Pattern recognizer Design a pattern recognizer with a single

Pattern recognizer:

Design a pattern recognizer with a single input x and a single output y that outputs a logic 1 when a pattern \"1001\" is observed, and otherwise outputs a zero.

When x(t-3,t-2,t-1,t) = \"1001\" then y(t) = 1 else y(t) = 0

Here is the question:

Write the state transition table and excitation table for D flip-flops using a state encoding of your choice.

Solution

state transistion table

D Q Qn+1

1 1 1

0 0 0

iN D FLIP if input is 0, output will also be 0

and same for 1

excitation table

Q = 1 D=1

Q=0 D=0