9: Finite-State Automata
- Page ID
- 50491
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Learning Objectives
Upon successful completion of this unit, you will be able to:
- illustrate abstract machines that can be in exactly one of a finite number of states at any given time;
- analyze systems that recognize input patterns, accepting or rejecting an input depending on whether a given pattern occurs;
- construct discrete-state systems; and
- predict how a given system will enter different states as new data is input to the system over time.
A finite-state machine (FSM) is a mathematical model of computation that describes an abstract machine in one of a finite number of states at any point in time. The FSM can change from one state to another as it responds to data inputs, or when some condition is satisfied. The change from one state to another is called a transition. An FSM is defined by a list of its states, its initial state, and the conditions for each transition. Often, state machines are illustrated as graphs whose nodes are the states and whose links are the transition conditions.
Completing this unit should take you approximately 2 hours.
- 9.2: State Transition Diagrams
- How we illustrate a finite-state machine has a great deal to do with how well others will understand our design. There is also an opportunity for objective review and evolution of the underlying system. This video continues with a discussion on the design of a combination lock.
- 9.4: Putting the Basics to Use
- Watch these videos for examples of using FSMs in the real world. They also discuss some subtle issues related to implementing FSMs.