I have to create a two level circuit NAND only gates for the Fibonacci from 1-8. After creating a truth table and K-Maps, I got the Function F=A'B + B'C. Then I drew the AND-OR circuit and tried to convert it NAND only circuit. After implementing it on our bread board, I did not get the correct output, so I am guessing something is wrong with my circuit diagram. I am not sure. For the truth table that we were given, the directions given were:

Each row in the truth table is identified by a decimal number. For each row that corresponds to a Fibonacci number, specify the output to be 1. Otherwise, specify the output to be 0.

Truth table


Circuit Diagram

  • \$\begingroup\$ Do you understand what the Fibonacci sequence is..... \$\endgroup\$
    – Trevor_G
    Mar 7, 2018 at 20:44
  • 1
    \$\begingroup\$ In States 4 to 7, A should be 1. Which makes your truth table so wrong. But you have a correct term \$\bar B C\$, even though K-map is wrong. \$\endgroup\$ Mar 7, 2018 at 21:34
  • \$\begingroup\$ The truth table is the one we received, we had to fill in the Fib.Num column. So when the minterm number is within the Fibonacci sequence, then we put a 1 in that column, else put a 0. The original truth table was from 0-15 so the last 8 rows were all 1s, but for this one, it has to be from 0-7. We just cut the table in half \$\endgroup\$ Mar 7, 2018 at 21:48
  • 1
    \$\begingroup\$ When you cut the truth table in half, you took the wrong half...because your truth table can't be true. \$\endgroup\$
    – Annie
    Mar 7, 2018 at 22:08
  • 3
    \$\begingroup\$ On two occasions I have been asked, — "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" -Charles Babbage \$\endgroup\$
    – Annie
    Mar 7, 2018 at 22:23

1 Answer 1


You can use the De Morgan theorems to convert any OR logic to AND and vice-versa:

!(A * B) = !A + !B


!(A + B) = !A * !B


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.