Sequence detector Verilog Code , using Behavioral modeling

1. Experiment No: 10
Name: Shyamveer Singh
Regno: 11205816
Roll No:B­54
Aim: ​To implement the sequence detector using behavioral modeling.
Theory: ​A sequence detector accepts as input a string of bits: either 0 or 1. Its output
goes to 1 when a target sequence has been detected. There are two basic types:
overlap and non­overlap. In an sequence detector that allows overlap, the final bits of
one sequence can be the start of another sequence. Our example will be a 11011
sequence detector. It raises an output of 1 when the last 5 binary bits received are
11011. At this point, a detector with overlap will allow the last two 1 bits to serve at
the first of a next sequence. By example we show the difference between the two
detectors. Suppose an input string 11011011011.
Sequence detector state transition diagram:
For 1011
module seqdetector(clk,reset,inp,state,z);
input clk,reset,inp;
output reg [2:0]state;
output reg z;
parameter s0=2'b00,
s1=2'b01,
s2=2'b10,
s3=2'b11;
always@(clk or reset)

2. if (reset)
begin
state<=s0;
end
else
case(state)
s0:begin
if(inp)
begin
state<=s1;
z<=0;
end
else
begin
state<=s0;
z<=0;
end
end
s1: begin if(inp)
begin
state<=s2;
z<=0;
end
else
begin
state<=s0;
z<=0;
end
end
s2:begin if(inp)
begin
state<=s3;
z<=0;
end
else
begin
state<=s1;
z<=0;
end
end
s3:begin if(inp)
begin
state<=s0;
z<=0;
end
else
begin

3. state<=s1;
z<=1;
end
end
endcase
endmodule

5.
module seqdetecteor(clk,reset,i,state,z);
input clk,reset,i;
output state,z;
reg state,z;
parameter s0=0,s1=1,s2=2,s3=3;
always@(posedge clk or posedge reset)
if(reset)
begin
state<=s0;
end
else
case(state)
s0:begin if(i)
begin
state<=s0;

6. z<=0;
end
else
begin
state<=s1;
z<=0;
end
end
s1:begin if(i)
begin
state<=s2;
z<=0;
end
else
begin
state<=s1;
z<=0;
end
end
s2:begin if(i)
begin
state<=s3;
z<=0;
end
else
begin
state<=s1;
z<=0;
end
end
s3:begin if(i)
begin
state<=s0;
z<=1;
end
else
begin
state<=s1;

7. z<=0;
end
end
endcase
endmodule
Learning Outcome:
After performing this experiment we learn how to detect a particular sequence step wise , we also learn
the various commands of Xilines software.