Introduction to Digital Systems: Modeling, Synthesis, and Simulation Using VHDL

1.2 MODELING, SYNTHESIS, AND SIMULATION DESIGN

Modeling and simulation have their roots in digital systems. Long before they became the basis of an interdisciplinary field, modeling and simulation were used extensively in digital system design. As electronic and computer technology advanced, so did modeling and simulation concepts. Today, the many computer-aided design (CAD) tools are pushing the limit of modeling, synthesis, and simulation technology. We focus on the implementation of modeling, synthesis, and simulation in digital systems.

A digital system is a system that takes digital signals as inputs, processes them, and produces digital output signals. A digital signal is a signal in which discrete steps are used to represent information and change values only at discrete (fixed) time intervals. In contrast, analog signals have “continuous” variations in signal amplitude over time. At a given instant of time, an analog signal has infinite possible values. A digital signal has discrete amplitude and time. Digital systems are very useful in the areas of signal processing (i.e., audio, images, speech, etc.), computing, communication, and data storage, among others. Digital systems are so commonplace in today's world that we tend to miss seeing them. Almost all electronic systems are partially or totally digitally based. Of course, real-world signals are all analog, and interfacing to the outside world requires conversion of a signal (information) from digital to analog. However, ...