OpenFPGA/openfpga_flow/benchmarks/iwls2005/ethernet/rtl/eth_rxstatem.v

201 lines
7.2 KiB
Verilog

//////////////////////////////////////////////////////////////////////
//// ////
//// eth_rxstatem.v ////
//// ////
//// This file is part of the Ethernet IP core project ////
//// http://www.opencores.org/projects/ethmac/ ////
//// ////
//// Author(s): ////
//// - Igor Mohor (igorM@opencores.org) ////
//// - Novan Hartadi (novan@vlsi.itb.ac.id) ////
//// - Mahmud Galela (mgalela@vlsi.itb.ac.id) ////
//// ////
//// 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_rxstatem.v,v $
// Revision 1.6 2002/11/13 22:28:26 tadejm
// StartIdle state changed (not important the size of the packet).
// StartData1 activates only while ByteCnt is smaller than the MaxFrame.
//
// Revision 1.5 2002/01/23 10:28:16 mohor
// Link in the header changed.
//
// Revision 1.4 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 1.3 2001/10/18 12:07:11 mohor
// Status signals changed, Adress decoding changed, interrupt controller
// added.
//
// Revision 1.2 2001/09/11 14:17:00 mohor
// Few little NCSIM warnings fixed.
//
// 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 1.2 2001/07/03 12:55:41 mohor
// Minor changes because of the synthesys warnings.
//
//
// Revision 1.1 2001/06/27 21:26:19 mohor
// Initial release of the RxEthMAC module.
//
//
//
//
`include "timescale.v"
module eth_rxstatem (MRxClk, Reset, MRxDV, ByteCntEq0, ByteCntGreat2, Transmitting, MRxDEq5, MRxDEqD,
IFGCounterEq24, ByteCntMaxFrame, StateData, StateIdle, StatePreamble, StateSFD,
StateDrop
);
parameter Tp = 1;
input MRxClk;
input Reset;
input MRxDV;
input ByteCntEq0;
input ByteCntGreat2;
input MRxDEq5;
input Transmitting;
input MRxDEqD;
input IFGCounterEq24;
input ByteCntMaxFrame;
output [1:0] StateData;
output StateIdle;
output StateDrop;
output StatePreamble;
output StateSFD;
reg StateData0;
reg StateData1;
reg StateIdle;
reg StateDrop;
reg StatePreamble;
reg StateSFD;
wire StartIdle;
wire StartDrop;
wire StartData0;
wire StartData1;
wire StartPreamble;
wire StartSFD;
// Defining the next state
assign StartIdle = ~MRxDV & (StateDrop | StatePreamble | StateSFD | (|StateData));
assign StartPreamble = MRxDV & ~MRxDEq5 & (StateIdle & ~Transmitting);
assign StartSFD = MRxDV & MRxDEq5 & (StateIdle & ~Transmitting | StatePreamble);
assign StartData0 = MRxDV & (StateSFD & MRxDEqD & IFGCounterEq24 | StateData1);
assign StartData1 = MRxDV & StateData0 & (~ByteCntMaxFrame);
assign StartDrop = MRxDV & (StateIdle & Transmitting | StateSFD & ~IFGCounterEq24 & MRxDEqD
| StateData0 & ByteCntMaxFrame
);
// Rx State Machine
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
begin
StateIdle <= #Tp 1'b0;
StateDrop <= #Tp 1'b1;
StatePreamble <= #Tp 1'b0;
StateSFD <= #Tp 1'b0;
StateData0 <= #Tp 1'b0;
StateData1 <= #Tp 1'b0;
end
else
begin
if(StartPreamble | StartSFD | StartDrop)
StateIdle <= #Tp 1'b0;
else
if(StartIdle)
StateIdle <= #Tp 1'b1;
if(StartIdle)
StateDrop <= #Tp 1'b0;
else
if(StartDrop)
StateDrop <= #Tp 1'b1;
if(StartSFD | StartIdle | StartDrop)
StatePreamble <= #Tp 1'b0;
else
if(StartPreamble)
StatePreamble <= #Tp 1'b1;
if(StartPreamble | StartIdle | StartData0 | StartDrop)
StateSFD <= #Tp 1'b0;
else
if(StartSFD)
StateSFD <= #Tp 1'b1;
if(StartIdle | StartData1 | StartDrop)
StateData0 <= #Tp 1'b0;
else
if(StartData0)
StateData0 <= #Tp 1'b1;
if(StartIdle | StartData0 | StartDrop)
StateData1 <= #Tp 1'b0;
else
if(StartData1)
StateData1 <= #Tp 1'b1;
end
end
assign StateData[1:0] = {StateData1, StateData0};
endmodule