eth_ocm/eth_rxaddrcheck.v

   1 //////////////////////////////////////////////////////////////////////
   2 ////                                                              ////
   3 ////  eth_rxaddrcheck.v                                           ////
   4 ////                                                              ////
   5 ////  This file is part of the Ethernet IP core project           ////
   6 ////  http://www.opencores.org/cores/ethmac/                      ////
   7 ////                                                              ////
   8 ////  Author(s):                                                  ////
   9 ////      - Bill Dittenhofer (billditt@aol.com)                   ////
  10 ////                                                              ////
  11 ////  All additional information is avaliable in the Readme.txt   ////
  12 ////  file.                                                       ////
  13 ////                                                              ////
  14 //////////////////////////////////////////////////////////////////////
  15 ////                                                              ////
  16 //// Copyright (C) 2001 Authors                                   ////
  17 ////                                                              ////
  18 //// This source file may be used and distributed without         ////
  19 //// restriction provided that this copyright statement is not    ////
  20 //// removed from the file and that any derivative work contains  ////
  21 //// the original copyright notice and the associated disclaimer. ////
  22 ////                                                              ////
  23 //// This source file is free software; you can redistribute it   ////
  24 //// and/or modify it under the terms of the GNU Lesser General   ////
  25 //// Public License as published by the Free Software Foundation; ////
  26 //// either version 2.1 of the License, or (at your option) any   ////
  27 //// later version.                                               ////
  28 ////                                                              ////
  29 //// This source is distributed in the hope that it will be       ////
  30 //// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
  31 //// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
  32 //// PURPOSE.  See the GNU Lesser General Public License for more ////
  33 //// details.                                                     ////
  34 ////                                                              ////
  35 //// You should have received a copy of the GNU Lesser General    ////
  36 //// Public License along with this source; if not, download it   ////
  37 //// from http://www.opencores.org/lgpl.shtml                     ////
  38 ////                                                              ////
  39 //////////////////////////////////////////////////////////////////////
  40 //
  41 // CVS Revision History
  42 //
  43 // $Log: eth_rxaddrcheck.v,v $
  44 // Revision 1.9  2002/11/22 01:57:06  mohor
  45 // Rx Flow control fixed. CF flag added to the RX buffer descriptor. RxAbort
  46 // synchronized.
  47 //
  48 // Revision 1.8  2002/11/19 17:34:52  mohor
  49 // AddressMiss status is connecting to the Rx BD. AddressMiss is identifying
  50 // that a frame was received because of the promiscous mode.
  51 //
  52 // Revision 1.7  2002/09/04 18:41:06  mohor
  53 // Bug when last byte of destination address was not checked fixed.
  54 //
  55 // Revision 1.6  2002/03/20 15:14:11  mohor
  56 // When in promiscous mode some frames were not received correctly. Fixed.
  57 //
  58 // Revision 1.5  2002/03/02 21:06:32  mohor
  59 // Log info was missing.
  60 //
  61 //
  62 // Revision 1.1  2002/02/08 12:51:54  ditt
  63 // Initial release of the ethernet addresscheck module.
  64 //
  65 //
  66 //
  67 //
  68 //
  69
  70
  71 `include "timescale.v"
  72
  73
  74 module eth_rxaddrcheck(MRxClk,  Reset, RxData, Broadcast ,r_Bro ,r_Pro,
