I'm trying to design the counter shown in the diagram below with the counting sequence 123456 (i.e X1=1, X2=2, ...) as a Mealy machine. State diagram

However, I'm having trouble figuring out how to create the state transition table for the machine. For context, I designed this counter as a Moore machine using 3 D flip flops, and I implemented it on a FPGA board. When I push a button on the board (Rb), the number is displayed. I guess what I'm struggling with is how the table for the Mealy machine would differ from that of the Moore machine. For example, the first two rows of my Moore table look like this: State transition table

How does the input affect the output any differently than the Moore machine? (Apologies for the long question)


1 Answer 1


If your count sequence is 12345612...

Wouldn't your Moore Machine be:

Moore Machine

And Mealy Machine be:

Moore Machine

Moore Machine output is a function of Present State only. Moore changes on clock cycle, synchronous.

Mealy Machine output is a function of Input Rb and Present State. Outputs can change if inputs change, asynchronous.

  • \$\begingroup\$ What software did you use to make the state diagrams? \$\endgroup\$
    – Carl
    Jul 26, 2021 at 18:33
  • 1
    \$\begingroup\$ @Carl The software was Dia. \$\endgroup\$ Jul 26, 2021 at 18:34

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