Digital logic: gates, K-maps & flip-flops worksheet with answers

Free printable Digital logic: gates, K-maps & flip-flops worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
ABCN1G1G2G3F

For the logic circuit shown, how many of the 8 combinations of the inputs A, B and C give the output F = 1? Find N.

A, B, C → F
N =
2.Easy
ABC0001111001

Click the cell of the 3-variable Karnaugh map that belongs to minterm m4 (variables A, B, C with A the most significant bit).

m4
  1. 1A = 0, BC = 00
  2. 2A = 0, BC = 01
  3. 3A = 0, BC = 11
  4. 4A = 0, BC = 10
  5. 5A = 1, BC = 00
  6. 6A = 1, BC = 01
  7. 7A = 1, BC = 11
  8. 8A = 1, BC = 10
3.Medium
ABCD000111100001111010010312040507060121130150140819111010

Use the Karnaugh map to find the minimal product-of-sums (POS) form of F(A, B, C, D) = Σm(0, 2, 9, 11, 13). How many sum terms (factors) N does it have?

F(A, B, C, D) = Σm(0, 2, 9, 11, 13)
N =
4.Medium
ABC00011110011011031204050706

Use the Karnaugh map to find the minimal product-of-sums (POS) form of F(A, B, C) = Σm(0, 1, 2). How many sum terms (factors) N does it have?

F(A, B, C) = Σm(0, 1, 2)
N =
5.Hard
CLKJK123456

A positive-edge-triggered JK flip-flop starts with Q = 0 and receives the inputs shown at 6 rising clock edges. How many times N does Q change state?

Q₀ = 0JK
N =
6.Hard
CLKJK12345678

A positive-edge-triggered JK flip-flop starts with Q = 0 and receives the inputs shown. Click the first clock edge at which Q goes from 1 back to 0.

Q₀ = 0JK
  1. 1clock edge 1
  2. 2clock edge 2
  3. 3clock edge 3
  4. 4clock edge 4
  5. 5clock edge 5
  6. 6clock edge 6
  7. 7clock edge 7
  8. 8clock edge 8

Answer key

  1. 1. N = 1
  2. 2. A = 1, BC = 00
  3. 3. N = 4
  4. 4. N = 2
  5. 5. N = 3
  6. 6. clock edge 6

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