Hardware Design Interview Question:

How to detect sequence of "1101" arriving serially from signal line?

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Sequence detector : A sequence detector gives an output of 1 on detecting the given sequence else the output is zero.

Ex : if the given sequence to be detected is 111
and input stream is 1 1 0 1 1 1 0 0 1 0 1 1 1 1 1
the output should be 0 0 0 0 0 1 0 0 0 0 0 0 1 1 1.

Soln:
One of the different possible ways to detect a sequence is using a Mealy type FSM.

Using the following table the State machine can be designed.
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