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
A = 0B = 1C = 0G1N1G2F

The inputs of the logic circuit are A = 0, B = 1 and C = 0. Exactly one of its gates has the output 0. Click that gate.

A = 0B = 1C = 0
  1. 1N1
  2. 2G1
  3. 3G2
2.Easy
A = 1B = 0C = 1G1G2G3F

The inputs of the logic circuit are A = 1, B = 0 and C = 1. Exactly one of its gates has the output 1. Click that gate.

A = 1B = 0C = 1
  1. 1G1
  2. 2G2
  3. 3G3
3.Medium
ABCD000111100001111000110302041517060120131150141819111110

Use the Karnaugh map to find the minimal sum-of-products (SOP) form of F(A, B, C, D) = Σm(1, 5, 7, 8, 9, 10, 11, 15). How many product terms N does it have?

F(A, B, C, D) = Σm(1, 5, 7, 8, 9, 10, 11, 15)
N =
4.Medium
ABC00011110010001131204150716

Use the Karnaugh map to find the minimal product-of-sums (POS) form of F(A, B, C) = Σm(2, 3, 5, 6). How many sum terms (factors) N does it have?

F(A, B, C) = Σm(2, 3, 5, 6)
N =
5.Hard
CLKT1234567

A positive-edge-triggered T flip-flop starts with Q = 0 and receives the inputs shown at 7 rising clock edges. How many times N does Q change state?

Q₀ = 0T
N =
6.Hard
ABCD00011110000111100001031204151706X12X131150141809X11X10

For F(A, B, C, D) = Σm(2, 5, 7, 8, 15) + d(10, 11, 12, 13), where d marks the don't-care conditions, find the number N of essential prime implicants.

F(A, B, C, D) = Σm(2, 5, 7, 8, 15) + d(10, 11, 12, 13)
N =

Answer key

  1. 1. N1
  2. 2. G1
  3. 3. N = 3
  4. 4. N = 3
  5. 5. N = 7
  6. 6. N = 2

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