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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Name: ____________________   Date: ____________

1.Easy
ABCF000?001?010?011?100?101?110?111?

The function F = A′ + C′ + B′ is 0 for exactly one combination of the inputs. Click that row of the truth table.

F = A′ + C′ + B′
  1. 1ABC = 000
  2. 2ABC = 001
  3. 3ABC = 010
  4. 4ABC = 011
  5. 5ABC = 100
  6. 6ABC = 101
  7. 7ABC = 110
  8. 8ABC = 111
2.Easy
A = 0B = 0C = 0G1N1G2F

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. 1N1
  2. 2G1
  3. 3G2
3.Medium
MUXCI0​1I1​0I2​C′I3​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 = 1, I₂ = 0, I₃ = C′. For how many of the 8 combinations of A, B and C is the output F = 1? Find N.

I₀ = CI₁ = 1I₂ = 0I₃ = C′
N =
4.Medium
ABC000111100101324576

Simplify F = ABC + A′C′ + BC′ to its minimal sum-of-products form. How many literals L does the simplified expression contain?

F = ABC + A′C′ + BC′
L =
5.Hard
ABCD000111100001111010010302140507X6112X130151140809011110

Find the minimal SOP form of F(A, B, C, D) = Σm(0, 4, 10, 12, 14) + d(6, 13), where d marks the don't-care conditions. How many literals L does it contain?

F(A, B, C, D) = Σm(0, 4, 10, 12, 14) + d(6, 13)
L =
6.Hard
DQ3​Q3​DQ2​Q2​DQ1​Q1​DQ0​Q0​CLKRING

A 4-bit ring counter Q₃Q₂Q₁Q₀ starts at 1000. At every clock edge the bits shift one place to the right (Q₃ → Q₂ → Q₁ → Q₀) and Q₃ receives Q₀. Give the state Q = Q₃Q₂Q₁Q₀ as a decimal number after 3 clock edges.

Q₃Q₂Q₁Q₀ = 10003
Q =

Answer key

  1. 1. ABC = 111
  2. 2. N1
  3. 3. N = 4
  4. 4. L = 4
  5. 5. L = 8
  6. 6. Q = 1

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