  75                        ByteCntEq2, ByteCntEq3, ByteCntEq4, ByteCntEq5,
  76                        ByteCntEq6, ByteCntEq7, HASH0, HASH1,
  77                        CrcHash,    CrcHashGood, StateData, RxEndFrm,
  78                        Multicast, MAC, RxAbort, AddressMiss, PassAll,
  79                        ControlFrmAddressOK
  80                       );
  81
  82 parameter Tp = 1;
  83
  84   input        MRxClk;
  85   input        Reset;
  86   input [7:0]  RxData;
  87   input        Broadcast;
  88   input        r_Bro;
  89   input        r_Pro;
  90   input        ByteCntEq2;
  91   input        ByteCntEq3;
  92   input        ByteCntEq4;
  93   input        ByteCntEq5;
  94   input        ByteCntEq6;
  95   input        ByteCntEq7;
  96   input [31:0] HASH0;
  97   input [31:0] HASH1;
  98   input [5:0]  CrcHash;
  99   input        CrcHashGood;
 100   input        Multicast;
 101   input [47:0] MAC;
 102   input [1:0]  StateData;
 103   input        RxEndFrm;
 104   input        PassAll;
 105   input        ControlFrmAddressOK;
 106
 107   output       RxAbort;
 108   output       AddressMiss;
 109
 110  wire BroadcastOK;
 111  wire ByteCntEq2;
 112  wire ByteCntEq3;
 113  wire ByteCntEq4;
 114  wire ByteCntEq5;
 115  wire RxAddressInvalid;
 116  wire RxCheckEn;
 117  wire HashBit;
 118  wire [31:0] IntHash;
 119  reg [7:0]  ByteHash;
 120  reg MulticastOK;
 121  reg UnicastOK;
 122  reg RxAbort;
 123  reg AddressMiss;
 124
 125 assign RxAddressInvalid = ~(UnicastOK | BroadcastOK | MulticastOK | r_Pro);
 126
 127 assign BroadcastOK = Broadcast & ~r_Bro;
 128
 129 assign RxCheckEn   = | StateData;
 130
 131  // Address Error Reported at end of address cycle
 132  // RxAbort clears after one cycle
 133
 134 always @ (posedge MRxClk or posedge Reset)
 135 begin
 136   if(Reset)
 137     RxAbort <= #Tp 1'b0;
 138   else if(RxAddressInvalid & ByteCntEq7 & RxCheckEn)
 139     RxAbort <= #Tp 1'b1;
 140   else
 141     RxAbort <= #Tp 1'b0;
 142 end
 143
 144
 145 // This ff holds the "Address Miss" information that is written to the RX BD status.
 146 always @ (posedge MRxClk or posedge Reset)
 147 begin
 148   if(Reset)
 149     AddressMiss <= #Tp 1'b0;
 150   else if(ByteCntEq7 & RxCheckEn)
 151     AddressMiss <= #Tp (~(UnicastOK | BroadcastOK | MulticastOK | (PassAll & ControlFrmAddressOK)));
 152 end
 153
 154
 155 // Hash Address Check, Multicast
 156 always @ (posedge MRxClk or posedge Reset)
 157 begin
 158   if(Reset)
 159     MulticastOK <= #Tp 1'b0;
 160   else if(RxEndFrm | RxAbort)
 161     MulticastOK <= #Tp 1'b0;
 162   else if(CrcHashGood & Multicast)
 163     MulticastOK <= #Tp HashBit;
 164 end
 165
 166
 167 // Address Detection (unicast)
 168 // start with ByteCntEq2 due to delay of addres from RxData
 169 always @ (posedge MRxClk or posedge Reset)
 170 begin
 171   if(Reset)
 172     UnicastOK <= #Tp 1'b0;
 173   else
 174   if(RxCheckEn & ByteCntEq2)
 175     UnicastOK <= #Tp   RxData[7:0] == MAC[47:40];
 176   else
 177   if(RxCheckEn & ByteCntEq3)
 178     UnicastOK <= #Tp ( RxData[7:0] == MAC[39:32]) & UnicastOK;
 179   else
 180   if(RxCheckEn & ByteCntEq4)
 181     UnicastOK <= #Tp ( RxData[7:0] == MAC[31:24]) & UnicastOK;
 182   else
 183   if(RxCheckEn & ByteCntEq5)
 184     UnicastOK <= #Tp ( RxData[7:0] == MAC[23:16]) & UnicastOK;
 185   else
 186   if(RxCheckEn & ByteCntEq6)
 187     UnicastOK <= #Tp ( RxData[7:0] == MAC[15:8])  & UnicastOK;
 188   else
 189   if(RxCheckEn & ByteCntEq7)
 190     UnicastOK <= #Tp ( RxData[7:0] == MAC[7:0])   & UnicastOK;
 191   else
 192   if(RxEndFrm | RxAbort)
 193     UnicastOK <= #Tp 1'b0;
 194 end
 195
 196 assign IntHash = (CrcHash[5])? HASH1 : HASH0;
 197
 198 always@(CrcHash or IntHash)
 199 begin
 200   case(CrcHash[4:3])
 201     2'b00: ByteHash = IntHash[7:0];
 202     2'b01: ByteHash = IntHash[15:8];
 203     2'b10: ByteHash = IntHash[23:16];
 204     2'b11: ByteHash = IntHash[31:24];
 205   endcase
 206 end
 207
 208 assign HashBit = ByteHash[CrcHash[2:0]];
 209
 210
 211 endmodule