ABSTRACT
This chapter presents system design approaches based on packages, components, functions and procedures. Advantages of digital system design using these standard approaches are explained, and their significance is highlighted with the design examples, such as a signal generator, seven-segment display, half/full adder/subtractor, N-bit signed magnitude comparator, digital clock design, up/down counter design, PWM signal generation and so on. Digital system design to get the final correct sum/differences in both signed and unsigned addition/subtraction is presented, with digital architecture and function tables. Design approaches for signed/unsigned magnitude comparators using basic gates are detailed. Different configurations of seven-segment display units and their wiring with FPGA, either directly or through a decoder IC, are explained, with sketch and circuit diagrams. Different configurations of digital counter design and their working principles are explained, with design examples. The design of a digital real-time clock with an indication of AM/PM is presented. The significance of the PWM signal and methodology of using it to control the speed of a DC motor is explained. Some advanced techniques of modelling digital systems using packages, libraries, functions and procedures are also given, with appropriate design examples.
