git.zerfleddert.de Git - raggedstone/blob - ethernet/source/pci/pci_conf_cyc_addr_dec.v

   1 //////////////////////////////////////////////////////////////////////
   2 ////                                                              ////
   3 ////  File name "conf_cyc_addr_dec.v"                             ////
   4 ////                                                              ////
   5 ////  This file is part of the "PCI bridge" project               ////
   6 ////  http://www.opencores.org/cores/pci/                         ////
   7 ////                                                              ////
   8 ////  Author(s):                                                  ////
   9 ////      - Miha Dolenc (mihad@opencores.org)                     ////
  10 ////                                                              ////
  11 ////  All additional information is avaliable in the README       ////
  12 ////  file.                                                       ////
  13 ////                                                              ////
  14 ////                                                              ////
  15 //////////////////////////////////////////////////////////////////////
  16 ////                                                              ////
  17 //// Copyright (C) 2001 Miha Dolenc, mihad@opencores.org          ////
  18 ////                                                              ////
  19 //// This source file may be used and distributed without         ////
  20 //// restriction provided that this copyright statement is not    ////
  21 //// removed from the file and that any derivative work contains  ////
  22 //// the original copyright notice and the associated disclaimer. ////
  23 ////                                                              ////
  24 //// This source file is free software; you can redistribute it   ////
  25 //// and/or modify it under the terms of the GNU Lesser General   ////
  26 //// Public License as published by the Free Software Foundation; ////
  27 //// either version 2.1 of the License, or (at your option) any   ////
  28 //// later version.                                               ////
  29 ////                                                              ////
  30 //// This source is distributed in the hope that it will be       ////
  31 //// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
  32 //// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
  33 //// PURPOSE.  See the GNU Lesser General Public License for more ////
  34 //// details.                                                     ////
  35 ////                                                              ////
  36 //// You should have received a copy of the GNU Lesser General    ////
  37 //// Public License along with this source; if not, download it   ////
  38 //// from http://www.opencores.org/lgpl.shtml                     ////
  39 ////                                                              ////
  40 //////////////////////////////////////////////////////////////////////
  41 //
  42 // CVS Revision History
  43 //
  44 // $Log: pci_conf_cyc_addr_dec.v,v $
  45 // Revision 1.1  2007-03-20 17:50:56  sithglan
  46 // add shit
  47 //
  48 // Revision 1.1  2003/01/27 16:49:31  mihad
  49 // Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed.
  50 //
  51 // Revision 1.3  2002/02/01 15:25:12  mihad
  52 // Repaired a few bugs, updated specification, added test bench files and design document
  53 //
  54 // Revision 1.2  2001/10/05 08:14:28  mihad
  55 // Updated all files with inclusion of timescale file for simulation purposes.
  56 //
  57 // Revision 1.1.1.1  2001/10/02 15:33:46  mihad
  58 // New project directory structure
  59 //
  60 //
  61
  62
  63 // module is a simple decoder which decodes device num field of configuration address
  64 // for type0 configuration cycles. If type 1 configuration cycle is
  65 // initiated then address goes through unchanged
  66
  67 // synopsys translate_off
  68 `include "timescale.v"
  69 // synopsys translate_on
  70
  71 module pci_conf_cyc_addr_dec
  72 (
  73     ccyc_addr_in,
  74     ccyc_addr_out
  75 ) ;
  76
  77 input   [31:0]  ccyc_addr_in ;
  78 output  [31:0]  ccyc_addr_out ;
  79 reg     [31:11]  ccyc_addr_31_11 ;
  80
  81 // lower 11 address lines are alweys going through unchanged
  82 assign ccyc_addr_out = {ccyc_addr_31_11, ccyc_addr_in[10:0]} ;
  83
  84 // configuration cycle type indicator
  85 wire ccyc_type = ccyc_addr_in[0] ;
  86
  87 always@(ccyc_addr_in or ccyc_type)
  88 begin
  89     if (ccyc_type)
  90         // type 1 cycle - address goes through unchanged
  91         ccyc_addr_31_11 = ccyc_addr_in[31:11] ;
  92     else
  93     begin
  94         // type 0 conf. cycle - decode device number field to appropriate value
  95         case (ccyc_addr_in[15:11])
  96             5'h00:ccyc_addr_31_11 = 21'h00_0001 ;
  97             5'h01:ccyc_addr_31_11 = 21'h00_0002 ;
  98             5'h02:ccyc_addr_31_11 = 21'h00_0004 ;
  99             5'h03:ccyc_addr_31_11 = 21'h00_0008 ;
 100             5'h04:ccyc_addr_31_11 = 21'h00_0010 ;
 101             5'h05:ccyc_addr_31_11 = 21'h00_0020 ;
 102             5'h06:ccyc_addr_31_11 = 21'h00_0040 ;
 103             5'h07:ccyc_addr_31_11 = 21'h00_0080 ;
 104             5'h08:ccyc_addr_31_11 = 21'h00_0100 ;
 105             5'h09:ccyc_addr_31_11 = 21'h00_0200 ;
 106             5'h0A:ccyc_addr_31_11 = 21'h00_0400 ;
 107             5'h0B:ccyc_addr_31_11 = 21'h00_0800 ;
 108             5'h0C:ccyc_addr_31_11 = 21'h00_1000 ;
 109             5'h0D:ccyc_addr_31_11 = 21'h00_2000 ;
 110             5'h0E:ccyc_addr_31_11 = 21'h00_4000 ;
 111             5'h0F:ccyc_addr_31_11 = 21'h00_8000 ;
 112             5'h10:ccyc_addr_31_11 = 21'h01_0000 ;
 113             5'h11:ccyc_addr_31_11 = 21'h02_0000 ;
 114             5'h12:ccyc_addr_31_11 = 21'h04_0000 ;
 115             5'h13:ccyc_addr_31_11 = 21'h08_0000 ;
 116             5'h14:ccyc_addr_31_11 = 21'h10_0000 ;
 117             default: ccyc_addr_31_11 = 21'h00_0000 ;
 118         endcase
 119     end
 120 end
 121
 122 endmodule