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

////                                                              ////

////  eth_top.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: not supported by cvs2svn $

// Revision 1.22  2002/02/26 16:59:54  mohor

// Small fixes for external/internal DMA missmatches.

//

// Revision 1.21  2002/02/26 16:21:00  mohor

// Interrupts changed in the top file

//

// Revision 1.20  2002/02/18 10:40:17  mohor

// Small fixes.

//

// Revision 1.19  2002/02/16 14:03:44  mohor

// Registered trimmed. Unused registers removed.

//

// Revision 1.18  2002/02/16 13:06:33  mohor

// EXTERNAL_DMA used instead of WISHBONE_DMA.

//

// Revision 1.17  2002/02/16 07:15:27  mohor

// Testbench fixed, code simplified, unused signals removed.

//

// Revision 1.16  2002/02/15 13:49:39  mohor

// RxAbort is connected differently.

//

// Revision 1.15  2002/02/15 11:38:26  mohor

// Changes that were lost when updating from 1.11 to 1.14 fixed.

//

// Revision 1.14  2002/02/14 20:19:11  billditt

// Modified for Address Checking,

// addition of eth_addrcheck.v

//

// Revision 1.13  2002/02/12 17:03:03  mohor

// HASH0 and HASH1 registers added. Registers address width was

// changed to 8 bits.

//

// Revision 1.12  2002/02/11 09:18:22  mohor

// Tx status is written back to the BD.

//

// Revision 1.11  2002/02/08 16:21:54  mohor

// Rx status is written back to the BD.

//

// Revision 1.10  2002/02/06 14:10:21  mohor

// non-DMA host interface added. Select the right configutation in eth_defines.

//

// Revision 1.9  2002/01/23 10:28:16  mohor

// Link in the header changed.

//

// Revision 1.8  2001/12/05 15:00:16  mohor

// RX_BD_NUM changed to TX_BD_NUM (holds number of TX descriptors

// instead of the number of RX descriptors).

//

// Revision 1.7  2001/12/05 10:45:59  mohor

// ETH_RX_BD_ADR register deleted. ETH_RX_BD_NUM is used instead.

//

// Revision 1.6  2001/10/19 11:24:29  mohor

// Number of addresses (wb_adr_i) minimized.

//

// Revision 1.5  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 1.4  2001/10/18 12:07:11  mohor

// Status signals changed, Adress decoding changed, interrupt controller

// added.

//

// Revision 1.3  2001/09/24 15:02:56  mohor

// Defines changed (All precede with ETH_). Small changes because some

// tools generate warnings when two operands are together. Synchronization

// between two clocks domains in eth_wishbonedma.v is changed (due to ASIC

// demands).

//

// Revision 1.2  2001/08/15 14:03:59  mohor

// Signal names changed on the top level for easier pad insertion (ASIC).

//

// 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 1.2  2001/08/02 09:25:31  mohor

// Unconnected signals are now connected.

//

// Revision 1.1  2001/07/30 21:23:42  mohor

// Directory structure changed. Files checked and joind together.

//

//

//

// 

`include "eth_defines.v"

`include "timescale.v"

module eth_top

(

  // WISHBONE common

  wb_clk_i, wb_rst_i, wb_dat_i, wb_dat_o,

  // WISHBONE slave

  wb_adr_i, wb_sel_i, wb_we_i, wb_cyc_i, wb_stb_i, wb_ack_o, wb_err_o,

`ifdef EXTERNAL_DMA

  wb_ack_i, wb_req_o, wb_nd_o, wb_rd_o,

`else

  // WISHBONE master

  m_wb_adr_o, m_wb_sel_o, m_wb_we_o,

  m_wb_dat_o, m_wb_dat_i, m_wb_cyc_o,

  m_wb_stb_o, m_wb_ack_i, m_wb_err_i,

`endif

  //TX

  mtx_clk_pad_i, mtxd_pad_o, mtxen_pad_o, mtxerr_pad_o,

  //RX

  mrx_clk_pad_i, mrxd_pad_i, mrxdv_pad_i, mrxerr_pad_i, mcoll_pad_i, mcrs_pad_i,

  // MIIM

  mdc_pad_o, md_pad_i, md_pad_o, md_padoe_o,

  int_o

);

parameter Tp = 1;

