Decoders
Download
1 / 60

Decoders - PowerPoint PPT Presentation


  • 125 Views
  • Uploaded on
  • Presentation posted in: General

Decoders. Usage of Decoders. Channel Selection: Generates Mutually Exclusive Channel Enabling/Disabling Signals (e.g. Multiplexers) Device Selection: Generates unique 1’s/0’s on output lines to turn on/off devices (e.g. decoder trees) Universal Function Implementation:

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Decoders

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Decoders


Usage of Decoders

Channel Selection:

Generates Mutually Exclusive Channel Enabling/Disabling Signals (e.g. Multiplexers)

Device Selection:

Generates unique 1’s/0’s on output lines to turn on/off devices (e.g. decoder trees)

Universal Function Implementation:

Serves as a device for implementing Boolean Functions on a Universal Basis

Coding and Decoding Information:

Can be used in a code/decode process (inputs can be recognized solely from outputs


Functional Description and Symbols


Where,

N = {1, 2, 3, …..}


Truth Table for a n-to-m Line Decoder


Truth Table for a n-to-m Line Decoder


Truth Table for a n-to-m Line Decoder (with enable)


Truth Table for a n-to-m Line Decoder (with enable)


Block-Symbolfor n-to-m Line Decoders

Where,

m = 2(n+1) – 1

n = {0,1, 2, 3, ….. , ∞}


Truth Table for a 1-to-2 Line Decoder


Block-Symbolfor 1-to-2 Line Decoders


Truth Table for a 2-to-4 Line Decoder


Block-Symbol for 2-to-4 Line Decoders


Truth Table for a n-to-m Active-Low Line Decoder


Truth Table for a n-to-m Line Active-Low Decoder (with enable)


Block-Symbolfor n-to-m Line Active-Low Decoders

Where,

m = 2(n+1) – 1

n = {0,1, 2, 3, ….. , ∞}


Decoder Trees


A Larger Decoder using smaller Decoders

2-to-4 Line Decoder using 1-to-2 Line Decoders


Device On/Off Truth Table


Device On/Off Truth Table


Device On/Off Truth Table


A Decoder Tree operates on the principle of unique device selection by a Decoder i.e. the Decoders in the final level/stage are used for generating the unique outputs as required, while decoders in the previous stages are employed for device selection (in this case the devices are decoders in the final stage).


Logical Truth Table of Decoder Tree


Logical Truth Table of Decoder Tree


Logical Truth Table of Decoder Tree


Logical Truth Table of Decoder Tree


Logical Truth Table of Decoder Tree


Logical Truth Table of Decoder Tree


Logical Truth Table of Decoder Tree


Logical Truth Table of Decoder Tree


3-to-8 Line Decoder using 1-to-2 & 2-to-4 Line Decoders


Boolean Function Realization


Function Implementation Using Decoders


Function Implementation Using Decoders


Function Implementation Using Decoders


Function Implementation Using Decoders


Function Implementation Using Decoders

f = m0 + m2

To implement the function we ‘OR’ the output pins d0 and d2 (which correspond to the Minterms m0 and m2).

Using Relationships established using Duality

f’ = m1 + m3

f = [ m1 + m3 ] ’

  • F(x1, x2, …. , xn) = ∑mR = ∏MS

  • [F(x1, x2, …. , xn)]’ = ∑mS = ∏MR


Function Implementation Using Decoders

f = m0 + m2

f’ = m1 + m3

f = [ m1 + m3 ] ’


Function Implementation Using Active-Low Decoders


Function Implementation Using Active-Low Decoders


Function Implementation Using Active-Low Decoders


Function Implementation Using Active-Low Decoders


Function Implementation Using Active-Low Decoders

f = M1 . M3

To implement the function we ‘OR’ the output pins d0 and d2 (which correspond to the Minterms m0 and m2).

Using Relationships established using Duality

f’ = M0 . M2

f = [ M0 . M2 ] ’

  • F(x1, x2, …. , xn) = ∑mR = ∏MS

  • [F(x1, x2, …. , xn)]’ = ∑mS = ∏MR


Function Implementation Using Active-Low Decoders

f = M1 . M3

f’ = M0 . M2

f = [ M0 . M2 ] ’


Multiple Output Function Implementation Using Decoders


Multiple Output Function Implementation Using Decoders


Multiple Output Function Implementation Using Decoders


Multiple Output Function Implementation Using Decoders


Multiple Output Function Implementation Using Decoders


ad
  • Login