+++ /dev/null
-//////////////////////////////////////////////////////////////////////
-//// ////
-//// eth_clockgen.v ////
-//// ////
-//// This file is part of the Ethernet IP core project ////
-//// http://www.opencores.org/projects/ethmac/ ////
-//// ////
-//// Author(s): ////
-//// - Igor Mohor (igorM@opencores.org) ////
-//// ////
-//// All additional information is avaliable in the Readme.txt ////
-//// file. ////
-//// ////
-//////////////////////////////////////////////////////////////////////
-//// ////
-//// 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: eth_clockgen.v,v $
-// Revision 1.2 2005/12/13 12:54:49 maverickist
-// first simulation passed
-//
-// Revision 1.1.1.1 2005/12/13 01:51:45 Administrator
-// no message
-//
-// Revision 1.2 2005/04/27 15:58:45 Administrator
-// no message
-//
-// Revision 1.1.1.1 2004/12/15 06:38:54 Administrator
-// no message
-//
-// Revision 1.3 2002/01/23 10:28:16 mohor
-// Link in the header changed.
-//
-// Revision 1.2 2001/10/19 08:43:51 mohor
-// eth_timescale.v changed to timescale.v This is done because of the
-// simulation of the few cores in a one joined project.
-//
-// Revision 1.1 2001/08/06 14:44:29 mohor
-// A define FPGA added to select between Artisan RAM (for ASIC) and Block Ram (For Virtex).
-// Include files fixed to contain no path.
-// File names and module names changed ta have a eth_ prologue in the name.
-// File eth_timescale.v is used to define timescale
-// All pin names on the top module are changed to contain _I, _O or _OE at the end.
-// Bidirectional signal MDIO is changed to three signals (Mdc_O, Mdi_I, Mdo_O
-// and Mdo_OE. The bidirectional signal must be created on the top level. This
-// is done due to the ASIC tools.
-//
-// Revision 1.1 2001/07/30 21:23:42 mohor
-// Directory structure changed. Files checked and joind together.
-//
-// Revision 1.3 2001/06/01 22:28:55 mohor
-// This files (MIIM) are fully working. They were thoroughly tested. The testbench is not updated.
-//
-//
-
-module eth_clockgen(Clk, Reset, Divider, MdcEn, MdcEn_n, Mdc);
-
- parameter Tp=1;
-
- input Clk; // Input clock (Host clock)
- input Reset; // Reset signal
- input [7:0] Divider; // Divider (input clock will be divided by the Divider[7:0])
-
- output Mdc; // Output clock
- output MdcEn; // Enable signal is asserted for one Clk period before Mdc rises.
- output MdcEn_n; // Enable signal is asserted for one Clk period before Mdc falls.
-
- reg Mdc;
- reg [7:0] Counter;
-
- wire CountEq0;
- wire [7:0] CounterPreset;
- wire [7:0] TempDivider;
-
-
- assign TempDivider[7:0] = (Divider[7:0]<2)? 8'h02 : Divider[7:0]; // If smaller than 2
- assign CounterPreset[7:0] = (TempDivider[7:0]>>1) -1; // We are counting half of period
-
-
- // Counter counts half period
- always @ (posedge Clk or posedge Reset)
- begin
- if(Reset)
- Counter[7:0] <= #Tp 8'h1;
- else
- begin
- if(CountEq0)
- begin
- Counter[7:0] <= #Tp CounterPreset[7:0];
- end
- else
- Counter[7:0] <= #Tp Counter - 8'h1;
- end
- end
-
-
- // Mdc is asserted every other half period
- always @ (posedge Clk or posedge Reset)
- begin
- if(Reset)
- Mdc <= #Tp 1'b0;
- else
- begin
- if(CountEq0)
- Mdc <= #Tp ~Mdc;
- end
- end
-
-
- assign CountEq0 = Counter == 8'h0;
- assign MdcEn = CountEq0 & ~Mdc;
- assign MdcEn_n = CountEq0 & Mdc;
-
-endmodule // eth_clockgen
-
-
-
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