/////////////////////////////////////////////////////////////////////////                                                             ////////  Linear Feedback Shift Register                             ////////                                                             ////////  Author: Richard Herveille                                  ////////          richard@asics.ws                                   ////////          www.asics.ws                                       ////////                                                             /////////////////////////////////////////////////////////////////////////////                                                             //////// Copyright (C) 2001, 2002 Richard Herveille                  ////////                          richard@asics.ws                   ////////                                                             //////// This source file may be used and distributed without        //////// restriction provided that this copyright statement is not   //////// removed from the file and that any derivative work contains //////// the original copyright notice and the associated disclaimer.////////                                                             ////////     THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     //////// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   //////// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   //////// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      //////// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         //////// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    //////// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   //////// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        //////// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  //////// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  //////// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  //////// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         //////// POSSIBILITY OF SUCH DAMAGE.                                 ////////                                                             /////////////////////////////////////////////////////////////////////////////  CVS Log////  $Id: lfsr.v,v 1.1 2002/10/29 20:05:40 rherveille Exp $////  $Date: 2002/10/29 20:05:40 $//  $Revision: 1.1 $//  $Author: rherveille $//  $Locker:  $//  $State: Exp $//// Change History://               $Log: lfsr.v,v $//               Revision 1.1  2002/10/29 20:05:40  rherveille//               Initial release Huffman Encoder/Decoder testbench//`include "timescale.v"module lfsr (clk, ena, nReset, rst, q);	//	// parameters	//	parameter [3:0] TAPS   = 8;                // number of flip-flops in LFSR	//	// inputs & outputs	//	input clk;                                 // master clock	input ena;                                 // clock enable	input nReset;                              // asynchronous active low reset	input rst;                                 // synchronous active high reset	output [TAPS:1] q;                         // LFSR output	reg [TAPS:1] q;	//	// Module body	//	function lsb;	   input [TAPS-1:0] q;	   case (TAPS)	       2: lsb = ~q[0];	       3: lsb = q[3] ^ q[2];	       4: lsb = q[4] ^ q[3];	       5: lsb = q[5] ^ q[3];	       6: lsb = q[6] ^ q[5];	       7: lsb = q[7] ^ q[6];	       8: lsb = q[8] ^ q[6] ^ q[5] ^ q[4];	       9: lsb = q[9] ^ q[5];	      10: lsb = q[10] ^ q[7];	      11: lsb = q[11] ^ q[9];	      12: lsb = q[12] ^ q[6] ^ q[4] ^ q[1];	      13: lsb = q[13] ^ q[4] ^ q[3] ^ q[1];	      14: lsb = q[14] ^ q[5] ^ q[3] ^ q[1];	      15: lsb = q[15] ^ q[14];	      16: lsb = q[16] ^ q[15] ^ q[13] ^ q[4];	   endcase	endfunction	always @(posedge clk or negedge nReset)	  if (~nReset)	q <= #1 0;	  else if (rst)	q <= #1 0;	  else if (ena)	q <= #1 {q[TAPS-1:1], lsb(q)};endmodule