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 worksheetPractise 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
ABCD0001111000011110

Click the cell of the 4-variable Karnaugh map that belongs to minterm m8 (variables A, B, C, D with A the most significant bit).

m8
  1. 1AB = 00, CD = 00
  2. 2AB = 00, CD = 01
  3. 3AB = 00, CD = 11
  4. 4AB = 00, CD = 10
  5. 5AB = 01, CD = 00
  6. 6AB = 01, CD = 01
  7. 7AB = 01, CD = 11
  8. 8AB = 01, CD = 10
  9. 9AB = 11, CD = 00
  10. 10AB = 11, CD = 01
  11. 11AB = 11, CD = 11
  12. 12AB = 11, CD = 10
  13. 13AB = 10, CD = 00
  14. 14AB = 10, CD = 01
  15. 15AB = 10, CD = 11
  16. 16AB = 10, CD = 10
2.Easy
ABCG13 nsN1: 2 nsG24 nsG33 nsF

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

N1: 2 nsG1: 3 nsG2: 4 nsG3: 3 ns
tpd = ns
3.Medium
ABCD000111100001111010111312041507060121130151140809111110

Use the Karnaugh map to find the minimal product-of-sums (POS) form of F(A, B, C, D) = Σm(0, 1, 2, 3, 5, 10, 11, 13, 14). How many sum terms (factors) N does it have?

F(A, B, C, D) = Σm(0, 1, 2, 3, 5, 10, 11, 13, 14)
N =
4.Medium
ABCD000111100001111010010302141507060121130150140819011010

Use the Karnaugh map to find the minimal sum-of-products (SOP) form of F(A, B, C, D) = Σm(0, 4, 5, 9, 13). How many literals L does it contain in total (a primed variable counts as one literal)?

F(A, B, C, D) = Σm(0, 4, 5, 9, 13)
L =
5.Hard
ABCD0001111000011110100103X21405X706112013X151140819111110

Find the minimal SOP form of F(A, B, C, D) = Σm(0, 4, 9, 10, 11, 12, 14) + d(2, 7, 15), where d marks the don't-care conditions. How many product terms N does it have?

F(A, B, C, D) = Σm(0, 4, 9, 10, 11, 12, 14) + d(2, 7, 15)
N =
6.Hard
ABCD00011110000111100001031204051706112013015X140819X11X10

For F(A, B, C, D) = Σm(2, 7, 9, 12) + d(10, 11, 14), where d marks the don't-care conditions, find the number N of essential prime implicants.

F(A, B, C, D) = Σm(2, 7, 9, 12) + d(10, 11, 14)
N =

Answer key

  1. 1. AB = 10, CD = 00
  2. 2. tpd = 9 ns
  3. 3. N = 4
  4. 4. L = 9
  5. 5. N = 4
  6. 6. N = 4

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