Motorola DSP56000 manual Introduction, Origin of Digital Signal Processing

INTRODUCTION

1.1INTRODUCTION

The DSP56K Family is Motorola’s series of 24-bit general purpose Digital Signal Proces- sors (DSPs*). The family architecture features a central processing module that is common to the various family members, such as the DSP56002 and the DSP56004.

Note: The DSP56000 and the DSP56001 are not based on the central processing module architecture and should not be used with this manual. They will continue to be described in the DSP56000/DSP56001 User’s Manual (DSP56000UM/AD Rev. 2).

This manual describes the DSP56K Family’s central processor and instruction set. It is intended to be used with a family member’s User’s Manual, such as the DSP56002 User’s Manual.

The User’s Manual presents the device’s specifics, including pin descriptions, operating modes, and peripherals. Packaging and timing information can be found in the device’s Technical Data Sheet.

This chapter introduces general DSP theory and discusses the features and benefits of the Motorola DSP56K family of 24-bit processors. It also presents a brief description of each of the sections of the manual.

1.2ORIGIN OF DIGITAL SIGNAL PROCESSING

DSP is the arithmetic processing of real-time signals sampled at regular intervals and dig- itized. Examples of DSP processing include the following:

•Filtering of signals

•Convolution, which is the mixing of two signals

•Correlation, which is a comparison of two signals

•Rectification, amplification, and/or transformation of a signal

All of these functions have traditionally been performed using analog circuits. Only recent- ly has semiconductor technology provided the processing power necessary to digitally perform these and other functions using DSPs.

Figure 1-1shows a description of analog signal processing. The circuit in the illustration filters a signal from a sensor using an operational amplifier, and controls an actuator with the result. Since the ideal filter is impossible to design, the engineer must design the filter for acceptable response, considering variations in temperature, component aging, power supply variation, and component accuracy. The resulting circuit typically has low noise im- munity, requires adjustments, and is difficult to modify.

*This manual uses the acronym DSP for Digital Signal Processing or Digital Signal Processor, de- pending on the context.

MOTOROLA DSP56K FAMILY INTRODUCTION 1 - 3