7/22/2019 Capabilities and Limitations of FSM

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1. What do you mean by finite state machine?

Finite state machine can be defined as a type of machine whose past

histories can affect its future behavior in a finite number of ways. To clarify, consider

for example of binary full adder. Its output depends on the present input and the

carry generated from the previous input. It may have a large number of previousinput histories but they can be divided into two types !i" Input combination that

produces carry# !ii" Input combination that produces no carry. Implying the past

histories can affect the future behavior in a finite number of ways !here $".

$. What are the capabilities and limitations of finite%state machine?

&et a finite state machine have n states. &et a long se'uence of input

be given to the machine. The machine will progress starting from its beginning state

to the next states according to the state transitions. (owever, after some time the

input string may be longer than n, the number of states. )s there are only n states

in the machine, it must come to a state it was previously been in and from thisphase if the input remains the same the machine will function in a periodically

repeating fashion. From here a conclusion that *for a n state machine the output will

become periodic after a number of cloc+ pulses less than e'ual to n can be drawn.

tates are memory elements. )s for a finite state machine the number of states is

finite, so finite number of memory elements are re'uired to design a finite state

machine.

&imitations

!a" -o finite state machine can be produced for an infinite se'uence.

!b" -o finite state machine can multiply two arbitrary large binary numbers.