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.

New worksheet Practise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________ Date: ____________

1.Easy

The propagation delay of every gate is written under it. Find the worst-case propagation delay t_pd from the inputs to the output F.

N1: 1 nsG1: 2 nsG2: 5 ns

t_pd = ns

2.Easy

NAND and NOR are universal gates: any logic function can be built from one of them alone. What is the minimum number N of 2-input NAND gates needed to build the AND function shown?

F = A·B

N =

3.Medium

Use the Karnaugh map to find the minimal sum-of-products (SOP) form of F(A, B, C, D) = Σm(0, 4, 7, 8, 9, 10, 15). How many product terms N does it have?

F(A, B, C, D) = Σm(0, 4, 7, 8, 9, 10, 15)

N =

4.Medium

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

I₀ = 1I₁ = C′I₂ = CI₃ = 1

N =

5.Hard

Find the minimal SOP form of F(A, B, C, D) = Σm(0, 2, 4, 6, 8, 11, 13) + d(7, 9, 14), where d marks the don't-care conditions. How many product terms N does it have?

F(A, B, C, D) = Σm(0, 2, 4, 6, 8, 11, 13) + d(7, 9, 14)

N =

6.Hard

For F(A, B, C, D) = Σm(0, 1, 2, 4, 5, 8, 11, 12, 15) + d(7, 13), where d marks the don't-care conditions, find the number N of essential prime implicants.

F(A, B, C, D) = Σm(0, 1, 2, 4, 5, 8, 11, 12, 15) + d(7, 13)

N =

Answer key

1. t_pd = 7 ns
2. N = 2
3. N = 4
4. N = 6
5. N = 4
6. N = 4

Full step-by-step solutions: practise this topic on examproblems.com.