Post on 09-Jan-2017
DESIGN AND SIMULATION OF DIFFERENT 8-BIT MULTIPLIERS USING VERILOG
CODE
BY
P. SAIKIRAN(12631A0469)M.SOUJANYA(12631A0488)S.VEERANNA(12631A04A7)N. SRINATH(12631A0496)
Under the Guidance of S. BALAIAH,M.Tech,(Ph.D)
Asso. Professor
1 Sri Venkateswara Engineering College
Sri Venkateswara Engineering College
Reasons for choosing this projectObjective of this project is to find a good multiplier to provide a
physically compact high speed and low power consumption unit.
Being a core part of arithmetic processing unit multipliers are in
extremely high demand on its speed and low power
consumption.
Multipliers play an important role in today’s digital signal
processing and various other applications.
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AIM
The main aim of this project is to design and simulation of
different 8-bit multipliers using VERILOG code
Considering their advantages and disadvantages these are
compared on the basis of area, speed and delay.
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ADDERS
In electronics, an adder is a digital circuit that performs
addition of two or more numbers.
Adders can be constructed for many numerical
representations, such as Binary-coded decimal or excess-3
Adders are different types in generally
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HALF ADDERThe half adder adds two single binary digits A and B.
It has two outputs, sum (S) and carry (C).
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FULL ADDERA full adder adds three one-bit numbers, often written as A, B,
and Cin.
A and B are the operands, and Cin is a bit carried in from the
previous less significant stage.
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Sri Venkateswara Engineering College
RIPPLE CARRY ADDER
• It is possible to create a logical circuit using multiple full adders to
add N-bit numbers.
• Each full adder inputs a Cin, which is the Cout of the previous adder.
This kind of adder is called a ripple-carry adder,
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CARRY SAVE ADDER
• If an adding circuit is to compute the sum of three or more numbers it
can be advantageous to not propagate the carry result.
• Instead, three input adders are used, generating two results a sum and a
carry.
• It is connected in vertically.
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MULTIPLICATIONMultiplication is a mathematical operation that at its
simplest is an abbreviated process of adding an integer
a specified number of times.
Multiplication of two k bit number needed multi
operand addition process that can be realized in k
cycles of shifting and addition with hardware,
firmware or software.
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MULTIPLICATION ALGORITHMIf the LSB of Multiplier is ‘1’, then add the multiplicand
into an accumulator.Shift the multiplier one bit to the right and multiplicand one
bit to the left.Stop when all bits of the multiplier are zero.
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CLASSIFICATION OF MULTIPLIERS
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USED MULTIPLIERS IN OUR PROJECT
Four multipliers used in our project:
Array multiplier
Wallace tree multiplier
Baugh wooley multiplier
Vedic multiplier
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ARRAY MULTIPLIER
An array multiplier is a digital combinational circuit
that is used for the multiplication of two binary
numbers by employing an array of full adders and half
adders.
Array multiplier is well known due to its regular structure.
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BLOCK DIAGRAM OF ARRAY MULTIPLIER
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Sri Venkateswara Engineering College
WALLACE TREE MULTIPLIER
The Wallace tree multiplier is considerably faster than a
simple array multiplier because its height is logarithmic in
word size, not linear.
As a result, Wallace trees are often avoided by designers,
while design complexity is a concern to them.
The Wallace tree multiplier is a high speed multiplier.
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BLOCK DIAGRAM OF WALLACE TREE MULTIPLIER
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Sri Venkateswara Engineering College
BAUGH WOOLEY MULTIPLIER
It is used for signed numbers multiplication
Baugh Wooley technique was developed to design direct
multipliers for two's complement numbers
When multiplying two's complement numbers directly,
each of the partial products to be added is a signed number.
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BLOCK DIAGRAM OF BAUGH WOOLEY MULTIPLIER
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Sri Venkateswara Engineering College
VEDIC MULTIPLIER
The multiplier is based on an algorithm URDHVA
TIRYAKBHYAM (Vertical & Crosswise) of ancient Indian
Vedic Mathematics.
URDHVA TIRYAKBHYAM SUTRA is a general
multiplication formula applicable to all cases of
multiplication.
It literally means “Vertically and crosswise”.
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BLOCK DIAGRAM OF VEDIC MULTIPLIER
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MULTIPLICATION OF TWO NUMBERS
using vedic multiplier
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Sri Venkateswara Engineering College
LANGUAGE USED IN OUR PROJECT
Verilog :
It is a hardware description language (HDL) used to model
electronic systems. It is most commonly used in the design and
verification of digital circuits at the register-transfer
level of abstraction.
There are different types of level of abstractions like date flow,
behavioral, etc.
In our project use dataflow modeling.
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COMPARISON OF MULTIPLIERS
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SOFTWARE TOOLS USED IN OUR PROJECT
Simulation: Xilinx ISE 14.7
Synthesis: Xilinx ISE 14.7
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APPLICATIONS
It is used in DSP applications.
It is used for filters and Fourier transforms.
These multipliers tend to consume most power in DSP
computations.
Is also used in ALU.
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ADVANTAGES
Reduced wire length.
High clock rate.
Small area.
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DISADVANTAGES
Reducing delay needs additional circuitry which
increases the chip area
Complexity of the circuit increases to reduce the
critical path of the propagation delay time
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FUTURE SCOPE
As an attempt to develop arithmetic algorithm and
architecture level optimization techniques for low-power
multiplier design, the research presented in this
dissertation has achieved good results and demonstrated
the efficiency of high level optimization techniques.
However, there are limitations in our work and several
future research directions are possible.
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CONCLUSIONAfter putting lot of hard efforts, we learnt that Baugh
Wooley multiplier is superior in all respect like speed, delay,
area, complexity, power consumption.
However Array Multiplier requires more power consumption
Delay for Array multiplier is larger than Wallace Tree
Multiplier.
Hence for low power requirement and for less delay
requirement Baugh Wooley multiplier is suggested.
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BIBLOGRAPHY
References websites:
www.slideshare.com
en.wikipedia.org
Reference books:
Khatibzadeh and K. Raahemifar, “A study &
comparison of full adder cells based on the standard
static logic,”
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THANK YOU
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Quires..?
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