Glory - MuxDemuxvygytftftftgyguyhuhyufd57.pptx

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1. Multiplexer, Demultiplexer, Encoder and Decoder J. GLORY PRECIOUS M.E.,(Ph.D)., ASSISTANT PROFESSOR DEPARTMENT OF BIOMEDICAL ENGINEERING RAJALAKSHMI ENGINEERING COLLEGE

2. Multiplexer (MUX) A MUX is a digital switch that has multiple inputs (sources) and a single output (destination). The select lines determine which input is connected to the output. MUX Types  2-to-1 (1 select line)  4-to-1 (2 select lines)  8-to-1 (3 select lines)  16-to-1 (4 select lines) Multiplexer Block Diagram Select Lines Inputs (sources) Output (destination) 1 2 N N MUX

3. Multiplexer (Data Selectors) The term Multiplexer means many into one. Multiplexing is the process of transmitting a large number of information over a single line. A Digital Multiplexer (MUX) is a combinational Circuit that select one digital information from several sources and transmits the selected information on a single output line. A Multiplexer is also called a Data Selector. The Multiplexer has several data input line and a single output line.

4. Cont. MUX directs one of the inputs to its output line by using a control bit word ( selection line) to its select lines. Multiplexer contains the followings: data inputs selection inputs a single output Selection input determines the input that should be connected to the output. The multiplexer acts like an electronic switch that selects one from different.

5. MULTIPLEXERS Multiplexer

6. Typical Application of a MUX MP3 Player Docking Station Laptop Sound Card Digital Satellite Digital Cable TV Surround Sound System MUX D0 D1 D2 D3 Y B A Selected Source MP3 1 Laptop 1 Satellite 1 1 Cable TV Multiple Sources Single Destination Selector

7. 4-to-1 Multiplexer (MUX) B A Y D0 1 D1 1 D2 1 1 D3 MUX D0 D1 D2 D3 Y B A Y=A’B’D0+AB’D1+A’BD2+ABD3

8. 4-to-1 Multiplexer Waveforms D0 D1 D2 D3 A B Y D0 D1 D2 D3 D0 D1 D2 D3 Input Data Select Line Output Data

9. Medium Scale Integration MUX 4-to-1 MUX 8-to-1 MUX 16-to-1 MUX Inputs Select Enable Output (Y) (and inverted output) Y=A’B’Ç’D0+A’B’CD1+A’B C’D2

10. 8-1 Multiplexer Circuit

11. Demultiplexer (DEMUX) A DEMUX is a digital switch with a single input (source) and a multiple outputs (destinations). The select lines determine which output the input is connected to. DEMUX Types  1-to-2 (1 select line)  1-to-4 (2 select lines)  1-to-8 (3 select lines)  1-to-16 (4 select lines) Demultiplexer Block Diagram Select Lines Input (source) Outputs (destinations) 2 N 1 N DEMUX

12. De-Multiplexer The De-Multiplexer is a combinational logic circuit that performs the reverse operation of multiplexer (Several output lines, one input line). De -Multiplexer means one to many. A De-Multiplexer is a circuit with one input and many output. By applying control signal, we can steer any input to the output. De-Multiplexer is the process of taking information from one input and transmitting the same over one of several outputs.

13. DEMULTIPLEXERS/DECODERS AND THEIR USE IN COMBINATIONAL LOGIC DESIGN Demultiplexer

14. Typical Application of a DEMUX Single Source Multiple Destinations Selector D0 D1 D2 D3 X DEMUX B A Selected Destination B/W Laser Printer 1 Fax Machine 1 Color Inkjet Printer 1 1 Pen Plotter B/W Laser Printer Color Inkjet Printer Pen Plotter Fax Machine

15. 1-to-4 De-Multiplexer (DEMUX) B A D0 D1 D2 D3 X 1 X 1 X 1 1 X D0 D1 D2 D3 X B A DEMUX

16. 1-to-4 De-Multiplexer Waveforms X S0 S1 D0 D1 D2 D3 Output Data Select Line Input Data

17. Medium Scale Integration DEMUX 1-to-4 DEMUX 1-to-8 DEMUX 16-to-1 MUX Select Input (inverted) Outputs (inverted) Most Medium Scale Integrated (MSI) DEMUXs have inverted outputs. This is done because it requires few logic gates to implement DEMUXs with inverted outputs rather than no-inverted outputs.

18. Applications of Multiplexer Communication system – Communication system is a set of system that enable communication like transmission system, relay and tributary station, and communication network. The efficiency of communication system can be increased considerably using multiplexer. Multiplexer allow the process of transmitting different type of data such as audio, video at the same time using a single transmission line. Computer Memory –  A Multiplexer is used in computer memory to keep up a vast amount of memory in the computers, and also to decrease the number of copper lines necessary to connect the memory to other parts of the computer.

19. Applications of De-Multiplexer Communication System - Communication system use multiplexer to carry multiple data like audio, video and other form of data using a single line for transmission. This process make the transmission easier. The demultiplexer receive the output signals of the multiplexer and converts them back to the original form of the data at the receiving end. The multiplexer and demultiplexer work together to carry out the process of transmission and reception of data in communication system.

20. DECODERS Decoder is a combinational circuit that converts binary information from “n” input lines to a maximum of 2 n unique output lines .If the n-bit coded information has unused combinations ,the decoder may have fewer than 2 n outputs.

21. Decoder

22. Decoders with Enable Decoders with Enable (1/2) Decoders often come with an enable signal, so that the device is only activated when the enable, E=1. Truth table: Q = ES 1 'S ' Q 1 = ES 1 'S Q 2 = ES 1 S ' Q 3 = ES 1 S S 1 S E Circuit:

23. Demultiplexer Demultiplexer Vs Decoder The demultiplexer is actually identical to a decoder with enable, as illustrated below: Exercise: Provide the truth table for above demultiplexer . 2x4 Decoder D S 1 S Y = D.S 1 '.S ' Y 1 = D.S 1 '.S Y 2 = D.S 1 .S ' Y 3 = D.S 1 .S E

24. A Demux Using NAND Gates: A Decoder with an Enable

25. Dr Mohamed A Berbar

26. Thankyou