//////////////////////////////////////////////////////////////////////
//// ////
//// eth_rxethmac.v ////
//// ////
//// This file is part of the Ethernet IP core project ////
//// http://www.opencores.org/cores/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: not supported by cvs2svn $
// 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 1.1 2001/06/27 21:26:19 mohor
// Initial release of the RxEthMAC module.
//
//
//
//
//
`include "timescale.v"
module eth_rxethmac (MRxClk, MRxDV, MRxD, Reset, Transmitting, MaxFL, r_IFG, HugEn, DlyCrcEn,
RxData, RxValid, RxStartFrm, RxEndFrm, CrcHash, CrcHashGood, Broadcast,
Multicast, ByteCnt, ByteCntEq0, ByteCntGreat2, ByteCntMaxFrame,
CrcError, StateIdle, StatePreamble, StateSFD, StateData
);
parameter Tp = 1;
input MRxClk;
input MRxDV;
input [3:0] MRxD;
input Transmitting;
input HugEn;
input DlyCrcEn;
input [15:0] MaxFL;
input r_IFG;
input Reset;
output [7:0] RxData;
output RxValid;
output RxStartFrm;
output RxEndFrm;
output [8:0] CrcHash;
output CrcHashGood;
output Broadcast;
output Multicast;
output [15:0] ByteCnt;
output ByteCntEq0;
output ByteCntGreat2;
output ByteCntMaxFrame;
output CrcError;
output StateIdle;
output StatePreamble;
output StateSFD;
output [1:0] StateData;
reg [7:0] RxData;
reg RxValid;
reg RxStartFrm;
reg RxEndFrm;
reg Broadcast;
reg Multicast;
reg [8:0] CrcHash;
reg CrcHashGood;
reg DelayData;
reg [3:0] LatchedNibble;
reg [7:0] LatchedByte;
reg [7:0] RxData_d;
reg RxValid_d;
reg RxStartFrm_d;
reg RxEndFrm_d;
wire MRxDEqD;
wire MRxDEq5;
wire StateDrop;
wire ByteCntEq1;
wire ByteCntEq6;
wire ByteCntSmall7;
wire [31:0] Crc;
wire Enable_Crc;
wire Initialize_Crc;
wire [3:0] Data_Crc;
wire GenerateRxValid;
wire GenerateRxStartFrm;
wire GenerateRxEndFrm;
wire DribbleRxEndFrm;
wire [3:0] DlyCrcCnt;
assign MRxDEqD = MRxD == 4'hd;
assign MRxDEq5 = MRxD == 4'h5;
// Rx State Machine module
eth_rxstatem rxstatem1 (.MRxClk(MRxClk), .Reset(Reset), .MRxDV(MRxDV), .ByteCntEq0(ByteCntEq0),
.ByteCntGreat2(ByteCntGreat2), .Transmitting(Transmitting), .MRxDEq5(MRxDEq5),
.MRxDEqD(MRxDEqD), .IFGCounterEq24(IFGCounterEq24), .ByteCntMaxFrame(ByteCntMaxFrame),
.StateData(StateData), .StateIdle(StateIdle), .StatePreamble(StatePreamble),
.StateSFD(StateSFD), .StateDrop(StateDrop)
);
// Rx Counters module
eth_rxcounters rxcounters1 (.MRxClk(MRxClk), .Reset(Reset), .MRxDV(MRxDV), .StateIdle(StateIdle),
.StateSFD(StateSFD), .StateData(StateData), .StateDrop(StateDrop),
.StatePreamble(StatePreamble), .MRxDEqD(MRxDEqD), .DlyCrcEn(DlyCrcEn),
.DlyCrcCnt(DlyCrcCnt), .Transmitting(Transmitting), .MaxFL(MaxFL), .r_IFG(r_IFG),
.HugEn(HugEn), .IFGCounterEq24(IFGCounterEq24), .ByteCntEq0(ByteCntEq0),
.ByteCntEq1(ByteCntEq1), .ByteCntEq6(ByteCntEq6), .ByteCntGreat2(ByteCntGreat2),
.ByteCntSmall7(ByteCntSmall7), .ByteCntMaxFrame(ByteCntMaxFrame),
