COMBINATIONAL VS SEQUENTIAL LOGIC SOFTWARE

* I could go into Mealy and Moore FSMs, where the output is a function of I and S or just of S, but they are (a) already written up well on the internet and (b) not the goal of the question. They can also argue that 1=2 but to no useful end in electronics engineering. Beyond that, you might bump into some less scientific and frankly whimsical notions of the circuits or terms described. There is a whole wider science of theory and analysis on FSMs themselves and for other applications. Note that this answer confines itself to practical electronics design engineering. So it is of no practical value to do so and could only produce confusion if done.

COMBINATIONAL VS SEQUENTIAL LOGIC SOFTWARE

But you will find little example of this in the vast array of digital electronics components, programmable logic components, circuitry and support software tools on the market.

The digital logic term 'state' could be hijacked away from its satisfactory use in FSMs to mean 'output'. The term 'state' does mean other things in wider electronics. No more than the output of an oscillator is an output waveform, not its state. Note that the combinatorial circuit outputs are outputs - they are not a 'state'. The memory component has a specific capacity measured in. Therefore a combinatorial logic circuit would be used. The main difference between a combinational and a sequential logic circuit is that the former contains only logic gates, whilst the latter contains both. Circuits that include both combinational logic and memory components are called sequential logic. The state is stored in the memory circuit and gives the FSM the functions of sequence and elapsed time that the combinatorial logic does not have.Īn FSM machine that was indistinguishable from a combinatorial logic circuit by the behaviour of its inputs and consequent outputs would not contain any state activity and therefore need no state memory. The outputs depend upon the state and the state depends on what the inputs have previously done. It produces outputs O and a new state N that are a logic function of its current state S and its inputs I.Įach combination of FSM inputs does not produce a fixed output combination. Each combination of inputs produces a fixed output combination.Ī Finite State Machine (FSM)* contains combinatorial logic and also state memory. No, a combinatorial digital logic circuit is not a digital logic state machine, by any definition.Ī combinatorial digital logic circuit contains no memory elements and responds immediately to changes in its inputs to produce its outputs.

Is combinational logic a Finite State Machine?' This is in contrast to Finite State Machines (FSM) which have memory and state. 'Combinational logic is a stateless computational model.The OP has changed their actual question five times.

Combinational vs sequential logic