// WISHBONE common

input           wb_clk_i;     // WISHBONE clock

input           wb_rst_i;     // WISHBONE reset

input   [31:0]  wb_dat_i;     // WISHBONE data input

output  [31:0]  wb_dat_o;     // WISHBONE data output

output          wb_err_o;     // WISHBONE error output

// WISHBONE slave

input   [11:2]  wb_adr_i;     // WISHBONE address input

input    [3:0]  wb_sel_i;     // WISHBONE byte select input

input           wb_we_i;      // WISHBONE write enable input

input           wb_cyc_i;     // WISHBONE cycle input

input           wb_stb_i;     // WISHBONE strobe input

output          wb_ack_o;     // WISHBONE acknowledge output

`ifdef EXTERNAL_DMA

// DMA

input    [1:0]  wb_ack_i;     // DMA acknowledge input

output   [1:0]  wb_req_o;     // DMA request output

output   [1:0]  wb_nd_o;      // DMA force new descriptor output

output          wb_rd_o;      // DMA restart descriptor output

`else

// WISHBONE master

output  [31:0]  m_wb_adr_o;

output   [3:0]  m_wb_sel_o;

output          m_wb_we_o;

input   [31:0]  m_wb_dat_i;

output  [31:0]  m_wb_dat_o;

output          m_wb_cyc_o;

output          m_wb_stb_o;

input           m_wb_ack_i;

input           m_wb_err_i;

`endif

// Tx

input           mtx_clk_pad_i; // Transmit clock (from PHY)

output   [3:0]  mtxd_pad_o;    // Transmit nibble (to PHY)

output          mtxen_pad_o;   // Transmit enable (to PHY)

output          mtxerr_pad_o;  // Transmit error (to PHY)

// Rx

input           mrx_clk_pad_i; // Receive clock (from PHY)

input    [3:0]  mrxd_pad_i;    // Receive nibble (from PHY)

input           mrxdv_pad_i;   // Receive data valid (from PHY)

input           mrxerr_pad_i;  // Receive data error (from PHY)

// Common Tx and Rx

input           mcoll_pad_i;   // Collision (from PHY)

input           mcrs_pad_i;    // Carrier sense (from PHY)

// MII Management interface

input           md_pad_i;      // MII data input (from I/O cell)

output          mdc_pad_o;     // MII Management data clock (to PHY)

output          md_pad_o;      // MII data output (to I/O cell)

output          md_padoe_o;    // MII data output enable (to I/O cell)

output          int_o;         // Interrupt output

wire     [7:0]  r_ClkDiv;

wire            r_MiiNoPre;

wire    [15:0]  r_CtrlData;

wire     [4:0]  r_FIAD;

wire     [4:0]  r_RGAD;

wire            r_WCtrlData;

wire            r_RStat;

wire            r_ScanStat;

wire            NValid_stat;

wire            Busy_stat;

wire            LinkFail;

wire            r_MiiMRst;

wire    [15:0]  Prsd;             // Read Status Data (data read from the PHY)

wire            WCtrlDataStart;

wire            RStatStart;

wire            UpdateMIIRX_DATAReg;

wire            TxStartFrm;

wire            TxEndFrm;

wire            TxUsedData;

wire     [7:0]  TxData;

wire            TxRetry;

wire            TxAbort;

wire            TxUnderRun;

wire            TxDone;

wire     [5:0]  CollValid;

// Connecting Miim module

eth_miim miim1

(

  .Clk(wb_clk_i),                         .Reset(r_MiiMRst),                  .Divider(r_ClkDiv),

  .NoPre(r_MiiNoPre),                     .CtrlData(r_CtrlData),              .Rgad(r_RGAD),

  .Fiad(r_FIAD),                          .WCtrlData(r_WCtrlData),            .RStat(r_RStat),

  .ScanStat(r_ScanStat),                  .Mdi(md_pad_i),                     .Mdo(md_pad_o),

  .MdoEn(md_padoe_o),                     .Mdc(mdc_pad_o),                    .Busy(Busy_stat),

  .Prsd(Prsd),                            .LinkFail(LinkFail),                .Nvalid(NValid_stat),

  .WCtrlDataStart(WCtrlDataStart),        .RStatStart(RStatStart),            .UpdateMIIRX_DATAReg(UpdateMIIRX_DATAReg)

