// Copyright 2007 Altera Corporation. All rights reserved. // Altera products are protected under numerous U.S. and foreign patents, // maskwork rights, copyrights and other intellectual property laws. // // This reference design file, and your use thereof, is subject to and governed // by the terms and conditions of the applicable Altera Reference Design // License Agreement (either as signed by you or found at www.altera.com). By // using this reference design file, you indicate your acceptance of such terms // and conditions between you and Altera Corporation. In the event that you do // not agree with such terms and conditions, you may not use the reference // design file and please promptly destroy any copies you have made. // // This reference design file is being provided on an "as-is" basis and as an // accommodation and therefore all warranties, representations or guarantees of // any kind (whether express, implied or statutory) including, without // limitation, warranties of merchantability, non-infringement, or fitness for // a particular purpose, are specifically disclaimed. By making this reference // design file available, Altera expressly does not recommend, suggest or // require that this reference design file be used in combination with any // other product not provided by Altera. ///////////////////////////////////////////////////////////////////////////// // baeckler - 02-15-2006 // recursive sorting network implementation of rotate right // for Stratix II module rotate_internal (din,dout,distance); `include "log2.inc" parameter WIDTH = 16; parameter DIST_WIDTH = log2(WIDTH-1); parameter GENERIC = 0; localparam MAX_D = 1 << DIST_WIDTH; // The shifting range described by // the distance. // this subdesign does not allow shifting beyond the data width // e.g. rotating an 8 bit value 100 steps. initial begin #10 if (MAX_D > WIDTH) begin $display ("Error - Rotation by distance greater than data width not supported"); $stop(); end end input [WIDTH-1:0] din; output [WIDTH-1:0] dout; input [DIST_WIDTH-1:0] distance; wire [WIDTH-1:0] dout; wire [2*WIDTH-1:0] double_din = {din,din}; genvar i; generate if (GENERIC) begin assign dout = double_din >> distance; end else begin wire [WIDTH-1:0] layer; if (DIST_WIDTH == 0) begin // degenerate case assign dout = din; end else if (DIST_WIDTH == 1) begin // knock out the last distance line for (i=0;i