The logic circuits discussed in Digital Electronics Module 4 had output states that depended on the particular combination of logic states at the input connections to the circuit. For this reason these circuits are called combinational logic circuits.
Use Module 5 to learn about digital circuits that use SEQUENTIAL LOGIC.
In these circuits the output depends, not only on the combination of logic states at its inputs, but also on the logic states that existed previously. In other words the output depends on a SEQUENCE of events occurring at the circuit inputs. Examples of such circuits include clocks, flip-flops, bi-stables, counters, memories, and registers. The actions of these circuits depend on a range of basic sub-circuits.