.ByteCnt(ByteCnt)
);
assign Enable_Crc = MRxDV & (|StateData & ~ByteCntMaxFrame);
assign Initialize_Crc = StateSFD | DlyCrcEn & (|DlyCrcCnt[3:0]) & DlyCrcCnt[3:0] < 4'h9;
assign Data_Crc[0] = MRxD[3];
assign Data_Crc[1] = MRxD[2];
assign Data_Crc[2] = MRxD[1];
assign Data_Crc[3] = MRxD[0];
// Connecting module Crc
eth_crc crcrx (.Clk(MRxClk), .Reset(Reset), .Data(Data_Crc), .Enable(Enable_Crc), .Initialize(Initialize_Crc),
.Crc(Crc), .CrcError(CrcError)
);
// Latching CRC for use in the hash table
always @ (posedge MRxClk)
begin
CrcHashGood <= #Tp StateData[0] & ByteCntEq6;
end
always @ (posedge MRxClk)
begin
if(Reset | StateIdle)
CrcHash[8:0] <= #Tp 9'h0;
else
if(StateData[0] & ByteCntEq6)
CrcHash[8:0] <= #Tp Crc[31:23];
end
// Output byte stream
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
begin
RxData_d[7:0] <= #Tp 8'h0;
DelayData <= #Tp 1'b0;
LatchedNibble[3:0] <= #Tp 4'h0;
LatchedByte[7:0] <= #Tp 8'h0;
RxData[7:0] <= #Tp 8'h0;
end
else
begin
LatchedNibble[3:0] <= #Tp MRxD[3:0]; // Latched nibble
LatchedByte[7:0] <= #Tp {MRxD[3:0], LatchedNibble[3:0]}; // Latched byte
DelayData <= #Tp StateData[0];
if(GenerateRxValid)
RxData_d[7:0] <= #Tp LatchedByte[7:0] & {8{|StateData}}; // Data goes through only in data state
else
if(~DelayData)
RxData_d[7:0] <= #Tp 8'h0; // Delaying data to be valid for two cycles. Zero when not active.
RxData[7:0] <= #Tp RxData_d[7:0]; // Output data byte
end
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
Broadcast <= #Tp 1'b0;
else
begin
if(StateData[0] & ~(&LatchedByte[7:0]) & ByteCntSmall7)
Broadcast <= #Tp 1'b0;
else
if(StateData[0] & (&LatchedByte[7:0]) & ByteCntEq1)
Broadcast <= #Tp 1'b1;
end
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
Multicast <= #Tp 1'b0;
else
begin
if(Reset)
Multicast <= #Tp 1'b0;
else
if(StateData[0] & ByteCntEq1)
Multicast <= #Tp LatchedByte[0];
end
end
assign GenerateRxValid = StateData[0] & (~ByteCntEq0 | DlyCrcCnt >= 4'h3);
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
begin
RxValid_d <= #Tp 1'b0;
RxValid <= #Tp 1'b0;
end
else
begin
RxValid_d <= #Tp GenerateRxValid;
RxValid <= #Tp RxValid_d;
end
end
assign GenerateRxStartFrm = StateData[0] & (ByteCntEq1 & ~DlyCrcEn | DlyCrcCnt == 4'h3 & DlyCrcEn);
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
begin
RxStartFrm_d <= #Tp 1'b0;
RxStartFrm <= #Tp 1'b0;
end
else
begin
RxStartFrm_d <= #Tp GenerateRxStartFrm;
RxStartFrm <= #Tp RxStartFrm_d;
end
end
assign GenerateRxEndFrm = StateData[0] & (~MRxDV & ByteCntGreat2 | ByteCntMaxFrame);
assign DribbleRxEndFrm = StateData[1] & ~MRxDV & ByteCntGreat2;
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
begin
RxEndFrm_d <= #Tp 1'b0;
RxEndFrm <= #Tp 1'b0;
end
else
begin
RxEndFrm_d <= #Tp GenerateRxEndFrm;
RxEndFrm <= #Tp RxEndFrm_d | DribbleRxEndFrm;
end
end
endmodule
