1. Dept. of Electrical and Computer Eng., NCTU 1 Lab 7. 8-to-1 Multiplexer Presenter: Chun-Hsien Ko Contributors: Chung-Ting Jiang and Lin-Kai Chiu

2. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko Dept. of Electrical and Computer Eng., NCTU 2 What is multiplexer ( 多工器 ) ? Introduction 4-to-1 Multiplexer 8-to-1 Multiplexer LS74151 8-to-1 Multiplexer LAB: Use 8-to-1 multiplexer to implement circuit IC ： 74151 x 1 、 7404 x 1 、 7408 x 2 LED x 1 、 Switch x 1 、 Resister Network x 1

3. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko What is Multiplexer ( 多工器 ) ? It is expensive, if there has a specifically line between telephones for communication How to share the line? Multiplexer (Mux) and De-multiplexer (Demux) Sharing the resource (line) by time Dept. of Electrical and Computer Eng., NCTU 3

4. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko Dept. of Electrical and Computer Eng., NCTU 4

5. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko 8-to-1 Multiplexer Multiplexer also has different type, like: 8-to-4 Mux, 4-to-1 Mux, etc… Dept. of Electrical and Computer Eng., NCTU 5

6. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko LS74151 8-to-1 Multiplexer Strobe for enable the IC (connect to GND) W is inverted Y Dept. of Electrical and Computer Eng., NCTU 6

7. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko Dept. of Electrical and Computer Eng., NCTU 7 How to convert Y to F ?

8. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko Inspect equations and we can find that F has sum of 9 products Y has sum of 8 products Draw K-map to reduce F! If we reduce F to less or equal than 8 SOP, then we can use Y to represent F Dept. of Electrical and Computer Eng., NCTU 8

9. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko Reduce by K-map We start from 9 items Finally, we have 3 items A’CEF’G’ BC’D’EF ABCDEFG Dept. of Electrical and Computer Eng., NCTU 9

10. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko Finally, we have only 3 items A’CEF’G’ BC’D’EF ABCDEFG How can we implement with 8-to-1 multiplexer Use C, E, F as the selector of multiplexer If (C, E, F) = (1, 1, 0), output = A’G’ If (C, E, F) = (0, 1, 1), output = BD’ If (C, E, F) = (1, 1, 1), output = ABDG Otherwise, output = 0 Dept. of Electrical and Computer Eng., NCTU 10

11. Logic DesignLab 7. 8-to-1 MultiplexerChun-Hsien Ko LAB 7: Use 8-to-1 multiplexer to implement circuit IC ： 74151 x 1 、 7404 x 1 、 7408 x 2 LED x 1 、 Switch x 1 、 Resister Network x 1 A’CEF’G’ + BC’D’EF + ABCDEFG = C’E’F’ 0 + C’E’F 0 + C’EF’ 0 + C’EF BD’ + CE’F’ 0 + CE’F 0 + CEF’ A’G’ + CEF ABDG Please use other reduce method to do this lab Dept. of Electrical and Computer Eng., NCTU 11 LS 74151