Difference between Mealy machine and Moore machine
Mealy Machine is defined as a machine in the theory of computation whose output values are determined by both its current state and current inputs. In this machine at most one transition is possible.Â
It has 6 tuples: (Q, q0, ∑, â–², δ, λ’)Â
- Q is a finite set of statesÂ
- q0 is the initial stateÂ
- ∑ is the input alphabetÂ
- â–² is the output alphabetÂ
- δ is the transition function that maps Q×∑ → QÂ
- ‘λ’ is the output function that maps Q×∑→ â–²Â
Prerequisite – Mealy and Moore MachinesÂ
The diagram is as follows:
Moore Machine:
Moore’s machine is defined as a machine in the theory of computation whose output values are determined only by its current state. It has also 6 tuples
(Q, q0, ∑, â–², δ, λ)Â
- Q is a finite set of statesÂ
- q0 is the initial stateÂ
- ∑ is the input alphabetÂ
- â–² is the output alphabetÂ
- δ is the transition function that maps Q×∑ → QÂ
- λ is the output function that maps Q → â–²Â
Diagram:
The difference between the Mealy machine and Moore machine is as follows:
Moore Machine
|
Mealy MachineÂ
|
Output depends only upon the present state. |
Output depends on the present state as well as present input. |
Moore machine also places its output on the transition. |
Mealy Machine places its output on the transition. |
More states are required. |
Less number of states are required.  |
There is less hardware requirement for circuit implementation. |
There is more hardware requirement for circuit implementation.  |
They react slower to inputs(One clock cycle later). |
They react faster to inputs.  |
Synchronous output and state generation. |
Asynchronous output generation.  |
Output is placed on states. |
Output is placed on transitions.  |
Easy to design. |
It is difficult to design. |
If input changes, output does not change |
If input changes, output also changes. |
Has more or the same states as that of the Mealy machine. |
Has fewer or the same states as that of the Moore machine. |
Last Updated :
29 Jan, 2024
Like Article
Save Article
Share your thoughts in the comments
Please Login to comment...