Synchronized and Asynchronous Finite State Machines A synchronous finite state machine (SFSM) is a type of finite state machine (FSM) in which the states...
A synchronous finite state machine (SFSM) is a type of finite state machine (FSM) in which the states are synchronized by an external signal. This means that the state transitions occur only when the external signal reaches a certain level or threshold.
Example:
Imagine a machine that controls a motor. The machine has three states: On, Off, and Error. The machine transitions between these states when the external signal detects a switch being pressed or released. The machine stops transitioning when the external signal is inactive.
An asynchronous FSM is similar to an SM, but the state transitions can occur independently of the external signal. This means that the state transitions can happen at any time, not just when the external signal reaches a certain level.
Example:
Consider a machine that performs a complex mathematical calculation. The machine could be in several different states, such as Divide by 2, Multiply by 3, or Add 10. Each of these states could be reached independently, without any external signal triggering the transition.
Key differences between SSFMs and ASFMs:
| Feature | Synchronous FSM | Asynchronous FSM |
|---|---|---|
| State transitions | Synchronous by external signal | Independent |
| State transitions | When the external signal reaches a certain level | At any time |
| Use case | Machines that require precise synchronization between states | Machines that need to perform complex calculations independently |
Benefits of SSFMs:
More robust to noise and external disturbances
Can handle more complex and realistic systems
Benefits of ASFMs:
More efficient for certain types of computations
Can be implemented using simpler circuitry
Additional points:
Both SSFMs and ASFMs can be combined to achieve more complex behaviors.
The choice between an SSFM and an A-SM depends on the specific requirements of the system