CPU design and Architecture Part -2

CPU Design and Architecture Part -2

1. Program Counter

Program Counter is very Important basic unit of CPU because it is that circuit which Directs/point the CPU to the Instructions stored in Memory.

For one complete execution of instruction, CPU fetches the instructions from memory and then decode it and then execute it in the way in which programmer wished. Program counter actually directs the CPU to next instruction and it has nothing to do with rest of the processes which CPU performs. Program Counter is abbreviated as PC.

Program Counter is consisted of a counter circuit. The counter circuit used in Program Counter is of very special type. Actually, This counter is designed in such a way that it can count up, it can count down, it can jump one unit up, it can jump one unit down, it can also jump to any specified number to which a programmer wish.

Counters are made up of T-Flip Flops, and it is also easy to design them to count up or down BUT how to design them to JUMP???

YES! the answer is that, such a counter can be made by using an another sub part with it which is called FULL-ADDER. Thus we would need a full adder to implement such a counter which can JUMP to any specified number. For example, if present counting number is 1 and i wish to JUMP to 5 then i would add 4 to the present counting number and i would get the required result from the output of the full adder. That is it! So simple!

More on that in Next post, Enjoy!

Digital basic circuits

AND Gate

AND gate is a two input and one output circuit.

If both inputs of the AND gate are high/1 then the output is high/1 Else output is Low/0.

Let we name one of the inputs as A and other as B. Let we also name the output as X then;

Truth Table

Input A---- Input B----- output X
low/0 ------low/0 ------low/0
low/0 ------high/1 ------low/0
high/1------low/0 ------low/0
high/1------high/1------high/1


OR Gate

OR gate is also a two input and one output circuit.

If any one of the inputs is high/1 then the output is high/1 Else output is Low/0

Let we name one of the inputs as A and other as B. Let we also name the output as X then;

Truth Table

Input A---- Input B----- output X
low/0 ------low/0 ------low/0
low/0 ------high/1 ------high/1
high/1------low/0 ------high/1
high/1------high/1------high/1

Digital basic circuits

AND Gate

AND gate is a two input and one output circuit.

If both inputs of the AND gate are high/1 then the output is high/1 Else output is Low/0.

Let we name one of the inputs as A and other as B. Let we also name the output as X then;

Truth Table

Input A---- Input B----- output X
low/0 ------low/0 ------low/0
low/0 ------high/1 ------low/0
high/1------low/0 ------low/0
high/1------high/1------high/1


OR Gate

OR gate is also a two input and one output circuit.

If any one of the inputs is high/1 then the output is high/1 Else output is Low/0

Let we name one of the inputs as A and other as B. Let we also name the output as X then;

Truth Table

Input A---- Input B----- output X
low/0 ------low/0 ------low/0
low/0 ------high/1 ------high/1
high/1------low/0 ------high/1
high/1------high/1------high/1

Beauty Tips

Beauty Tips

Today in this Post i am going to mention some beauty tips for you.

Well, It is well said that beauty is not in the well structure of a person but it lies in the goodness of that person. A person may be very nice looking but his/her bad attitude ruin his/her superficial beauty. So, the beauty that is superficial is not long living.

A person should not worry about his/her superficial beauty rather he/she should worry about his/her goodness. That goodness is the key to success. Nobody can forget that person who is good, honest and innocent. So, why should i worry about my acne, pimples etc? These are not so bad than my bad habits. They will never lead to my failure but my bad habits can lead to failure.

Hmm . . It is not a lecture my friends!

I believe that beauty can help in confidence of a person. Beauty can not be neglected. Beauty of a person is the thing for which lovers want to die. Beauty attracts and creates a strange love in the heart of a person. But it cannot give real happiness to a person as it is just felt by eyes not by heart. Heart needs beauty and well being of a person. Hence, We should not worry too much about our beauty. Beauty can be achieved by using modern cosmetic products and so, everybody can have a taste of it.

Modern surgical methods are also available for getting different types of beauty( it may seem humorous) for example, one can transplant hairs, teeth, skin color etc.

My friends, Nobody is ugly, ugly is that heart which think so. God has created everything fine and beautiful, but that beauty can be felt when one see through eyes of the heart.


Good Bye till another Post, Enjoy!

How to Sing a Song

Singing Enthusiasm

Hmm... You have chosen a best way to express your love with your Girlfriend by singing them in your sweet voice!