);

wire        RegCs;          // Connected to registers

wire [31:0] RegDataOut;     // Multiplexed to wb_dat_o

wire        r_RecSmall;     // Receive small frames

wire        r_Rst;          // Reset

wire        r_LoopBck;      // Loopback

wire        r_TxEn;         // Tx Enable

wire        r_RxEn;         // Rx Enable

wire        MRxDV_Lb;       // Muxed MII receive data valid

wire        MRxErr_Lb;      // Muxed MII Receive Error

wire  [3:0] MRxD_Lb;        // Muxed MII Receive Data

wire        Transmitting;   // Indication that TxEthMAC is transmitting

wire        r_HugEn;        // Huge packet enable

wire        r_DlyCrcEn;     // Delayed CRC enabled

wire [15:0] r_MaxFL;        // Maximum frame length

wire [15:0] r_MinFL;        // Minimum frame length

wire        ShortFrame;

wire        DribbleNibble;  // Extra nibble received

wire        ReceivedPacketTooBig; // Received packet is too big

wire [47:0] r_MAC;          // MAC address

wire        LoadRxStatus;   // Rx status was loaded

wire [31:0] r_HASH0;        // HASH table, lower 4 bytes

wire [31:0] r_HASH1;        // HASH table, upper 4 bytes

wire  [7:0] r_TxBDNum;      // Receive buffer descriptor number

wire  [6:0] r_IPGT;         // 

wire  [6:0] r_IPGR1;        // 

wire  [6:0] r_IPGR2;        // 

wire  [5:0] r_CollValid;    // 

wire        r_TPauseRq;     // Transmit PAUSE request pulse

wire  [3:0] r_MaxRet;       //

wire        r_NoBckof;      // 

wire        r_ExDfrEn;      // 

wire        TX_BD_NUM_Wr;   // Write enable that writes RX_BD_NUM to the registers.

wire        TPauseRq;       // Sinhronized Tx PAUSE request

wire [15:0] TxPauseTV;      // Tx PAUSE timer value

wire        r_TxFlow;       // Tx flow control enable

wire        r_IFG;          // Minimum interframe gap for incoming packets

wire        TxB_IRQ;        // Interrupt Tx Buffer

wire        TxE_IRQ;        // Interrupt Tx Error

wire        RxB_IRQ;        // Interrupt Rx Buffer

wire        RxE_IRQ;        // Interrupt Rx Error

wire        Busy_IRQ;       // Interrupt Busy (lack of buffers)

wire        TxC_IRQ;        // Interrupt Tx Control Frame

wire        RxC_IRQ;        // Interrupt Rx Control Frame

wire        DWord;

wire        BDAck;

wire [31:0] DMA_WB_DAT_O;   // wb_dat_o that comes from the WishboneDMA module

wire        BDCs;           // Buffer descriptor CS

assign DWord = &wb_sel_i;

assign RegCs = wb_stb_i & wb_cyc_i & DWord & ~wb_adr_i[11] & ~wb_adr_i[10];

assign BDCs  = wb_stb_i & wb_cyc_i & DWord & ~wb_adr_i[11] &  wb_adr_i[10];

assign wb_ack_o = RegCs | BDAck;

assign wb_err_o = wb_stb_i & wb_cyc_i & ~DWord;

// Selecting the WISHBONE output data

assign wb_dat_o[31:0] = (RegCs & ~wb_we_i)? RegDataOut : DMA_WB_DAT_O;

// Connecting Ethernet registers

eth_registers ethreg1

(

  .DataIn(wb_dat_i),                      .Address(wb_adr_i[9:2]),                    .Rw(wb_we_i),

  .Cs(RegCs),                             .Clk(wb_clk_i),                             .Reset(wb_rst_i),

  .DataOut(RegDataOut),                   .r_RecSmall(r_RecSmall),

  .r_Pad(r_Pad),                          .r_HugEn(r_HugEn),                          .r_CrcEn(r_CrcEn),

  .r_DlyCrcEn(r_DlyCrcEn),                .r_Rst(r_Rst),                              .r_FullD(r_FullD),

  .r_ExDfrEn(r_ExDfrEn),                  .r_NoBckof(r_NoBckof),                      .r_LoopBck(r_LoopBck),

  .r_IFG(r_IFG),                          .r_Pro(r_Pro),                              .r_Iam(),

