A sequential circuit with three D-type flip-flops Y1Y2Y3, input X and output Z is defined with the following input/output functions:
D 1 = X Y 3 + X Y 1 Y 3 D 2 = X ( Y 3 + Y 2 ) + X Y 2 Y 3 D 3 = X Y 3 + Y 2 Y 3 Z = Y3
(a) Find the state table for the circuit and replace the state codes with single letter state identifiers. Note that, states 100 and 111 were unused in the design.
(b) Check for, identify and combine equivalent states.