Verilog Code of Decoder
3 to 8 Decoder Verilog Code
3 to 8 decoder Verilog Code using case statement
In this post we are going to share with you the Verilog code of decoder. As you know, a decoder asserts its output line based on the input. For a 3 : 8 decoder, total number of input lines is 3 and total number of output lines is 8. Based on the input, only one output line will be at logic high.
The Verilog code for 3:8 decoder with enable logic is given below.
3:8 Decoder Verilog Code
module decoder3_to_8( in,out, en);
input [2:0] in;
input en;
output [7:0] out;
reg [7:0] out;
always @( in or en)
begin
if (en)
begin
out=8'd0;
case (in)
3'b000: out[0]=1'b1;
3'b001: out[1]=1'b1;
3'b010: out[2]=1'b1;
3'b011: out[3]=1'b1;
3'b100: out[4]=1'b1;
3'b101: out[5]=1'b1;
3'b110: out[6]=1'b1;
3'b111: out[7]=1'b1;
default: out=8'd0;
endcase
end
else
out=8'd0;
end
endmodule
The Test bench for 3:8 Decoder is given below.
3:8 Decoder Test Bench
module decoder_tb;
wire [7:0] out;
reg en;
reg [2:0] in;
integer i;
decoder3_to_8 dut(in,out,en);
initial begin
$monitor( "en=%b, in=%d, out=%b ", en, in, out);
for ( i=0; i<16; i=i+1)
begin
{en,in} = i;
#1;
end
end
endmodule
The output is is given below.

If you have any query/suggestion please feel free to comment below the post.

Is there any alternative code
Yes there is 3 types of modelling in vhdl program
Namely 1.structural
2.dataflow level
3.behavioural
To write the program (・∀・)