Subversion Repositories ethernet_tri_mode

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

////                                                              ////

////  MAC_rx_add_chk.v                                            ////

////                                                              ////

////  This file is part of the Ethernet IP core project           ////

////  http://www.opencores.org/projects.cgi/wr_en/ethernet_tri_mode/////

////                                                              ////

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

////      - Jon Gao (gaojon@yahoo.com)                            ////

////                                                              ////

////                                                              ////

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

////                                                              ////

//// Copyright (C) 2001 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                     ////

////                                                              ////

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

//                                                                    

// CVS Revision History                                               

//                                                                    

// $Log: not supported by cvs2svn $

// Revision 1.2  2005/12/16 06:44:17  Administrator

// replaced tab with space.

// passed 9.6k length frame test.

//

// Revision 1.1.1.1  2005/12/13 01:51:45  Administrator

// no message

//                                           

module MAC_rx_add_chk (

Reset               ,

Clk                 ,

Init                ,

data                ,

MAC_add_en          ,

MAC_rx_add_chk_err  ,

//From CPU                                         

MAC_rx_add_chk_en   ,

MAC_add_prom_data   ,

MAC_add_prom_add    ,

MAC_add_prom_wr

);

input           Reset               ;

input           Clk                 ;

input           Init                ;

input   [7:0]   data                ;

input           MAC_add_en          ;

output          MAC_rx_add_chk_err  ;

                //From CPU

input           MAC_rx_add_chk_en   ;

input   [7:0]   MAC_add_prom_data   ;

input   [2:0]   MAC_add_prom_add    ;

input           MAC_add_prom_wr     ;

//******************************************************************************   

//internal signals                                                              

//******************************************************************************

reg [2:0]   addr_rd;

wire[2:0]   addr_wr;

wire[7:0]   din;

wire[7:0]   dout;

wire        wr_en;

reg         MAC_rx_add_chk_err;

reg         MAC_add_prom_wr_dl1;

reg         MAC_add_prom_wr_dl2;

reg [7:0]   data_dl1                ;

reg         MAC_add_en_dl1          ;

//******************************************************************************   

//write data from cpu to prom                                                              

//******************************************************************************

always @ (posedge Clk or posedge Reset)

    if (Reset)

        begin

        data_dl1            <=0;

        MAC_add_en_dl1      <=0;

        end

    else

        begin

        data_dl1            <=data;

        MAC_add_en_dl1      <=MAC_add_en;

        end

always @ (posedge Clk or posedge Reset)

    if (Reset)

        begin

        MAC_add_prom_wr_dl1     <=0;

        MAC_add_prom_wr_dl2     <=0;

        end

    else

        begin

        MAC_add_prom_wr_dl1     <=MAC_add_prom_wr;

        MAC_add_prom_wr_dl2     <=MAC_add_prom_wr_dl1;

        end

assign wr_en      =MAC_add_prom_wr_dl1&!MAC_add_prom_wr_dl2;

assign addr_wr    =MAC_add_prom_add;

assign din        =MAC_add_prom_data;

//******************************************************************************   

//mac add verify                                                             

//******************************************************************************

always @ (posedge Clk or posedge Reset)

    if (Reset)

        addr_rd       <=0;

    else if (Init)

        addr_rd       <=0;

    else if (MAC_add_en)

        addr_rd       <=addr_rd + 1;

always @ (posedge Clk or posedge Reset)

    if (Reset)

        MAC_rx_add_chk_err  <=0;

    else if (Init)

        MAC_rx_add_chk_err  <=0;

    else if (MAC_rx_add_chk_en&&MAC_add_en_dl1&&dout!=data_dl1)

        MAC_rx_add_chk_err  <=1;

//******************************************************************************   

//a port for read ,b port for write .

//******************************************************************************     

duram #(8,3,"M512","DUAL_PORT") U_duram(

.data_a         (din       ),

.wren_a         (wr_en        ),

.address_a      (addr_wr      ),

.address_b      (addr_rd      ),

.clock_a        (Clk        ),

.clock_b        (Clk        ),

.q_b            (dout      ));

endmodule