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VARDHAMAN COLLEGE OF ENGINEERING(AUTONOMOUS)Shamshabad-501218, HyderabadDEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERINGFOUR YEAR B.TECH VIII SEMESTER (2014-2015)COMPONENT-IIENHANCED LOW POWER HIGH SPEED ADDER FOR ERROR TOLERANT APPLICATIONSE.P.VanethaUNDER THE GUIDANCE OFBYNAVYA REDDY I(479)NAGA RAJESH G(478)BHARATH T(464)SAI VISHAL M(492)Assistant Professor14/20/2015CONTENTS IntroductionETAIIETAIIMTerminologyBlock DiagramSimulation ResultApplications20 April 2015ERROR TOLERANT ADDER IV2INTRODUCTIONA circuit of an application is said to be an error-tolerant(ET) if:

It contains defects that may cause internal and external errors the system incorporating this circuit produces acceptable results.It can be seen as a new trade-off parameter besides power and speed.20 April 2015ERROR TOLERANT ADDER IV3Error-Tolerant Adder(ETAII)ETAII was proposed for ET applications such that an N-bit adder is divided into M (M>1) which is different from normal addition.

Advantages: The speed performance of the adder is improved and the time taken to produce the result is also much smaller than that of its sum generator.

Drawbacks: The performance of accuracy degrades for large input operands.

20 April 2015ERROR TOLERANT ADDER IV4

Block Diagram Of ETAII20 April 2015ERROR TOLERANT ADDER IV520 April 2015ERROR TOLERANT ADDER IV6module fa(a,b,cin,s,cout);input a,b,cin;output s,cout;assign s=a^b^cin;assign cout=a&b|b&cin|cin&a;endmoduleFULL ADDER (1-BIT)20 April 2015ERROR TOLERANT ADDER IV7RIPPLE CARRY ADDER (4-BIT)module RCA(a,b,cin,s,cout);input [3:0]a,b;input cin;output [3:0]s;output cout;wire [2:0]w;fa m1(a[0],b[0],cin,s[0],w[0]);fa m2(a[1],b[1],w[0],s[1],w[1]);fa m3(a[2],b[2],w[1],s[2],w[2]);fa m4(a[3],b[3],w[2],s[3],cout);endmodule20 April 2015ERROR TOLERANT ADDER IV8ETA-II (32 BITS)module FA32(a,b,cin,sum,cout);input [31:0]a,b;input cin;output [31:0]sum;output cout;wire [6:0]c;RCA r1(a[3:0],b[3:0],cin,sum[3:0],c[0]);RCA r2(a[7:4],b[7:4],c[0],sum[7:4],c[1]);RCA r3(a[11:8],b[11:8],c[1],sum[11:8],c[2]);RCA r4(a[15:12],b[15:12],c[2],sum[15:12],c[3]);RCA r5(a[19:16],b[19:16],c[3],sum[19:16],c[4]);RCA r6(a[23:20],b[23:20],c[4],sum[23:20],c[5]);RCA r7(a[27:24],b[27:24],c[5],sum[27:24],c[6]);RCA r8(a[31:28],b[31:28],c[6],sum[31:28],cout);endmoduleError-Tolerant Adder Modified(ETAIIM)ETAIIM was then implemented to improve on the accuracy of ETAII.Advantage: Improved accuracy.Drawback: Circuit delay, with a 63.5% increment as compared to ETAII.

20 April 2015ERROR TOLERANT ADDER IV9Block Diagram Of ETAIIM

20 April 2015ERROR TOLERANT ADDER IV1020 April 2015ERROR TOLERANT ADDER IV11module cla4(a,b,cin,cout);input[3:0] a,b;input cin;output cout;wire[3:0] g,p;wire[3:0] z;wire [2:0] c;

xor x1 (p[0],a[0],b[0]);and x2 (g[0],a[0],b[0]);xor x3 (p[1],a[1],b[1]);and x4 (g[1],a[1],b[1]);xor x5 (p[2],a[2],b[2]);and x6 (g[2],a[2],b[2]);xor x7 (p[3],a[3],b[3]);and x8 (g[3],a[3],b[3]);and x9 (z[0],p[0],cin);or x10 (c[0],g[0],z[0]);and x11 (z[1],p[1],c[0]);or x12 (c[1],g[1],z[1]);and x13 (z[2],p[2],c[1]);or x14 (c[2],g[2],z[2]);and x15 (z[3],p[3],c[2]);or x16 (cout,g[3],z[3]);endmodule

