Design and Implementation of 4×4 Vedic Multiplier using Cadence

Design and Implementation of 4×4 Vedic Multiplier using Cadence

Department of ECE, Rao Bahadur Y Mahabaleswarappa Engineering College PG Student, Department of ECE, RYMEC, Ballari ,Karanataka,India.

Abstract – Multipliers play an important role in todays digital signal processing and various other applications. Multiplier acts as a key block element in high speed arithmetic logic units, microcomputer, image processing etc. Multiplication process basically requires more hardware resources and computation time than addition and sub-traction process. In the recent years growth of the portable electronic is forcing the designers to optimize the existing design for better performance. Vedic mathematics have sixteen sutras but Urdhva-Triyagbhyam is mainly used. Vedic method for multiplication which is different from the process of normal multiplication is presented. This paper proposes the design of Vedic Multiplier using the techniques of Vedic Mathematics that have been modified to improve performance. Urdhva- Triyagbhyam is the most efficient algorithm that gives minimum delay for multiplication for all types of numbers irrespective of their size. To enhance speed numerous modifications over the standard modified booth algorithm, Wallace tree methods for – multiplier design have been made and several new techniques being worked upon. Amongst these Vedic multipliers based on Vedic mathematics are currently under focus.

Key Words: Vedic Multiplier, Urdhva-Triyagbhyam, arithmetic logic units, Power Consumption, Delay, speed.

1. INTRODUCTION

   Algorithms like Array multiplier, Booth multiplier, Bit serial multiplier, Carry save multiplier, Modified booth multiplier and Wallace multiplier can perform multiplication. In Array multiplier, combinational logic is used for multiplication of two binary numbers. This multiplier performs product of all bits at once due to which it is faster multiplier but it requires large number of gate which makes it not economical. In Carry save adder bits are processed one by one to add carry in adder. So it depends upon previous carry which increases its execution time as number of bits increases. In Wallace tree, three bit signals are passed to one bit full adder as input. Output of these inputs, sum is passed to the next state full adder which is at higher position. Because of high speed of operation layout of the Wallace tree multiplier is not possible. To overcome the drawback of these multipliers, Vedic Multiplier is proposed.[2,6] As the common digital signal processing algorithms spend most of their time multiplying, the processors spend a lot of chip area in order to make the multiplication as fast as possible. Hence a non-conventional yet very efficient Vedic mathematics is used for making a high performance multiplier. Vedic Mathematics deals mainly with various Vedic mathematical formulae and their applications for carrying out large arithmetical operations easily.

   1. Objective

      The objective of this project is to

      • Reduce the number of steps in multiplication process.

      • Reduce the computational delay.

      • Enhance the speed of addition by using MUX based adder.

      • Reduce power consumption.

      • Reduce memory utilization.

2. LITERATURE SURVEY

Y.Rama Lakshmanna, G.Challa Ram, Area efficient modified Vedic multiplier The paper describes the design of high speed Vedic multiplier that uses BEC(binary to excess converter) to add the partial products. The main advantage of BEC adder is, uses it uses less number of logic gates than the N-bit ripple carry adder which in turn reduces the power consumption and time delay. There is a comparision between array multiplier and Vedic multiplier. Implementation is done in Xilinx 12.2 on Spartan6 3E kit.

Saji.M.Antony, Dr.Rajeshwari Pandey, To Design High Speed Vedic Multiplier This paper describes the comparision of Vedic Multiplier with other conventional multipliers. The proposed design gives much less delay. Implementation is done in Xilinx ISE 14.7.

M.A.Sayyad, D.N.Kyatanavar, Optimization for Addition Partial Products in Vedic Multiplier In this paper they have designed Vedic Multiplier by using different adders like ripple carry adder and carry look ahead adder and compared it with array multiplier. Power Dissipation has been reduced. Implementation is done in Xilinx ISE 13.1.

Kush Kumar, Vishesh Tyagi, A State-of-the-Art Study on multipliers: Advancement and Comparision In this journal there is a comparision between various multipliers like array multiplier, booth multiplier, Vedic Multiplier. Considering the parameters like speed, area, power consumption they have shown that Vedic Multiplier.

3 VEDIC MULTIPLIER

The proposed Vedic Multiplier is based on the Vedic Multiplier formulae (sutras). These Sutras have been traditionally used for the multiplication of two numbers in the decimal number system. Apply the same ideas to the binary number system to make the proposed algorithm compatible with the digital hardware. Vedic multiplication based on some algorithm, is discussed below:

1. Urdhva Tiryabhyam sutra

   The multiplier is based on an algorithm Urdhva Triyakbhyam (Vertical & Crosswise) of ancient Indian Vedic Mathematics. Urdhva Triyakbhyam Sutra is a general multiplication formula applicable to all cases of multiplication. It literally means Vertically and crosswise. It is based on a novel concept through which the generation of all partial products can be done and then, concurrent addition of these partial products can be done. Thus parallelism in generation of partial products and their summation is obtained using Urdhva Triyakbhyam. The algorithm can be generalized for n x n bi number. Since the partial products and their sums are calculated in parallel, the multiplier is independent of the clock frequency of the processor. Thus the multiplier will require the same amount of time to calculate the product and hence is independent of the clock frequency. The net advantage is that it reduces the need of microprocessors to operate at increasingly high clock frequencies. While a higher clock frequency generally results in increased processing power, its disadvantage is that it also increases power dissipation which results in higher device operating temperatures.

