Subversion Repositories pci

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

////                                                              ////

////  File name "conf_cyc_addr_dec.v"                             ////

////                                                              ////

////  This file is part of the "PCI bridge" project               ////

////  http://www.opencores.org/cores/pci/                         ////

////                                                              ////

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

////      - Miha Dolenc (mihad@opencores.org)                     ////

////                                                              ////

////  All additional information is avaliable in the README       ////

////  file.                                                       ////

////                                                              ////

////                                                              ////

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

////                                                              ////

//// Copyright (C) 2001 Miha Dolenc, mihad@opencores.org          ////

////                                                              ////

//// 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                     ////

////                                                              ////

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

//

// CVS Revision History

//

// $Log: not supported by cvs2svn $

//

// module is a simple decoder which decodes device num field of configuration address

// for type0 configuration cycles. If type 1 configuration cycle is

// initiated then address goes through unchanged

`include "constants.v"

module CONF_CYC_ADDR_DEC

(

    ccyc_addr_in,

    ccyc_addr_out

) ;

input   [31:0]  ccyc_addr_in ;

output  [31:0]  ccyc_addr_out ;

reg     [31:11]  ccyc_addr_31_11 ;

// lower 11 address lines are alweys going through unchanged

assign ccyc_addr_out = {ccyc_addr_31_11, ccyc_addr_in[10:0]} ;

// configuration cycle type indicator

wire ccyc_type = ccyc_addr_in[0] ;

always@(ccyc_addr_in or ccyc_type)

begin

    if (ccyc_type)

        // type 1 cycle - address goes through unchanged

        ccyc_addr_31_11 = ccyc_addr_in[31:11] ;

    else

    begin

        // type 0 conf. cycle - decode device number field to appropriate value

        case (ccyc_addr_in[15:11])

            5'h00:ccyc_addr_31_11 = 21'h00_0001 ;

            5'h01:ccyc_addr_31_11 = 21'h00_0002 ;

            5'h02:ccyc_addr_31_11 = 21'h00_0004 ;

            5'h03:ccyc_addr_31_11 = 21'h00_0008 ;

            5'h04:ccyc_addr_31_11 = 21'h00_0010 ;

            5'h05:ccyc_addr_31_11 = 21'h00_0020 ;

            5'h06:ccyc_addr_31_11 = 21'h00_0040 ;

            5'h07:ccyc_addr_31_11 = 21'h00_0080 ;

            5'h08:ccyc_addr_31_11 = 21'h00_0100 ;

            5'h09:ccyc_addr_31_11 = 21'h00_0200 ;

            5'h0A:ccyc_addr_31_11 = 21'h00_0400 ;

            5'h0B:ccyc_addr_31_11 = 21'h00_0800 ;

            5'h0C:ccyc_addr_31_11 = 21'h00_1000 ;

            5'h0D:ccyc_addr_31_11 = 21'h00_2000 ;

            5'h0E:ccyc_addr_31_11 = 21'h00_4000 ;

            5'h0F:ccyc_addr_31_11 = 21'h00_8000 ;

            5'h10:ccyc_addr_31_11 = 21'h01_0000 ;

            5'h11:ccyc_addr_31_11 = 21'h02_0000 ;

            5'h12:ccyc_addr_31_11 = 21'h04_0000 ;

            5'h13:ccyc_addr_31_11 = 21'h08_0000 ;

            5'h14:ccyc_addr_31_11 = 21'h10_0000 ;

            default: ccyc_addr_31_11 = 21'h00_0000 ;

        endcase

    end

end

endmodule