Lesson 17 Digital signal processors.pptVIP

《电子信息工程专业英语教程》 Lesson 17 Digital signal processors 《电子信息工程专业英语教程》任治刚 主编 电子工业出版社 Lesson 17 Digital signal processors Terminology Von Neumann architecture 冯·诺依曼结构 Harvard architecture 哈佛结构 Multiplier 乘法器 Accumulator 累加器 Shifter 移位器 address generator 地址产生器 circular buffer　循环缓冲区 Terminology Fixed point　定点 Floating point 浮点 Mantissa 尾数 Exponent 指数 parallel architecture　并行结构 looping scheme　循环机制 third party developer　第三方开发商 licensing agreement　专利使用权转让协定 Digital signal processing tasks can be performed by all processors. Specialized digital signal processors (DSPs), however, perform these tasks most efficiently and most quickly. the Harvard or modified Harvard architecture multiple memories and buses fast multipliers, accumulators, and shifters hardware support for circular buffers Address generators DSPs are available in two major classes: fixed point floating point The dynamic range 16-bit fixed point: 96.3 dB 32-bit float point( 24 bits for the mantissa and 8 bits for the signed exponent): 1535.3 dB Choosing a DSP for a particular application is not always easy. The first decision is on whether to choose a fixed point or a floating point device fixed point devices are cheaper and quicker floating point devices are more convenient to program and more suited to calculation-intensive algorithms The data width of the DSP determines how accurately it can represent numbers. Speed is another issue, not only how many cycles occur in each second, but also how many instructions execute in each cycle and how much work each of these instructions accomplishes. The specific hardware and software features offered by a particular DSP can make one choice better than another, as can the amount of on-chip memory available DSPs can be purchased in three forms as a core as a processor as a board level product. the distinction between DSPs and other microprocessors is not always a clear line. it is very possible that the Digital Signal Processor may be