Often it is easier to express your love in singing way rather than by direct way, because in direct way, you may feel shy or you may feel some hesitation or you may be afraid of losing your best and sweet girlfriend if you did some mistake in describing your love before her.

When you express your love in a singing way then every thing is fair! Because after all song is a song! Song does not care much about your words whereas it cares about your feelings that you express in your voice.

But How to sing a Song?? or at least some ordinary words??

The answer to this question is simple. Simple??? Yea! everything is simple for LOVERS!

Tips For Singing

• Listen to your words, rise and fall and pauses when you sing.
• You should feel such that no one is listening to you although you may be singing before a big gathering.
• Always concentrate on your words, this will help you to minimize fearing and hesitation.
• Don't care that what are you singing, just keep in mind that how you are singing.
• Always concentrate on your rise and fall of your voice, i.e before uttering each word you should think that how it would be felt if i stretch it, rise it or fall it and then sing them.
• Don't care that whether audience are happy with your song or not. Decide it when you have sung it.
• Always SING WITH FULL OPEN MOUTH. Don't feel shy, when you practice it then you will start comfortable with it. If you don't follow this important tip then you may never sing a song, or you may try but this would not be song.
• Again sing your song with full open mouth and feel that as i am born free so i am singing free without any shame or so.
• Try to sing with your tape players etc
• Try to record your song and listen it to judge and improve your voice.

Now sing your songs and impress your Girlfriend!
hmmm for the female to impress her Boyfriend!

There are a lot of other tips that i will share with you later. Enjoy!

Digital Circuits Basics

Digital Circuits Basics

There are Three basic circuits/units in digital systems; These are:

1. NOT Gate
2. AND Gate
3. OR Gate

Rest of the everything/circuits are made from these basic gates. So they are well termed as GATES!!

1. NOT GATE

Not gate is a one input and one output circuit.

Not Gate Operation
when the input of NOT gate in connected with negative terminal of the battery then its output is full positive, BUT when NOT gate input is connected with positive terminal of the battery then its output is full Negative.

In short, NOT gate output is inverse of the input, i.e NOT gate output is complement of the input.

In digital systems, We define the negative input or output as Low/0 AND positive input or output as High/1.

Truth Table for NOT gate
INPUT OUTPUT
negative/0 positive/1
positive/1 negative/0


Well, We will discuss other Gates also in another posts. So learn and convey, Enjoy!

CPU design and architecture

CPU design and architecture

CPU stands for “Central Processing Unit”. High level CPU design is easy to understand if a person knows how to design simple as possible computer/CPU. ‘Simple As Possible computer’ is abbreviated as “SAP”.

In a computer, mobile phones, digital music players, remote control, TV circuits, automatic machines etc, CPU plays central and vital role in their working. CPU is just like the “BRAIN” which is common in every creature BUT rest of the structure is different in them. Following similar concept, we come to know that computer, mobile phones, digital music players, remote control , automatic machines etc, have CPU in common But rest of the structure differs.

CPU is just one part of the whole structure and it is responsible to make ‘CALCULATIONS/DECISION and ORDERS’ only. Any thing that only makes ‘calculations/decision and an order’ is not capable of doing any real thing. Although I have brain but if I was unfortunate and had no hands then how could I write this article? If I was unable to hear then I would be called DEAF although having the same brain as normal human being. Following similar concept, computers and other automatic machines have only structural difference and they have CPU circuit in common. Hence, CPU circuit gets top position in controlled circuits.

One main advantage of controlled circuits that uses CPU circuit is that they are programmable. This implies that one can get multiple functions from same circuit by reprogramming it in desired way. Computer which uses CPU follows our instructions and we can get desired work out of it by installing software which contains our desired instructions.


At the end one important question arises!!!
Although we are convinced that CPU is basic unit of every controlled circuit
BUT

WHAT is its internal circuit and how it WORKS???

CPU internal Circuit and Working

Truly saying CPU is combination of REGISTERS, COUNTERS, FLIP-FLOPS, HALF ADDERS, FULL ADDERS, MULTIPLEXERS, DEMULTIPLEXERS, ENCODERS, DECODERS, AND SOME BASIC GATES.

CPU has FIVE main circuits/units which are made from above mentioned sub circuits. These five main units are listed below.

1. Program Counter
2. Memory
3. Control Unit
4. Arithmetic Logic Unit
5. Accumulator

OK, now wait for further details on these basic units. I will publish them in other posts! Enjoy!