Merge commit 'v3.3.0' into upstream

[debian/gnuradio] / gr-sounder / src / fpga / lib / lfsr_constants.v

diff --git a/gr-sounder/src/fpga/lib/lfsr_constants.v b/gr-sounder/src/fpga/lib/lfsr_constants.v
new file mode 100644 (file)
index 0000000..e23ed66
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+++ b/gr-sounder/src/fpga/lib/lfsr_constants.v
@@ -0,0 +1,63 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2007 Corgan Enterprises LLC
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+module lfsr_constants(clk_i,rst_i,degree_i,mask_o,len_o);
+   input             clk_i;
+   input             rst_i;
+   input      [4:0]  degree_i;
+   output reg [15:0] mask_o;
+   output reg [16:0] len_o;
+
+   integer len;
+   
+   always @(posedge clk_i)
+     if (rst_i)
+       begin
+         len_o <= #5 17'b0;
+         mask_o <= #5 16'b0;
+       end
+     else
+       begin
+         len_o <= #5 ((1 << degree_i) << 1)-3;
+         
+         case (degree_i)
+           5'd00: mask_o <= #5 16'h0000;
+           5'd01: mask_o <= #5 16'h0001;
+           5'd02: mask_o <= #5 16'h0003;
+           5'd03: mask_o <= #5 16'h0005;
+           5'd04: mask_o <= #5 16'h0009;
+           5'd05: mask_o <= #5 16'h0012;
+           5'd06: mask_o <= #5 16'h0021;
+           5'd07: mask_o <= #5 16'h0041;
+           5'd08: mask_o <= #5 16'h008E;
+           5'd09: mask_o <= #5 16'h0108;
+           5'd10: mask_o <= #5 16'h0204;
+           5'd11: mask_o <= #5 16'h0402;
+           5'd12: mask_o <= #5 16'h0829;
+           5'd13: mask_o <= #5 16'h100D;
+           5'd14: mask_o <= #5 16'h2015;
+           5'd15: mask_o <= #5 16'h4001;
+           5'd16: mask_o <= #5 16'h8016;
+           default: mask_o <= #5 16'h0000;
+          endcase // case(degree_i)
+       end // else: !if(rst_i)
+
+endmodule // lfsr_constants