Subversion Repositories plb2wbbridge

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----                                                              ----

----  PLB2WB-Bridge                                               ----

----                                                              ----

----  This file is part of the PLB-to-WB-Bridge project           ----

----  http://opencores.org/project,plb2wbbridge                   ----

----                                                              ----

----  Description                                                 ----

----  Implementation of a PLB-to-WB-Bridge according to           ----

----  PLB-to-WB Bridge specification document.                    ----

----                                                              ----

----  To Do:                                                      ----

----   Nothing                                                    ----

----                                                              ----

----  Author(s):                                                  ----

----      - Christian Haettich                                    ----

----        feddischson@opencores.org                             ----

----                                                              ----

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---- Copyright (C) 2010 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                     ----

----                                                              ----

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library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use ieee.std_logic_unsigned.all;

package plb2wb_pkg is

   --

   --    The range of the address pipeline depth

   constant PIPE_D_MIN        : integer := 2;

   constant PIPE_D_MAX        : integer := 512;

   --     The range of the wishbone-data-bus width

   constant WB_DWIDTH_MIN     : integer := 32;

   constant WB_DWIDTH_MAX     : integer := 64;

   --     The range of the wishbone-address-bus width

   constant WB_AWIDTH_MIN     : integer := 32;

   constant WB_AWIDTH_MAX     : integer := 64;

   constant PLB_DWIDTH_MIN    : integer := 32;

   constant PLB_DWIDTH_MAX    : integer := 128;

   --

   -- error and reset info types and functions

   --

   constant STATUS2PLB_INFO_SIZE : integer := 3;

   constant STATUS2PLB_W_ERR     : integer := 0 ;

   constant STATUS2PLB_RST       : integer := 1 ;

   constant STATUS2PLB_IRQ       : integer := 2 ;

   --     The size data-size of the read/write buffer

   constant RBUF_DWIDTH32     : integer := 33;

   constant WBUF_DWIDTH32     : integer := 32;

   constant STATUS_CONTINUE  : std_logic_vector := "0";

   constant STATUS_ABORT     : std_logic_vector := "1";

   constant IRQ_INFO_SIZE  : integer := 32;

   function log2( steps : natural ) return natural;

end package plb2wb_pkg;

package body plb2wb_pkg is

   function log2( steps : natural ) return natural is

   variable size : natural := 1;

   begin

      while( 2**size < steps ) loop

         size := size + 1;

      end loop;

      return size;

   end log2;

end package body plb2wb_pkg;