VLSI experiments II

SIMULATION AND IMPLEMENTATION OF LOGIC GATES
AIM:

To simulate and implement the logic gates using XC3S400 FPGA kit

APPARATUS REQUIRED

1. PC with XILINX ISE 9.1i

2. XC3S400 FPGA kit

PROGRAM

module logicgates(a,b,y1,y2,y3,y4,y5,y6,y7,y8);

input a,b;

output y1,y2,y3,4y,y5,y6,y7,y8;

buf (y1,a);

not (y2, b);

or (y3,a,b);

and (y5,a,b);

nand (y6,a,b);

xor (y7,a,b);

xnor (y8,a,b);

end module

RESULT:

Thus the logic gates have been simulated and implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF HALF ADDER AND FULL ADDER
AIM:

To simulate and implement half adder and full adder using XC3S400 FPGA kit

APPARATUS REQUIRED:

1. PC with XILINX ISE 9.1 i

2. XC3S400 FPGA kit

PROGRAM:

HALF ADDER:

module halfadder (a,b,sum,carry);

input a,b;

xor (sum,a,b);

and (carry,a,b);

end module

FULL ADDER:

module fulladder (a,b,c,sum,carry);

input a,b,c;

output sum,carry;

assign sum=a^b^c;

assign carry=(a&b)|(b&c)|(c&a);

end module

RESULT:

Thus the half adder and the full adder were simulated and implemented using XC3S400
FPGA kit.

SIMULATION AND IMPLEMENTATION OF HALF SUBTRACTOR AND FULL
SUBTRACTOR
AIM:

To simulate and implement half subtractor and full subtractor using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

HALF SUBTRACTOR

module halfsubtractor (x,y,difference,borrow);

input x,y;

output difference, borrow;

assign difference = (x^y);

assign borrow = (~x&y);

end module

FULL SUBTRACTOR

module fulsubtractor (x,y,bin,d,bout);

input x,y,bin;

output d,bout;

assign d = x^y^bin;

assign bout = (~x&y)|(~x&bin)|(y&bin);

end module

RESULT:

Thus the half subtractor and full subtractor were implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF PARALLEL ADDER

AIM:

To simulate and implement parallel adder using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module paralleladder (a,b,cin,sum,cout);

input [3:0] a,b;

input cin;

output [3:0] sum;

assign {cout,sum} = a+b+Cin;

end module

RESULT:

Thus the parallel adder was simulated and implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF PARALLEL SUBTRACTOR

AIM:

To simulate and implement parallel subtractor using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module parallelsubtractor (x,y,bin,difference,bout);

input [3:0] x,y;

input bin;

output bout;

assign {bout,difference} = x-y-bin;

end module

RESULT:

Thus the parallel subtractor was simulated and implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF CARRY LOOK-AHEAD ADDER

AIM:

To simulate and implement carry look-ahead adder using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module CLAadder (a,b,cin,sum,cout);

input [3:0] a,b;

input cin;

output [3:0] sum;

output cout;

wire p0,p1,p2,p3,g1,g2,g3;

wire c1,c2,c3,c4;

assign p0 = (a[0]^b[0]),

p1 = (a[1]^b[1]),

p2 = (a[2]^b[2]),

p3 = (a[3]^b[3]);

assign g0 = (a[0] & b[0]),

g1 = (a[1] & b[1]),

g2 = (a[2] & b[2]),

g3 = (a[3] & b[3]),

assign c0 = cin,

c1 = g0 | (p0 & cin),

c3 = g2 | (p2 & g1)|(p2&p1&g0)|(p2&p1&p0&cin),

c2 = g1 | (p0 & g0)|(p1&p0&cin),

c4 = g3|(p3&g2)|(p3&p2&g1)|(p3&p2&p1&g0)|(p3&p2&p1&p0&cin);

assign sum[0] = p0^c0,

sum[1] = p1^c1,

sum [2] = p2^c2,

sum [3] = p3^c3,

assign cout = c4

end module

RESULT:

Thus the carry look-ahead adder was simulated and implemented using XC3S400 FPGA
kit.

SIMULATION AND IMPLEMENTATION OF CMOS GATES

AIM:

To simulate and implement CMOS gates using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

CMOS INVERTER:

module my_inv (input);

input in;

output out;

supply1 pwr;

supply0 gnd;

pmos (out, pwr, in);

nmos (out, gnd, in);

end module

CMOS NOT GATE:

module my_nor (a,b,out);

input a,b;

output out;

wire c;

supply1 pwr;

supply0 gnd;

pmos (c, pwr, b);

pmos (out, c, a);

nmos (out,gnd,a);

nmos (out,gnd,b);

end module

CMOS NAND GATE:

module my_nand (a,b,out);

input a,b;

output out;

wire c;

supply1 pwr;

supply0 gnd;

pmos (out, pwr, a);

pmos (out, pwr, b);

nmos (out,c,a);

nmos (c,gnd,b);

end module

CMOS XOR GATE:

module my_xor (a,b,out);

input a,b;

output out;

wire e,f,g;

supply1 pwr;

supply0 gnd;

assign c=~a;

assign d=~b;

pmos (e,pwr,c);

pmos (e,pwr,d);

pmos (out,e,a);

pmos (out,e,b);

nmos (f,gnd,b);

nmos (out,g,c);

nmos (g,gnd,d);

end module

RESULT:

