世界大约有10 亿门电话，当我们按下几个电话键的时候，交换网络能够在瞬间把任意一 门电话和其他电话连通。
2. Digital Signal Processing attacks this type of problem by measuring the returned signal and generating an appropriate anti-signal to cancel the offending echo.
数字信号处理解决这类问题的方法是通过测量返回信号并产生一个对抗信号来削减令人讨厌的回声。 3. Digital data representation is important to prevent the degradation commonly associated with analog storage and manipulation.
用模拟形式存储和处理的音乐品质会下降，而用数字的形式去存储和处理音乐是解决这个问题的一种重要方法。
4. If the individual channels are simply added together, the resulting piece sounds frail and diluted, much as if the musicians were playing outdoors.
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如果将多个独立通道的声音被简单地叠加到一起，合成的声音听起来就会像在户外听音乐一样显得苍白无力。
5. An entire hour of recorded speech requires only about three megabytes of storage, well within the capabilities of even small computer systems.
整整一个小时的录音仅需要3 兆字节左右的存储量，对一般的小计算机来说这个存储量是微不足道的。
6. The characteristics of the resonate chamber are simulated by passing the excitation signal through a digital filter with similar resonances.
让激励信号通过一个具有类似共鸣特征的滤波器就可以模拟共鸣箱。
7. Each word in the incoming audio signal is isolated and then analyzed to identify the type of
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excitation and resonate frequencies.
接收到的声音信号被分割成单个的单词，然后分析这个信号以确定其激励和共鸣频率类型。
8. Aircraft in the path of this wave will reflect a small portion of the energy back toward a receiving antenna, situated near the transmission site.
接收天线就安装在紧邻发射元件的位置，位于雷达发射波范围的飞行器会反射小部分电磁波 到接收天线。
9. First, DSP can compress the pulse after it is received, providing better distance determination without reducing the operating range.
首先，在不缩小扫描范围的情况下，DSP 能够压缩脉冲提供更好的远距离特性。
10. Passive sonar typically uses lower frequencies than active sonar because they propagate through the water with less absorption.
因为低频的声音在水中传播时衰减要小，所以被动声纳比主动声纳使用更低频率。
11. By properly controlling and mixing the signals in these many elements, the sonar system can steer
the emitted pulse to the desired location and determine the direction that echoes are received from.
通过在这些部件中控制和混合信号，声纳系统能够朝着预定的方向发射这些脉冲信号，并确 定接收的回波从哪个方向来。
12. In spite of its obvious success, medical X-ray imaging was limited by four problems until DSP and related techniques came along in the 1970s.
尽管取得了一些成就，但仍然有至少四个问题制约了医用X 射线的使用，这些问题直到上世纪70 年代DSP 技术和一些相关技术的问世才得以解决。 13. Properly adjusting the strength and frequency of the fields cause the atomic nuclei in a localized region of the body to resonate between quantum energy states.
适当地调整磁场的频率和强度就会引起身体特定部位原子的共振，共振在原子能量级（能级）之间进行。
14. Adjustment of the magnetic field allows the
resonance region to be scanned throughout the body, mapping the internal structure.
电磁场的变化使得通过身体的共振区域能够被扫描并成像。
15. Just as with voice signals, images contain a
tremendous amount of redundant information, and can be run through algorithms that reduce the number of bits needed to represent them.
就像声音信号一样，图像里包含大量的冗余信息，这些图像经过算法处理可以降低其BIT 数(容量)。
5.1 The Intel MCS(R) 51 Single Chip Microcontroller Family
1. Depending only on the program memory contents, one chip could control a limitless variety of
products, ranging from appliances or automobile engines to text or data processing equipment.
依据程序存储器的内容不同，一个芯片能够实现多种产品，产品范围从应用电子产品、汽车 发动机、文字处理设备到数据处理设备。 2. and the 8022 put a unique two-channel 8-bit
analog-to-digital converter on the same NMOS chip as the computer, letting the chip interface directly with analog transducers.
8022 是在相同的NMOS 芯片上集成了一个独特的两通道8 位AD 转换器，这样8022 就可以直接和模拟变换器接口。
3. The primary difference between the three is the on-chip program memory of different types offered to satisfy differing user requirements.
