Subversion Repositories tiny_tate_bilinear_pairing

/*

    Copyright 2012 Homer Hsing

    This file is part of Tiny Tate Bilinear Pairing Core.

    Tiny Tate Bilinear Pairing Core is free software: you can redistribute it and/or modify

    it under the terms of the GNU Lesser General Public License as published by

    the Free Software Foundation, either version 3 of the License, or

    (at your option) any later version.

    Tiny Tate Bilinear Pairing Core 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License

    along with Tiny Tate Bilinear Pairing Core.  If not, see http://www.gnu.org/licenses/lgpl.txt

*/

`define M     593         // M is the degree of the irreducible polynomial

`define WIDTH (2*`M-1)    // width for a GF(3^M) element

`define WIDTH_D0 1187

/*

 * the module of constants

 *

 * addr  out  effective

 *    1   0     1

 *    2   1     1

 *    4   +     1

 *    8   -     1

 *   16 cubic   1

 * other  0     0

 */

module const_ (clk, addr, out, effective);

    input clk;

    input [5:0] addr;

    output reg [`WIDTH_D0:0] out;

    output reg effective; // active high if out is effective

    always @ (posedge clk)

      begin

         effective <= 1;

         case (addr)

            1:  out <= 0;

            2:  out <= 1;

            4:  out <= {6'b000101, 1182'd0};

            8:  out <= {6'b001001, 1182'd0};

            16: out <= {6'b010101, 1182'd0};

            default:

               begin out <= 0; effective <= 0; end

         endcase

      end

endmodule