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//////////////////////////////////////////////////////////////////////

////                                                              ////

////  OR1K_startup                                                ////

////                                                              ////

////  This file is part of the OR1K startup IP core project       ////

////  http://www.opencores.org/                                   ////

////                                                              ////

////  Author(s):                                                  ////

////      - Michael Unneback (unneback@opencores.org)             ////

////                                                              ////

////  All additional information is avaliable in the Readme.txt   ////

////  file.                                                       ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

////                                                              ////

//// Copyright (C) 2009 Authors                                   ////

////                                                              ////

//// 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 source file 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 2.1 of the License, or (at your option) any   ////

//// later version.                                               ////

////                                                              ////

//// This source 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 this source; if not, download it   ////

//// from http://www.opencores.org/lgpl.shtml                     ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

module OR1K_startup

  (

    input [6:2]       wb_adr_i,

    input             wb_stb_i,

    input             wb_cyc_i,

    output reg [31:0] wb_dat_o,

    output reg        wb_ack_o,

    input             wb_clk,

    input             wb_rst

   );

   reg [3:0]           counter;

   wire [7:0]          do;

   parameter [31:0] NOP = 32'h15000000;

   always @ (posedge wb_clk or posedge wb_rst)

     if (wb_rst)

       counter <= 4'd0;

     else

       if (!wb_cyc_i)

         counter <= 4'd0;

       else if (wb_cyc_i & wb_stb_i & !wb_ack_o)

         counter <= counter + 4'd1;

   always @ (posedge wb_clk or posedge wb_rst)

     if (wb_rst)

       wb_ack_o <= 1'b0;

     else

       wb_ack_o <= (counter == 4'd15);

   always @ (posedge wb_clk or posedge wb_rst)

     if (wb_rst)

       wb_dat_o <= NOP;

     else

       case (counter)

         4'd15: wb_dat_o[31:24] <= do;

         4'd11: wb_dat_o[23:16] <= do;

         4'd7 : wb_dat_o[15: 8] <= do;

         4'd3 : wb_dat_o[ 7: 0] <= do;

       endcase

   flash flash0

     (

      .CLK  (counter[1] ^ counter[0]),

      .ADDR ({wb_adr_i,counter[3:2]}),

      .DOUT (do)

      );

endmodule