Thus CMOS gates were simulated and implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF PARALLEL ADDER AND SUBTRACTOR
AIM:

To simulate and implement parallel adder and subtractor using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module paralleladd_sub (a3,a2,a1,a0,b3,b2,b1,b0,m,sum3,sum2,sum1,sum0,cout);

input a3,a2,a1,a0 ;

input b3,b2,b1,b0,m;

output sum3,sum2,sum1,sum0,cout;

wire cin,c1,c2,d0,d1,d2,d3;

assign cin =m;

assign d0 = a0^m,

d1 = a1^m,

d2 = a2^m,

d3 = a3^m;

full_add ff0(b0,d0,cin,sum0,c0);

full_add ff1(b1,d1,c0,sum1,c1);



end module

module full_add (a,b,c,sum,carry);

input a,b,c;

output sum, carry;

assign sum = a^b^c;

assign carry = (a&b)|(b&c)|(c&a);

end module

RESULT:

Thus the parallel subtractor was simulated and implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF 8:3 ENCODER AND 3:8 DECODER
AIM:

To simulate and implement 8:3 encoder and 3:8 decoder using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

8:3 ENCODER:

module encoder8_3 (d0,d1,d2,d3,d4,d5,d6,d7,a,b,c);

input d0,d1,d2,d3,d4,d5,d6,d7;

output a,b,c;

or (a,d4,d5,d6,d7);

or (b,d2,d3,d6,d7);

out (c,d,d3,d5,d7):

end module

3:8 DECODER:

module decoder3_8 (a,b,c,d0,d1,d2,d3,d4,d5,d6,d7);

input a,b,c;

output d0,d1,d2,d3,d4,d5,d6,d7;

assign d0 = (~a&~b&~c),

d1 = (~a&~b&c),

d2 = (~a&b&~c),

d3 = (~a&b&c),

d4 = (a&~b&~c),

d5 = (a&~ b&c),

d6 = (a&b&~c),

d7 = (a&b&c);

end module

RESULT:

Thus the 8:3 encoder and 3:8 decoder was simulated and implemented using XC3S400
FPGA kit.

SIMULATION AND IMPLEMENTATION OF 1:8 DEMULTIPLEXER AND 4:1
MULTIPLEXER
AIM:

To simulate and implement of 1:8 demultiplexer and 4:1 multiplexer using XC3S400
FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

1:8 DEMULTIPLEXER:

module demux1_8 (i,so,s1,s2,d0,d1,d2,d3,d4,d5,d6,d7);

input I,so,s1,s2;

output d0,d1,d2,d3,d4,d5,d6,d7;

assign d0 = (i&~s2&~s1&~s0),

d1 = (i&~s2&~s1&s0),

d2 = (i&~s2&s1&~s0),

d3 = (i&~s2&s1&s0),

d4 = (i&s2&~s1&~s0),

d5 = (i&s2&~ s1&s0),

d6 = (i&s2&s1&~s0),

d7 = (i&s2&s1&s0);

end module

4:1 MULTIPLEXER:

module mux4_1 (i0,i1,i2,i3,s0,s1,out);

input i0,i1,i2,i3,s0,s1;

output out;

assign out = (i0&~s1&~s0)| (i1&~s1&~s0)| (i2&s1&~s0)| (i3&s1&s0);

end module

RESULT:

Thus the 8:3 encoder and 3:8 decoder was simulated and implemented using XC3S400
FPGA kit.

SIMULATION AND IMPLEMENTATION OF 8 BIT MULTIPLEXER

AIM:

To simulate and implement 8 bit multiplexer using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module multiplexer_8_bit (a,b,c);

input [7:0] a;

input [7:0] b;

output [15:0] c;

assign c[15:0] = a[7:0] * b[7:0];

end module

RESULT:

Thus the 8 bit multiplexer was simulated and implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF FLIP FLOPS

AIM:

To simulate and implement flip flops using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

SR FLIP FLOP:

module sr_ff (s,r,clk,q,qbar);

input s,r,clk;

output q,qbar;

reg q,qbar;

always @ (posedge clk)

begin

case ({s,r})

2’b00 : q = q;

2’b01 : q = 1’b0;

2’b10 : q = 1’b1;

2’b11 : q = 1’bx;

end case

qbar = ~q;

end

end module

D FLIP FLOP:

module d_ff (d,clk,reset,q);

input d,clk,reset;

output q;

reg q;

always @ (posedge reset or negedge clk)

if (reset)

q = 1’b0;

else

q=d;

end module

T FLIP FLOP:

module t_ff (t,clk,reset,q);

input t,clk,reset;

output q;

wire w;

assign w = t^q;

d_ff dff1(w,clk,reset,q);

end module


input d,clk,reset;

output q;

reg q;


if (reset)

q = 1’b0;

else

q=d;

end module

JK FLIP FLOP:

module jk_ff (j,k,clk,reset,q);

input j,k,clk,reset;

output q;

wire w;

assign w = (j^~q)|(~k&q);

d_ff dff1(w,clk,reset,q);

end module


input d,clk,reset;

output q;

reg q;


if (reset)

q = 1’b0;

else

q=d;

end module

RESULT:

Thus the flip flops were simulated and implemented using XC3S400 FPGA kit.

