ABSTRACT
This chapter introduces the principles of combinational logic design at the gate level. It defines logic levels and deals with the design and optimization of combinational logic functions that can be built out of discrete gates. The chapter also deals with cellular logic, where design principles are required to produce an individual cell, which can then be repeated, using integrated circuit methods, to produce complex devices. A cellular structure is ideally suited to integrated circuit manufacturing techniques. In order to design a combinational circuit the inputs and their corresponding outputs must be identified. A combinational system having more than one output can be considered as several single-output logic circuits operating on common inputs. Once the input/output relationship has been defined, a truth table can be calculated. In some logic systems, 'don't care' conditions can be identified on the outputs. Electronic logic circuits are imperfect devices.
