if a finite state machine has 5 input signals

A, B, C, D, E

Does this mean there must be 2⁵ inputs along with the state built into the logic?

  • \$\begingroup\$ 32 POSSIBLE & BINARY input states exist. All may not be used. \$\endgroup\$
    – Russell McMahon
    May 8, 2019 at 9:31

1 Answer 1


Yes, there are 32 possible input combinations for each state. But in some states, some of the inputs might be "don't cares", so you won't have to write out all the combinations explicitly, whether you're making a state transition table, a state diagram, or writing HDL code to define the state machine.

  • \$\begingroup\$ i think that you may have meant to say No, there are 32 possible input combinations for each state, but in some states, ....... \$\endgroup\$
    – jsotola
    May 7, 2019 at 22:16
  • \$\begingroup\$ @jsotola, \$2^{5}=32\$, doesn't it? \$\endgroup\$
    – The Photon
    May 7, 2019 at 22:54
  • \$\begingroup\$ you are correct .... it's just that the OP is using the word "must" ..... the question reads like a school test question .... those are tricky sometimes \$\endgroup\$
    – jsotola
    May 8, 2019 at 0:34

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