SIMULATION AND IMPLEMENTATION OF SYNCHRONOUS UP DOWN COUNTER

AIM:

To simulate and implement synchronous up down counter using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module updowncounter (up_down,clk,reset,count);

input [1:0] up,down;

input clk, reset;

output [2:0] count;

reg [2:0] count;

always @ (posedge clk or negedge reset)

if ( reset = = 1) count <= 3’b000;

else

if (up_down = = 2’b00 || up_down = = 2’b11)

count <= count;

else

if (up_down = = 2’b01)

count <= count+1;

else

if (up_down = = 2’b10)

count <= count-1;

end module

RESULT:

Thus the synchronous up down counter was simulated and implemented using XC3S400
FPGA kit.

SIMULATION AND IMPLEMENTATION OF UNIVERSAL SHIFT REGISTER

AIM:

To simulate and implement universal shift register using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module unishift_reg (s1,s0,PIin,LFin, RTin,clk,reset,q3,q2,q1,q0);

input s1,s0;

input LFin, RTin;

input clk, reset;

input [3:0] PIin;

output q3,q2,q1,q0;

reg q3,q2,q1,q0;

always @ (posedge clk or negedge reset)

if ( reset)

{q3,q2,q1,q0} = 4’b0000;

else

case ({s1,s0})

2’b00 : {q3,q2,q1,q0} = {q3,q2,q1,q0);

2’b01 : {q3,q2,q1,q0} = {RTin,q3,q2,q1);

2’b10 : {q3,q2,q1,q0} = {q2,q1,q0,LFin);

2’b11 : {q3,q2,q1,q0} = PIin;

end case

end module

RESULT:

Thus the universal shift register was simulated and implemented using XC3S400 FPGA
kit

SIMULATION AND IMPLEMENTATION OF SERIAL ADDER

AIM:

To simulate and implement serial adder using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module serial_adder (count2,count1,count0,clk,a0,a1,a2,a3,a4,a5,a6,a7, a8,result,add);

input count2,count1,count0;

input clk;

input a0,a1,a2,a3,a4,a5,a6,a7, a8;

output [3:0] add,result;

reg [3:0] result,add;


case ({count2,count1,count0})

3’b0000 : begin

add = a0+a1;

end

3’b001 : begin

add = add + a2;

end

3’b010 : begin

add = add + a3;

end

3’b011 : begin

add = add + a4;

end

3’b100 : begin

add = add + a5;

end

3’b101 : begin

add = add + a6;

end

3’b110 : begin

add = add + a7;

end

3’b111 : begin

add = add + a8;

end

end case

end module

RESULT:

Thus the serial adder was simulated and implemented using XC3S400 FPGA kit

SIMULATION AND IMPLEMENTATION OF TRAFFIC LIGHT CONTROLLER

AIM:

To simulate and implement traffic light controller using XC3S400 FPGA kit.

APPARATUS REQUIRED:


2. XC3S400 FPGA kit

PROGRAM:

module tlc (state2,state1,state0,clk,r0,y0,g0,p0,r1,y1,g1,p1);

input state2,state1,state0;

input clk;

input r0,y0,g0,p0,r1,y1,g1,p1;

reg r0,y0,g0,p0,r1,y1,g1,p1;


case ({state2,state1,state0})

3’b000 : begin

r0 =1;

y0 =0;

g0 =0;

p0 =1;

r1 =1;

y1 =0;

g1 =0;

p1 =1;

end

3’b001 : begin

r0 =0;

y0 =1;

g0 =0;

p0 =1;

r1 =1;

y1 =0;

g1 =0;

p1 =1;

end

3’b010 : begin

r0 =0;

y0 =0;

g0 =1;

p0 =0;

r1 =1;

y1 =0;

g1 =0;

p1 =0;

end

3’b011 : begin

r0 =0;

y0 =1;

g0 =0;

p0 =0;

r1 =0;

y1 =1;

g1 =0;

p1 =0;

end

3’b100 : begin

r0 =1;

y0 =0;

g0 =0;

p0 =0;

r1 =0;

y1 =0;

g1 =1;

p1 =0;

end

3’b101 : begin

r0 =1;

y0 =0;

g0 =0;

p0 =0;

r1 =0;

y1 =1;

g1 =0;

p1 =0;

end

default : begin

r0 =0;

y0 =0;

g0 =0;

p0 =0;

r1 =0;

y1 =0;

g1 =0;

p1 =0;

end

end case

end module

RESULT:

Thus the traffic light controller was simulated and implemented using XC3S400 FPGA kit

VLSI experiments II

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VLSI experiments II