Friday 30 March 2012

CURRENTLY WORKING AS ASSISTANT PROFESSOR AT RMK ENGINEERING COLLEGE

Monday 25 July 2011

Friday 3 June 2011

MOTIVATIONAL QUOTES


Motivational Quotes
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A creative man is motivated by the desire to achieve, not by the desire to beat others.
Ayn Rand 

Act as if what you do makes a difference. It does.
William James 

Always continue the climb. It is possible for you to do whatever you choose, if you first get to know who you are and are willing to work with a power that is greater than ourselves to do it.
Ella Wheeler Wilcox 

Always desire to learn something useful.
Sophocles 

Always do your best. What you plant now, you will harvest later.
Og Mandino 

Be gentle to all and stern with yourself.
Saint Teresa of Avila 

Be miserable. Or motivate yourself. Whatever has to be done, it's always your choice.
Wayne Dyer 

Be thine own palace, or the world's thy jail.
John Donne 

Begin to be now what you will be hereafter.
William James 

Believe in yourself! Have faith in your abilities! Without a humble but reasonable confidence in your own powers you cannot be successful or happy.
Norman Vincent Peale 

Crave for a thing, you will get it. Renounce the craving, the object will follow you by itself.
Swami Sivananda 

Determine never to be idle. No person will have occasion to complain of the want of time who never loses any. It is wonderful how much may be done if we are always doing.
Thomas Jefferson 

Do not weep; do not wax indignant. Understand.
Baruch Spinoza 

Do you want to know who you are? Don't ask. Act! Action will delineate and define you.
Thomas Jefferson 

Either you run the day or the day runs you.
Jim Rohn 

Even if you fall on your face, you're still moving forward.
Victor Kiam 

Expect problems and eat them for breakfast.
Alfred A. Montapert 

Fear cannot be without hope nor hope without fear.
Baruch Spinoza 

Follow your dreams, work hard, practice and persevere. Make sure you eat a variety of foods, get plenty of exercise and maintain a healthy lifestyle.
Sasha Cohen 

Go big or go home. Because it's true. What do you have to lose?
Eliza Dushku 

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JAI HIND

Monday 9 May 2011

encoders



                                           
../images/main/bullet_green_ball.gifEncoders
An encoder is a combinational circuit that performs the inverse operation of a decoder. If a device output code has fewer bits than the input code has, the device is usually called an encoder. e.g. 2n-to-n, priority encoders.
  
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The simplest encoder is a 2n-to-n binary encoder, where it has only one of 2ninputs = 1 and the output is the n-bit binary number corresponding to the active input.
  
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../images/digital/encoder.gif
  
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 ../images/main/bulllet_4dots_orange.gifExample - Octal-to-Binary Encoder
Octal-to-Binary take 8 inputs and provides 3 outputs, thus doing the opposite of what the 3-to-8 decoder does. At any one time, only one input line has a value of 1. The figure below shows the truth table of an Octal-to-binary encoder.
  
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Truth Table
  
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I0
I1
I2
I3
I4
I5
I6
I7
Y2
Y1
Y0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
0
0
1
1
0
0
0
0
1
0
0
0
1
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
0
0
0
0
1
0
1
1
0
0
0
0
0
0
0
0
1
1
1
1
  
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For an 8-to-3 binary encoder with inputs I0-I7 the logic expressions of the outputs Y0-Y2 are:
  
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Y0 = I1 + I3 + I5 + I7
Y1= I2 + I3 + I6 + I7
Y2 = I4 + I5 + I6 +I7
  
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Based on the above equations, we can draw the circuit as shown below
  
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Circuit
  
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../images/digital/encoder_8to3.gif
  
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 ../images/main/bulllet_4dots_orange.gifExample - Decimal-to-Binary Encoder
Decimal-to-Binary take 10 inputs and provides 4 outputs, thus doing the opposite of what the 4-to-10 decoder does. At any one time, only one input line has a value of 1. The figure below shows the truth table of a Decimal-to-binary encoder.
  
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Truth Table
  
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I0
I1
I2
I3
I4
I5
I6
I7
I8
I9
Y3
Y2
Y1
Y0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
0
0
0
0
0
1
1
0
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
0
1
0
1
0
0
0
0
0
0
1
0
0
0
0
1
1
0
0
0
0
0
0
0
0
1
0
0
0
1
1
1
0
0
0
0
0
0
0
0
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
1
  
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From the above truth table , we can derive the functions Y3, Y2, Y1 and Y0 as given below.
  
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Y3 = I8 + I9
Y2 = I4 + I5 + I6 + I7
Y1 = I2 + I3 + I6 + I7
Y0 = I1 + I3 + I5 + I7 + I9
  
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 ../images/main/bullet_green_ball.gifPriority Encoder
If we look carefully at the Encoder circuits that we got, we see the following limitations. If more then two inputs are active simultaneously, the output is unpredictable or rather it is not what we expect it to be.
  
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This ambiguity is resolved if priority is established so that only one input is encoded, no matter how many inputs are active at a given point of time.
  
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The priority encoder includes a priority function. The operation of the priority encoder is such that if two or more inputs are active at the same time, the input having the highest priority will take precedence.
  
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 ../images/main/bulllet_4dots_orange.gifExample - 4to3 Priority Encoder
The truth table of a 4-input priority encoder is as shown below. The input D3 has the highest priority, D2 has next highest priority, D0 has the lowest priority. This means output Y2 and Y1 are 0 only when none of the inputs D1, D2, D3 are high and only D0 is high.
  
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A 4 to 3 encoder consists of four inputs and three outputs, truth table and symbols of which is shown below.
  
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Truth Table
  
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D3
D2
D1
D0
Y2
Y1
Y0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
0
0
1
x
0
1
0
0
1
x
x
0
1
1
1
x
x
x
1
0
0
  
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Now that we have the truth table, we can draw the Kmaps as shown below.
  
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Kmaps
  
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../images/digital/priority_kmap.gif
  
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From the Kmap we can draw the circuit as shown below. For Y2, we connect directly to D3.
  
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../images/digital/pri_encoder_yo.gif
  
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We can apply the same logic to get higher order priority encoders.
  
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