2. Vertically and crosswise technique

   Figure 3.1: Vertically and Crosswise Technique

   Step1: S0 = A0*B0

   Step2: S1 = A1*B0+A0*B1

   Step3: S2 = A2*B0+A0*B2+A1*B1

   Step4: S3 = A3*B0+A0*B3+A2*B1+A1*B2

   Step5: S4 = A3*B1+A1*B3+A2*B2

   Step6: S5 = A3*B2+A2*B3

   Step7: S6 = A3*B

   Finally the output is: S0S1S2S3S4S5S6

   As the number of steps are reduced in UT algorithm compared to Array Multiplier, this technique will be more efficient for designing a Multiplier.

   Now we will see how this algorithm can be used for binary numbers. For example,

   Figure 3.2: Using Urdhva Tiryakbhyam for Binary numbers

3. 4 x 4 Vedic Multiplier

Here, rather than following sequential expansion, the expansion tree has been changed to Wallace tree resemble the other the same, along these lines diminishing the degrees of expansion to 2, rather than 3. Here, two lower bits of q0 pass legitimately to yield, while the upper bits of q0 are taken care of into expansion tree. The bits being fed to addition tree can be further illustrated by the diagram in fig3.3.

Fig. 3.3: 4×4 blck partial products addition process.

Fig 3.4: 4×4 Vedic Multiplier

Fig.3.5. Schematic of 4×4 Vedic Multiplier

Fig.3.6 Waveforms of 4×4 Vedic Multiplier Setup.

Fig.3.7 Output waveforms of 4×4 Vedic Multiplier.

4. CONCLUSIONS

4×4 Vedic Multiplier is implemented using modified full adder. Multiplexer is used in modified full adder for efficient addition. As the number of steps in multiplication is reduced, delay is reduced and hence speed of the multiplier increases. Vedic Algorithm like Urdhav Tiryagbhyam is best suited for high speed application and where area is a major constraint. MUX based adder is best suited for less power consumption applications.

DSP application modules like MAC require multipliers which can work on real time data at high clock rates which can be achieved with Vedic Multipliers. Ease of implementation of the design shows that complex modules for DSP and image processing can be simplified using Vedic algorithm.

REFERENCES

1. Paras Gulati,Harsh Yadav, Manoj Kumar Taleja Implementation of an efficient Multiplier Using the Vedic Multiplication Algorithm 2016 International Conference on Computing, Communication and Automation (ICCCA) IEEE (2016).

2. M. Akila, C. Gowribala, S. Maflin Shaby Implementation of High Speed Vedic Multiplier using Modified Adder 2016 International Conference on Communication and Signal Processing, IEEE(April 2016).

3. Srikanth S, Banu IT, Priya GV, Usha G. [2016] March). Low power array multiplier using modified full adder. In Engineering and Technology (ICETECH), 2016 IEEE International Conference on (pp. 1041-1044). IEEE

4. Kush Kumar1, Vishesh Tyagi1, Himanshu Kukreja1, Shaveta Thakral1, and Mohit Verma A State-Of-The-Art Study On Multipliers: Advancement And Comparison, ISSN: 0976-3104, ISSUE: Engineering and Technology IIOA3 Journal.

5. Josmin Thomas, R. Pushpangadan, Jinesh S Comparative Study of Performance Vedic Multiplier on the Basis of Adders Used 2015 International WIF Conference on Electrical and Computer Engineering (WIECON-ECE) IEEE (December 2015).

6. Srivastava P, Vishant V, Singh RK, Nagaria RK. [2013] Design and implementation of high performance array multipliers for digital circuits. In Engineering and Systems (SCES), 2013 Students Conference on (pp. 1-5). IEEE.

7. Yang ZY, Xiao JQ. [2011] the design and simulation of array multiplier improved with pipeline techniques. In Electronic and Mechanical Engineering and Information Technology (EMEIT), 2011 International Conference on Vol. 8: 43264329. IEEE

8. Sahoo SK, Shekhar C. [2011] Delay optimized array multiplier for signal and image processing. In Image Information Processing (ICIIP), 2011 International Conference on (pp. 14). IEEE.

BIOGRAPHIES

Dr. Savita Sonoli completed B.E (E&CE), from BVBCET, Hubli, M.Tech (IE) from NITK, Surathkal, and Ph.D (Embedded Systems) from SK University, Ananthpur. She has 24 years of teaching experience, 18 years of research and 19 years of administration. At Present, working as Vice Principal & Head, E&CE Dept., RYMEC, Ballari. Worked as VTU

BOE and LIC member.BOS member of E&CE Dept., SVCE, Bangalore, and as a Guest faculty. Member for professional bodies, IEEE, ISTE, IEI, ISOI, IAENG, ISCA, ISRASE & IEAE. Organized

and attended many Workshops, FDPs and STTPs. Guided 12 M.Tech students, currently guiding 5 research scholars under VTU and one scholar is awarded with Ph.D under VTU. Published 42 Technical papers in National \ International journals \ Conference having good impact factor and indexed in Scopus and Google scholar and received awards for best paper. Reviewer for National / International journals and worked as a chair person for conferences. Received funds from VTU, KSTA, KSCST for projects and for organizing national level workshops and symposium. Received award for Best Projects guided. Major ongoing project funded is VGST, GOK for 20 Lacs. Visited Michigan & Wisconsin states of USA as GSE team member and Alumni meet at Dallas, USA.

Sahana Desai, completed BE(ECE)in Ballari Institute of Technology and Management.I am currently pursuing M tech in Digital communication and Networking at RYMEC,Bellary. Interested in communication

domain and have done projects regarding home automation using microcontrollers and also in VLSI.