ABSTRACT

Each hardware component of a computer system is built of several logic circuits. A logic circuit is an interconnection of several primitive logic devices to perform a desired function. It has one or more inputs and one or more outputs. This chapter introduces some logic devices that are used in building one type of logic circuit called a combinational circuit. Each output of a combinational circuit is a function of all the inputs to the circuit. Further, the outputs at any time are each a function of inputs at that particular time, and so the circuit does not have a memory. A circuit with a memory is called a sequential circuit. The output of a sequential circuit at any time is a function of not only the inputs at the time but also the state of the circuit at that time. The state of the circuit is dependent on what has happened to the circuit prior to that time, and hence the state is also a function of previous inputs and states. This chapter is an introduction to the analysis and design of combinational circuits. Details of sequential circuit analysis and design are given in Chapter 4.