  .r_Bro(r_Bro),                          .r_NoPre(r_NoPre),                          .r_TxEn(r_TxEn),

  .r_RxEn(r_RxEn),                        .Busy_IRQ(Busy_IRQ),                        .RxE_IRQ(RxE_IRQ),

  .RxB_IRQ(RxB_IRQ),                      .TxE_IRQ(TxE_IRQ),                          .TxB_IRQ(TxB_IRQ),

  .TxC_IRQ(TxC_IRQ),                      .RxC_IRQ(RxC_IRQ),                          .r_IPGT(r_IPGT),

  .r_IPGR1(r_IPGR1),                      .r_IPGR2(r_IPGR2),                          .r_MinFL(r_MinFL),

  .r_MaxFL(r_MaxFL),                      .r_MaxRet(r_MaxRet),                        .r_CollValid(r_CollValid),

  .r_TxFlow(r_TxFlow),                    .r_RxFlow(r_RxFlow),                        .r_PassAll(r_PassAll),

  .r_MiiMRst(r_MiiMRst),                  .r_MiiNoPre(r_MiiNoPre),                    .r_ClkDiv(r_ClkDiv),

  .r_WCtrlData(r_WCtrlData),              .r_RStat(r_RStat),                          .r_ScanStat(r_ScanStat),

  .r_RGAD(r_RGAD),                        .r_FIAD(r_FIAD),                            .r_CtrlData(r_CtrlData),

  .NValid_stat(NValid_stat),              .Busy_stat(Busy_stat),

  .LinkFail(LinkFail),                    .r_MAC(r_MAC),                              .WCtrlDataStart(WCtrlDataStart),

  .RStatStart(RStatStart),                .UpdateMIIRX_DATAReg(UpdateMIIRX_DATAReg),  .Prsd(Prsd),

  .r_TxBDNum(r_TxBDNum),                  .TX_BD_NUM_Wr(TX_BD_NUM_Wr),                .int_o(int_o),

  .r_HASH0(r_HASH0),                      .r_HASH1(r_HASH1)

);

wire  [7:0] RxData;

wire        RxValid;

wire        RxStartFrm;

wire        RxEndFrm;

wire        RxAbort;

wire        WillTransmit;            // Will transmit (to RxEthMAC)

wire        ResetCollision;          // Reset Collision (for synchronizing collision)

wire  [7:0] TxDataOut;               // Transmit Packet Data (to TxEthMAC)

wire        WillSendControlFrame;

wire        TxCtrlEndFrm;

wire        ReceivedPauseFrm;

wire        ReceiveEnd;

wire        ReceivedPacketGood;

wire        ReceivedLengthOK;

wire        InvalidSymbol;

wire        LatchedCrcError;

wire        RxLateCollision;

wire  [3:0] RetryCntLatched;

wire  [3:0] RetryCnt;

wire        StartTxDone;

wire        StartTxAbort;

wire        MaxCollisionOccured;

wire        RetryLimit;

wire        StatePreamble;

wire  [1:0] StateData;

// Connecting MACControl

eth_maccontrol maccontrol1

(

  .MTxClk(mtx_clk_pad_i),                       .TPauseRq(TPauseRq),

  .TxPauseTV(TxPauseTV),                        .TxDataIn(TxData),

  .TxStartFrmIn(TxStartFrm),                    .TxEndFrmIn(TxEndFrm),

  .TxUsedDataIn(TxUsedDataIn),                  .TxDoneIn(TxDoneIn),

  .TxAbortIn(TxAbortIn),                        .MRxClk(mrx_clk_pad_i),

  .RxData(RxData),                              .RxValid(RxValid),

  .RxStartFrm(RxStartFrm),                      .RxEndFrm(RxEndFrm),

  .ReceiveEnd(ReceiveEnd),                      .ReceivedPacketGood(ReceivedPacketGood),

  .PassAll(r_PassAll),                          .TxFlow(r_TxFlow),

  .RxFlow(r_RxFlow),                            .DlyCrcEn(r_DlyCrcEn),

  .MAC(r_MAC),                                  .PadIn(r_Pad | PerPacketPad),

  .PadOut(PadOut),                              .CrcEnIn(r_CrcEn | PerPacketCrcEn),

  .CrcEnOut(CrcEnOut),                          .TxReset(r_Rst),

  .RxReset(r_Rst),                              .ReceivedLengthOK(ReceivedLengthOK),