CARRY LOOK AHEAD ADDER20 April 2015ERROR TOLERANT ADDER IV12module fa(a,b,cin,s,cout);input a,b,cin;output s,cout;assign s=a^b^cin;assign cout=a&b|b&cin|cin&a;endmoduleFULL ADDER (1-BIT)20 April 2015ERROR TOLERANT ADDER IV13RIPPLE CARRY ADDER (4-BIT)module RCA(a,b,cin,s,cout);input [3:0]a,b;input cin;output [3:0]s;output cout;wire [2:0]w;fa m1(a[0],b[0],cin,s[0],w[0]);fa m2(a[1],b[1],w[0],s[1],w[1]);fa m3(a[2],b[2],w[1],s[2],w[2]);fa m4(a[3],b[3],w[2],s[3],cout);endmodule20 April 2015ERROR TOLERANT ADDER IV14RIPPLE CARRY ADDER MODIFIED (4-BIT)module RCA_M(a,b,cin,s);input [3:0]a,b;input cin;output [3:0]s;wire [3:0]w;fa m1(a[0],b[0],cin,s[0],w[0]);fa m2(a[1],b[1],w[0],s[1],w[1]);fa m3(a[2],b[2],w[1],s[2],w[2]);fa m4(a[3],b[3],w[2],s[3],w[3]);endmodule20 April 2015ERROR TOLERANT ADDER IV15module ETA2m(a,b,cin,s,cout);input [31:0]a,b;input cin;output [31:0]s;output cout;wire [6:0]c;cla4 C1(a[3:0],b[3:0],cin,c[0]);cla4 C2(a[7:4],b[7:4],cin,c[1]);cla4 C3(a[11:8],b[11:8],cin,c[2]);cla4 C4(a[15:12],b[15:12],cin,c[3]);cla4 C5(a[19:16],b[19:16],cin,c[4]);cla4 C6(a[23:20],b[23:20],c[4],c[5]);cla4 C7(a[27:24],b[27:24],c[5],c[6]);RCAM r1(a[3:0],b[3:0],cin,s[3:0]);RCAM r2(a[7:4],b[7:4],c[0],s[7:4]);RCAM r3(a[11:8],b[11:8],c[1],s[11:8]);RCAM r4(a[15:12],b[15:12],c[2],s[15:12]);RCAM r5(a[19:16],b[19:16],c[3],s[19:16]);RCAM r6(a[23:20],b[23:20],c[4],s[23:20]);RCAM r7(a[27:24],b[27:24],c[5],s[27:24]);RCA r8(a[31:28],b[31:28],c[6],s[31:28],cout);endmodule

ETA-IIM (32-BIT)20 April 2015ERROR TOLERANT ADDER IV16

SIMULATION RESULTTERMINOLOGYOverall error (OE): OE =| Rc Re | Accuracy (ACC): Accuracy of an adder indicates how correct the output is for a particular input. It is defined as:

20 April 2015ERROR TOLERANT ADDER IV17Minimum acceptable accuracy (MAA): The result obtained whose accuracy is higher than the minimum acceptable accuracy (threshold) is called acceptable result.Acceptance probability (AP) :Acceptance probability is the probability that the accuracy of an adder is higher than the minimum acceptable accuracy.

20 April 2015ERROR TOLERANT ADDER IV18FFT transforms the time-domain information of the sound into frequency domain and IFFT transform it back from frequency domain to time domain.

Widely used in multimedia systems such as sound and image processing.

Sound signal can be stored as an array.

APPLICATIONS20 April 2015ERROR TOLERANT ADDER IV1920 April 2015ERROR TOLERANT ADDER IV201.Melvin A. Breuer, Lets think analog, in Proc. of the IEEE Computer Society Annual Symposium on VLSI, 2005.

2. M. A. Breuer and H. Zhu, An Illustrated Methodology for Analysis of Error Tolerance, IEEE Design and Test Magazine, pp. 168177.REFERENCES20 April 2015ERROR TOLERANT ADDER IV21THANK YOU