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
ABCN1G1N2G2F

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
A = 0B = 0C = 0G1G2G3F

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

A = 0B = 0C = 0
  1. 1G1
  2. 2G2
  3. 3G3
3.Medium
MUXCI0​CI1​1I2​1I3​ABS1​S0​F

A 4-to-1 multiplexer has its select inputs S₁ = A and S₀ = B, and its data inputs tied to I₀ = C, I₁ = C, I₂ = 1, I₃ = 1. For how many of the 8 combinations of A, B and C is the output F = 1? Find N.

I₀ = CI₁ = CI₂ = 1I₃ = 1
N =
4.Medium
ABCD000111100001111010011302040507061121131151141819111010

Use the Karnaugh map to find the minimal sum-of-products (SOP) form of F(A, B, C, D) = Σm(0, 3, 8, 9, 11, 12, 13, 14, 15). How many product terms N does it have?

F(A, B, C, D) = Σm(0, 3, 8, 9, 11, 12, 13, 14, 15)
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 at 8 rising clock edges. How many times N does Q change state?

Q₀ = 0JK
N =

Answer key

  1. 1. N = 3
  2. 2. G2
  3. 3. N = 6
  4. 4. N = 4
  5. 5. N = 5
  6. 6. N = 3

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