1. ECE/CS 352 Digital System Fundamentals© T. Kaminski & C. Kime 1 ECE/CS 352 Digital Systems Fundamentals Spring 2001 Chapter 3 -Part 2 Tom Kaminski & Charles R. Kime

2. ECE/CS 352 Digital System Fundamentals Chapter3 Page 2 Functional Block: Decoders

3. ECE/CS 352 Digital System Fundamentals Chapter3 Page 3 2-to-4 Line Decoder

4. ECE/CS 352 Digital System Fundamentals Chapter3 Page 4 2-to-4 Line Demultiplexer

5. ECE/CS 352 Digital System Fundamentals Chapter3 Page 5 Example: 74F138 Demultiplexer Note: This "Truth Table" uses the "x" to mean "this could be either 0 or 1". Thus, it "compacts" some of 2 6 = 64 lines.

6. ECE/CS 352 Digital System Fundamentals Chapter3 Page 6 Implementing Logic with Decoders

7. ECE/CS 352 Digital System Fundamentals Chapter3 Page 7 Example 1: F(A,B) =  m(0,3)

8. ECE/CS 352 Digital System Fundamentals Chapter3 Page 8 Example 1: F(X,Y,Z) =  m(0,3,5,6)

9. ECE/CS 352 Digital System Fundamentals Chapter3 Page 9 Implementing Larger Minterms

10. ECE/CS 352 Digital System Fundamentals Chapter3 Page 10 Functional Block: Encoders

11. ECE/CS 352 Digital System Fundamentals Chapter3 Page 11 Review: Decoders and Encoders

12. ECE/CS 352 Digital System Fundamentals Chapter3 Page 12 Multiplexers

13. ECE/CS 352 Digital System Fundamentals Chapter3 Page 13 Example: A 4-to-1 multiplexer

14. ECE/CS 352 Digital System Fundamentals Chapter3 Page 14 Multiplexer Versus Decoder Note how similar the two are internally.

15. ECE/CS 352 Digital System Fundamentals Chapter3 Page 15 Functions with Multiplexers

16. ECE/CS 352 Digital System Fundamentals Chapter3 Page 16 Example: Gray to Binary Code

17. ECE/CS 352 Digital System Fundamentals Chapter3 Page 17 Gray to Binary (Continued)

18. ECE/CS 352 Digital System Fundamentals Chapter3 Page 18 Gray to Binary (Continued)

19. ECE/CS 352 Digital System Fundamentals Chapter3 Page 19 Gray to Binary (Continued)

20. ECE/CS 352 Digital System Fundamentals Chapter3 Page 20 Other MUX Implementations A C B Y 1 1 1 1 00011011 D0D0 D1D1 D2D2 D3D3 0 0 0 0 A C B Z 0 1 0 1 00011011 D0D0 D1D1 D2D2 D3D3 0 11 0 AA AA AA

21. ECE/CS 352 Digital System Fundamentals Chapter3 Page 21 MUX Implementations (Cont.)

22. ECE/CS 352 Digital System Fundamentals Chapter3 Page 22 MUX: (Cont.) Factoring Out C

23. ECE/CS 352 Digital System Fundamentals Chapter3 Page 23 MUX: (Cont.) Factoring out B

24. ECE/CS 352 Digital System Fundamentals Chapter3 Page 24 MUX: (Cont.) Factoring out A

25. ECE/CS 352 Digital System Fundamentals Chapter3 Page 25 Summary Know the functions performed by the following functional blocks: Decoders Demultiplexers Encoders Multiplexers Know how to implement Boolean functions using: Multiplexers Decoders