**Structural Model : Half Adder**

module half_adder(

output S,C,

input A,B

);

xor(S,A,B);

and(C,A,B);

endmodule

**Structural**

**Model : Full Adder**

module full_adder(

output S,Cout,

input A,B,Cin

);

wire s1,c1,c2;

half_adder HA1(s1,c1,A,B);

half_adder HA2(S,c2,s1,Cin);

or OG1(Cout,c1,c2);

endmodule

**Structural**

**Model : 4 Bit Ripple Carry Adder**

module ripple_adder_4bit(

output [3:0] Sum,

output Cout,

input [3:0] A,B,

input Cin

);

wire c1,c2,c3;

full_adder FA1(Sum[0],c1,A[0],B[0],Cin),

FA2(Sum[1],c2,A[1],B[1],c1),

FA3(Sum[2],c3,A[2],B[2],c2),

FA4(Sum[3],Cout,A[3],B[3],c3);

endmodule

**Test Bench : 4 Bit Ripple Carry Adder**

module test_ripple_adder_4bit;

// Inputs

reg [3:0] A;

reg [3:0] B;

reg Cin;

// Outputs

wire [3:0] Sum;

wire Cout;

// Instantiate the Unit Under Test (UUT)

ripple_adder_4bit uut (

.Sum(Sum),

.Cout(Cout),

.A(A),

.B(B),

.Cin(Cin)

);

initial begin

// Initialize Inputs

A = 0;

B = 0;

Cin = 0;

// Wait 100 ns for global reset to finish

#100;

// Add stimulus here

A=4'b0001;B=4'b0000;Cin=1'b0;

#10 A=4'b1010;B=4'b0011;Cin=1'b0;

#10 A=4'b1101;B=4'b1010;Cin=1'b1;

end

initial begin

$monitor("time=",$time,, "A=%b B=%b Cin=%b : Sum=%b Cout=%b",A,B,Cin,Sum,Cout);

end

endmodule

Is "Sum" from the top level 4bit_Ripple_Carry_Adder module supposed to be "set equal" to anything?

ReplyDelete"4bit_Ripple_Carry_Adder" is a hardware module which has two 3-bit input buses(A,B), an input line(Cin), a 3-bit output bus(Sum) and an output line (Cout).

DeleteYes, obviously Sum is supposed to be connected to the module which requires the sum of A and B.

hey jaya...i need one favour i am implementing this paper for my project http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5337888 but in this they have used radix 2 but i am going to use radix 4 and they have implemented in CMOS i am going to do gate level implementation .....yes i need verilog code and test bench for radix 4 modified booth algorith 8 bit , then i need code for hybrid carry save adder tree ....i this paper i couldnt understand the process in that CSA and accumulator can u explain it to me pl...i have to complete this project in one month...pl help me wth this project ..

DeleteThis comment has been removed by the author.

ReplyDeleteCould you elaborate the errors. (Error description, line no etc...)

DeleteThanks for replying! i got it figured out. It wasn't a problem with your code.

DeleteThanks for replying! i got it figured out. It wasn't a problem with your code.

ReplyDeleteGood day! Do you use some particular tricks to attract more followers this portal? Can't wait to hear from you.

ReplyDeletethanks alot

ReplyDeleteHi there, can i have the verilog for "ripple-carry adder and 4-bit block carry skip adder". Please help me, mail me to puvan5555@gmail.com

ReplyDeleteThis comment has been removed by the author.

ReplyDeleteThis comment has been removed by the author.

ReplyDeleteHi jeya .Can you please write verilog code for square root carrt select adder?

ReplyDeletecan u help me to design cordic algorithm for butterfly unit

ReplyDeletethis verilog code is much shorter than vhdl counterpart for ripple adder

ReplyDeleteVHDL code for Ripple Carry Adder using Structural Model

Hey i want to know that HA (half adder) is a predefined codes in verilog ??

ReplyDeletecan i get the verilog code for square root carry select adder 16 bit

ReplyDeleteI'm looking for ways on how to create a 8-bit hybrid CLA-CPA adder out of two 4-bit CLA adders. Could you provide me with code on how to do so in Verilog? Thank you Jeya.

ReplyDeletei need 16-bit ripple carry adder testbench verilog code....plz help me

ReplyDeletecan anyone please help me with verilog and testbench code for ripple carry adder using reversible logic gates?

ReplyDeletemail id: prashant12031995@gmail.com

hi! can you please do me a favour? i have a project on booth multiplier using ripple carry adder. and i can't find the verilog code for it.

ReplyDeletemail id: afroseroohi2@gmail.com

hey when i used this code it got compiled correctly but when i am simulating it,it says

ReplyDelete"Error: (vsim-3033) 714015-3-70P.v(30): Instantiation of 'FA3' failed. The design unit was not found.

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what should i do?