# sequential synchronous circuit

I'm learning about sequential synchronous circuits, and I was trying to do an exercise, but I'm not going as I expected.

• Elaborate the excitation equation of flip-flops;
• Write the output equation;
• Say if it is a Moore or Mealy Machine;
• Elaborate transition table and outputs;
• Draw the state diagram;

So, my biggest problem is the first question "Elaborate the excitation equation of flip-flops", once I done the first question I think I can handle this exercise Something is getting confusing in my head.

1 - Should I consider "A-B-C" as inputs or outputs? Taking into account a Mealy machine the Output is a function of current state and inputs, if I consider "A-B-C" as my inputs what would be my output for example?

2 - I tried excitation equation of each flip-flop (considering "A-B-C" as inputs)

Q0 = B


Q1 = C


And

Q3 = (C'+ B')  ^ ( B ^ A )             -> " ^ = Xor "


As you can see i'm a little confused, if sameone can help me I would be grateful. Thanks everyone!

• Why do you think they are inputs? Imagine Qo is driving '0', and you drive A to '1'. What will happen? Commented Jun 1, 2021 at 18:37
• On a D flip-flop, D is the input and Q is the output. On any flip-flop, Q is the output. Commented Jun 1, 2021 at 21:48