title: output is not continuously changing in 2x4 decoder testbench
body: <p>my 2x4 decoder code:</p>
  
  <pre><code>`timescale 1ns/100ps
  module decoder(in,out);
     input [1:0]in;
      output [3:0]out;
      reg [3:0]out;
  always@(in)
      begin
  
              case(in)
                  2'b00:out = 4'b0001;
                  2'b01:out = 4'b0010;
                  2'b10:out = 4'b0100;
                  2'b11:out = 4'b1000;
  
  
                  default:out = 4'b1111;
          endcase
  
  
          end
      endmodule
  </code></pre>
  
  <p>// **I have written behavior code for 2x4 decoder and test bench. What I am seeing in my output is only it is showing me the output at 11...which is 0011. I want to see output changing continuously whenever my input is changing.</p>
  
  <pre><code>can any body show my mistake ??**
  </code></pre>
  
  <p>piece of code//</p>
  
  <pre><code> `timescale 1ns / 100ps
  
  
          module decoder_t;
  
            reg [1:0]in;
            wire [3:0] out;
  
  
  
      decoder decoder1 ( .in(in),.out(out) );
  
      initial 
         begin
  
      #10 in=2'b00;
      #10 in=2'b01;
      #10 in=2'b10;
      #10 in=2'b11;
  
  
      #10 $stop;
  
         end
  
      endmodule
  </code></pre>