  .TxDataOut(TxDataOut),                        .TxStartFrmOut(TxStartFrmOut),

  .TxEndFrmOut(TxEndFrmOut),                    .TxUsedDataOut(TxUsedData),

  .TxDoneOut(TxDone),                           .TxAbortOut(TxAbort),

  .WillSendControlFrame(WillSendControlFrame),  .TxCtrlEndFrm(TxCtrlEndFrm),

  .ReceivedPauseFrm(ReceivedPauseFrm)

);

wire TxCarrierSense;          // Synchronized CarrierSense (to Tx clock)

wire Collision;               // Synchronized Collision

reg CarrierSense_Tx1;

reg CarrierSense_Tx2;

reg Collision_Tx1;

reg Collision_Tx2;

reg RxEnSync;                 // Synchronized Receive Enable

reg CarrierSense_Rx1;

reg RxCarrierSense;           // Synchronized CarrierSense (to Rx clock)

reg WillTransmit_q;

reg WillTransmit_q2;

// Muxed MII receive data valid

assign MRxDV_Lb = r_LoopBck? mtxen_pad_o : mrxdv_pad_i & RxEnSync;

// Muxed MII Receive Error

assign MRxErr_Lb = r_LoopBck? mtxerr_pad_o : mrxerr_pad_i & RxEnSync;

// Muxed MII Receive Data

assign MRxD_Lb[3:0] = r_LoopBck? mtxd_pad_o[3:0] : mrxd_pad_i[3:0];

// Connecting TxEthMAC

eth_txethmac txethmac1

(

  .MTxClk(mtx_clk_pad_i),             .Reset(r_Rst),                      .CarrierSense(TxCarrierSense),

  .Collision(Collision),              .TxData(TxDataOut),                 .TxStartFrm(TxStartFrmOut),

  .TxUnderRun(TxUnderRun),            .TxEndFrm(TxEndFrmOut),             .Pad(PadOut),

  .MinFL(r_MinFL),                    .CrcEn(CrcEnOut),                   .FullD(r_FullD),

  .HugEn(r_HugEn),                    .DlyCrcEn(r_DlyCrcEn),              .IPGT(r_IPGT),

  .IPGR1(r_IPGR1),                    .IPGR2(r_IPGR2),                    .CollValid(r_CollValid),

  .MaxRet(r_MaxRet),                  .NoBckof(r_NoBckof),                .ExDfrEn(r_ExDfrEn),

  .MaxFL(r_MaxFL),                    .MTxEn(mtxen_pad_o),                .MTxD(mtxd_pad_o),

  .MTxErr(mtxerr_pad_o),              .TxUsedData(TxUsedDataIn),          .TxDone(TxDoneIn),

  .TxRetry(TxRetry),                  .TxAbort(TxAbortIn),                .WillTransmit(WillTransmit),

  .ResetCollision(ResetCollision),    .RetryCnt(RetryCnt),                .StartTxDone(StartTxDone),

  .StartTxAbort(StartTxAbort),        .MaxCollisionOccured(MaxCollisionOccured), .LateCollision(LateCollision),

  .StartDefer(StartDefer),            .StatePreamble(StatePreamble),      .StateData(StateData)

);

wire  [15:0]  RxByteCnt;

wire          RxByteCntEq0;

wire          RxByteCntGreat2;

wire          RxByteCntMaxFrame;

wire          RxCrcError;

wire          RxStateIdle;

wire          RxStatePreamble;

wire          RxStateSFD;

wire   [1:0]  RxStateData;

// Connecting RxEthMAC

eth_rxethmac rxethmac1

(

  .MRxClk(mrx_clk_pad_i),               .MRxDV(MRxDV_Lb),                     .MRxD(MRxD_Lb),

  .Transmitting(Transmitting),          .HugEn(r_HugEn),                      .DlyCrcEn(r_DlyCrcEn),

  .MaxFL(r_MaxFL),                      .r_IFG(r_IFG),                        .Reset(r_Rst),

  .RxData(RxData),                      .RxValid(RxValid),                    .RxStartFrm(RxStartFrm),

  .RxEndFrm(RxEndFrm),                  .ByteCnt(RxByteCnt),

  .ByteCntEq0(RxByteCntEq0),            .ByteCntGreat2(RxByteCntGreat2),      .ByteCntMaxFrame(RxByteCntMaxFrame),

