hi its practice question.the question is "what state this circuit will never go into?".the variable x is just a switch that when 0 makes the sequential circuit follow the upper state digram and when 1 the lower state digram.D flip flops are used

 

Can you post the schematic and state table as a .PNG or .PDF attachment?

 

is it viewable now?

 

learn kanaugh mapping that the question you will answer it.

 

Well, if your state diagrams are correct, it should be obvious which state(s) the circuit will never transition into...

 

The following process will help you approach the answer:

Draw all 8 states in one image and connect them using your 2 images with arrows. Note 1 above the arrows that refer to the upper image and 0 over the ones that came from the lower.

The states that have only outcoming and no incoming arrows are ureachable from the other states.