Abstract
The circuits considered so far have been combinational, that is, circuits in which the steady-state output is a function of the present inputs only. However, in most practical systems we must consider another, more general, type of circuit, where the output is a function of both present and past inputs. These circuits, called sequential circuits (also known as state machines or finite-state machines) are contained in most digital systems as counters, registers, memories, etc. A familiar example of sequential behaviour is provided by the telephone system, where a call must be made by entering the correct numbers in the correct sequence. A sequential circuit is modelled as a combinational circuit with the additional properties of memory or storage (to ‘remember’ previous inputs) and feedback so that previous inputs can affect future outputs. A general diagram representing a sequential circuit is shown in Fig. 6.1.
Keywords
State Diagram Truth Table State Table Linear Feedback Shift Register Clock PulsePreview
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