DSP原理与应用双语1.ppt

Dr. Naim Dahnoun, Bristol University, (c) Texas Instruments 2004 Chapter 1 Introduction Learning Objectives Why process signals digitally? Definition of a real-time application. Why use Digital Signal Processing processors? What are the typical DSP algorithms? Parameters to consider when choosing a DSP processor. Programmable vs ASIC DSP. Texas Instruments’ TMS320 family. Why go digital? Digital signal processing techniques are now so powerful that sometimes it is extremely difficult, if not impossible, for analogue signal processing to achieve similar performance. Examples: FIR filter with linear phase. Adaptive filters. Why go digital? Analogue signal processing is achieved by using analogue components such as: Resistors. Capacitors. Inductors. The inherent tolerances associated with these components, temperature, voltage changes and mechanical vibrations can dramatically affect the effectiveness of the analogue circuitry. Why go digital? With DSP it is easy to: Change applications. Correct applications. Update applications. Additionally DSP reduces: Noise susceptibility. Chip count. Development time. Cost. Power consumption. Why NOT go digital? High frequency signals cannot be processed digitally because of two reasons: Analog to Digital Converters, ADC cannot work fast enough. The application can be too complex to be performed in real-time. Real-time processing DSP processors have to perform tasks in real-time, so how do we define real-time? The definition of real-time depends on the application. Example: a 100-tap FIR filter is performed in real-time if the DSP can perform and complete the following operation between two samples: Real-time processing We can say that we have a real-time application if: Waiting Time ? 0 Why do we need DSP processors? Why not use a General Purpose Processor (GPP) such as a Pentium instead of a DSP processor? What is the power consumption of a Pentium and a DSP processor? What is the cost of a Pentium and a DSP processor? Why