Test Code Tags - Please Disregard

[bigdogguru]

16 to 1 MUX

/**********************************************************************
* Date: Aug. 16, 2006
* File: Mux_16_to_1.v (440 Examples)
*
* Structural of a 16 to 1 MUX (Sixteen 1-bit inputs) that is built
* using two 8-to-1 muxes that feed a 2-to-1 mux.
*
* Note the use of a continuous assignment statement for implementing
* the combinational logic, avoiding the necessity of a "register"
* data type for output Y.
**********************************************************************/
//*********************************************************
module mux_16to1(Y, In, sel);
//*********************************************************
output Y;
input [15:0] In;
input [3:0] sel;
wire lo8, hi8, out1;
// Instantiate the 8-to-1 muxes and the 2-to-1 mux
mux_8to1 mux_lo (lo8, In[7:0], sel[2:0]);
mux_8to1 mux_hi (hi8, In[15:8], sel[2:0]);
mux_2to1 mux_out (out1, lo8, hi8, sel[3]);
// equate the wire out of the 2-to-1 with
// the actual output (Y) of the 16-to-1 mux
assign Y = out1;
endmodule

Testbench:

`timescale 1ns / 100ps
/**********************************************************************
* Date: Aug. 28, 1999
* File: Test_Mux_16_to_1.v (440 Examples)
*
* Testbench to generate some stimulus and display the results for the
* Mux 16 to 1 module -- with sixteen 1-bit inputs
**********************************************************************/
//*********************************************************
module Test_mux_16to1;
//*********************************************************
wire MuxOut;
reg [15:0] In;
reg [3:0] sel;
// Instantiate the MUX (named DUT {device under test})
mux_16to1 DUT(MuxOut, In, sel);
initial begin
$timeformat(-9, 1, " ns", 6);
$monitor("At t=%t sel=%b In=%b_%b MuxOut=%b",$time,sel,In[15:8],In[7:0],MuxOut);
In = 16'b1100_0011_1011_0100; // time = 0
sel = 4'b0000;
#10;
sel = 4'b0001; // time = 10
#10;
sel = 4'b0010; // time = 20
#10;
sel = 4'b0011; // time = 30
#10;
In = 16'b1100_0011_1011_1111;
sel = 4'b0100; // time = 40
#10;
sel = 4'b0101; // time = 50
#10;
sel = 4'b0110; // time = 60
#10;
sel = 4'b0111; // time = 70
#10;
In = 16'b1100_0011_1111_1111; // time = 80
sel = 4'b1000;
#10;
sel = 4'b1001; // time = 90
#10;
sel = 4'b1010; // time = 100
#10;
sel = 4'b1011; // time = 110
#10;
In = 16'b1100_1111_1111_1111;
sel = 4'b1100; // time = 120
#10;
sel = 4'b1101; // time = 130
#10;
sel = 4'b1110; // time = 140
#10;
sel = 4'b1111; // time = 150
#5;
$finish;
end
endmodule