ABSTRACT
This chapter describes some of the basic building blocks of sequential logic, and to introduce the general sequential machine as a design technique for any synchronous circuit. It also describes the most basic circuit elements that have the property of memory. The chapter shows how these elements can form the basis of practical devices. Finally it introduces a systematic design approach to sequential circuitry. The basic property of a memory device is that it should be able to hold its output at a fixed value until instructed to change it. For logical elements this output value should either be a 0 or a 1. This function is provided by bistable logic circuits which have two stable states, a set state and a reset or clear state. A great many integrated circuit shift registers are available with various combinations of serial or parallel loading, serial or parallel output, and left or right shift.