三个芯片首要的不同就是片上存储器的类型不同，设计不同的片上存储器是为了满足不同用户的需求。
4. If software bugs are detected or design
specifications change the same part may be “erased” in a
matter of minutes by exposure to ultraviolet light and reprogrammed with the modified code.
如果发现了设计中的缺陷或设计要求有所更改，那么用紫外线只需照射几分钟芯片，对应部分的程序就可以被擦除，然后用修改好的代码重新编程。 5. For example, to represent positive and negative values, the most significant bit (D7) indicates the sign of
the other seven bits—0 if positive, 1 if
negative—allowing integer variables, between－128 and＋127.
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例如，为了表示正负数，最高位（D7）表示符号位，如果是0 表示正数； 1 表示负数，这样表示的数据范围从－128 到＋127 。
6. The program is stored inside the computer as a sequence of binary numbers, where each number corresponds to one of the basic operations (“opcodes”) 在有符号整数运算中，当算术溢出发生时溢出标志(OV)就会有效，这个功能使得2 的补码运算成为可能。
4. Data may be moved from any location on-chip to any register, address, or indirect address, any
register may be loaded with a constant, etc., all without which the CPU is capable of executing.
程序在计算机里用一系列二进制数进行存储，每个二进制数对应一个CPU 能够执行的基本操作（opcodes）。
7. The development system can mechanically translate the program from assembly language
“source” form to machine language“object” code using a program called an“assembler.”
开发系统使用一个叫做“汇编器”的程序能将汇编语言源程序转换成为机器语言即目标代码。
8. The machine language or instruction set is the set of operations which the CPU can perform while a program is executing (“at run-time”), and is strictly determined by the microcontroller hardware design. 机器语言或者称为机器指令是程序在运行时CPU 能够执行的一套操作，微控制器的硬件设计严格决定了这套指令的全部功能。
5. 2 Architecture and Organization
1. These primitive operations are automatically
cascaded and combined with dedicated logic to build complex instructions such as incrementing a sixteen-bit register pair.
简单的操作能够通过特定的逻辑自动重复和合并成为像16 位寄存器增量这类复杂的指令。
句中such as incrementing a sixteen-bit register pair 修饰complex instructions，to build complex instructions 作为目的状语。
2. While support for a more primitive data type may initially seem a step backwards in an era of increasing word length, it makes the 8051 especially well suited for controller-type applications.
在一个努力提高字长的时代，采用更为原始的数据类型乍看像是技术的退步，事实上这样做使得8051 更适合控制领域的应用。
3. The overflow flag (OV) detects when arithmetic overflow occurs on signed integer operands,making two?s complement arithmetic possible.
affecting the accumulator.
数据可以从片上存储器的任意位置移动到任意一个寄存器、地址或间接地址，任意一个寄存器也可以用常量装载，等等，所有这些操作都不影响累加器的值。
5. The high- and low-order halves of the data pointer may be manipulated as separate registers (DPH and DPL, respectively) or together using special instructions to load or increment all sixteen bits.
数据指针的高字节和低字节可以当作独立的寄存器（DPH，DPL）来对待，也可以当作联合的16 位用于一些特殊指令的加载或增量操作。
5.3 Special Peripheral Functions
1. The timer modes can be used to measure time intervals, determine pulse widths, or initiate events up to a maximum interval of 65536 instruction cycles (over 65 milliseconds).
定时器模式可以用来测量时间间隔、测量脉冲宽度或周期性地触发某一事件，事件触发时最大的周期为65 536 个指令周期。
2. Each microcontroller contains a high-speed, full-duplex, serial port which is software
programmable to function in four basic modes:
shift-register I/O expander, 8-bit UART, 9-bit UART, or inter-processor communications link.
每个微控制器具有一个高速、全双工的串行接口，这个接口可以通过软件编程决定它工作在四种模式中的一种，这四种模式分别是：移位寄存器I/O 扩展模式、8 位UART 模式、9 位UART 模式和多处理机通讯模式。
句中which is software programmable to function in four basic modes: shift-register I/O expander, 8-bit UART, 9-bit UART, or inter-processor communications link 修饰serial port。
3. When an event enabled for interrupts occurs the CPU automatically executes an internal subroutine call to the corresponding address.
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