Sequential circuits are a class of digital circuits in which the output values depends not only on the input values but also on the past * state* of the circuit. This circuits utilize storage elements that store the values of logic signals.
There are two approaches when designing sequential circuits:
- Moore type
Circuits whose outputs depend only on the state of the circuit are called of Moore type - Mealy type
Circuits whose outputs depend on both the state and the primary inputs are called Mealy type
These circuits can be represented in a more abstract way by finite state machines.