  .CrcError(RxCrcError),                .StateIdle(RxStateIdle),              .StatePreamble(RxStatePreamble),

  .StateSFD(RxStateSFD),                .StateData(RxStateData),

  .MAC(r_MAC),                          .r_Pro(r_Pro),                        .r_Bro(r_Bro),

  .r_HASH0(r_HASH0),                    .r_HASH1(r_HASH1),                    .RxAbort(RxAbort)

);

// MII Carrier Sense Synchronization

always @ (posedge mtx_clk_pad_i or posedge r_Rst)

begin

  if(r_Rst)

    begin

      CarrierSense_Tx1 <= #Tp 1'b0;

      CarrierSense_Tx2 <= #Tp 1'b0;

    end

  else

    begin

      CarrierSense_Tx1 <= #Tp mcrs_pad_i;

      CarrierSense_Tx2 <= #Tp CarrierSense_Tx1;

    end

end

assign TxCarrierSense = ~r_FullD & CarrierSense_Tx2;

// MII Collision Synchronization

always @ (posedge mtx_clk_pad_i or posedge r_Rst)

begin

  if(r_Rst)

    begin

      Collision_Tx1 <= #Tp 1'b0;

      Collision_Tx2 <= #Tp 1'b0;

    end

  else

    begin

      Collision_Tx1 <= #Tp mcoll_pad_i;

      if(ResetCollision)

        Collision_Tx2 <= #Tp 1'b0;

      else

      if(Collision_Tx1)

        Collision_Tx2 <= #Tp 1'b1;

    end

end

// Synchronized Collision

assign Collision = ~r_FullD & Collision_Tx2;

// Carrier sense is synchronized to receive clock.

always @ (posedge mrx_clk_pad_i or posedge r_Rst)

begin

  if(r_Rst)

    begin

      CarrierSense_Rx1 <= #Tp 1'h0;

      RxCarrierSense <= #Tp 1'h0;

    end

  else

    begin

      CarrierSense_Rx1 <= #Tp mcrs_pad_i;

      RxCarrierSense <= #Tp CarrierSense_Rx1;

    end

end

// Delayed WillTransmit

always @ (posedge mrx_clk_pad_i)

begin

  WillTransmit_q <= #Tp WillTransmit;

  WillTransmit_q2 <= #Tp WillTransmit_q;

end

assign Transmitting = ~r_FullD & WillTransmit_q2;

// Synchronized Receive Enable

always @ (posedge mrx_clk_pad_i or posedge r_Rst)

begin

  if(r_Rst)

    RxEnSync <= #Tp 1'b0;

  else

  if(~RxCarrierSense | RxCarrierSense & Transmitting)

    RxEnSync <= #Tp r_RxEn;

end

// Connecting WishboneDMA module

`ifdef EXTERNAL_DMA

eth_wishbonedma wishbone

`else

eth_wishbone wishbone

`endif

(

  .WB_CLK_I(wb_clk_i),                .WB_DAT_I(wb_dat_i),

  .WB_DAT_O(DMA_WB_DAT_O),

  // WISHBONE slave

  .WB_ADR_I(wb_adr_i[9:2]),           .WB_WE_I(wb_we_i),

  .BDCs(BDCs),                        .WB_ACK_O(BDAck),

  .Reset(wb_rst_i),

`ifdef EXTERNAL_DMA

  .WB_REQ_O(wb_req_o),                .WB_ND_O(wb_nd_o),                        .WB_RD_O(wb_rd_o),

  .WB_ACK_I(wb_ack_i),                .r_DmaEn(1'b1),

`else

  // WISHBONE master

  .m_wb_adr_o(m_wb_adr_o),            .m_wb_sel_o(m_wb_sel_o),                  .m_wb_we_o(m_wb_we_o),

  .m_wb_dat_i(m_wb_dat_i),            .m_wb_dat_o(m_wb_dat_o),                  .m_wb_cyc_o(m_wb_cyc_o),

  .m_wb_stb_o(m_wb_stb_o),            .m_wb_ack_i(m_wb_ack_i),                  .m_wb_err_i(m_wb_err_i),

`endif

    //TX

  .MTxClk(mtx_clk_pad_i),             .TxStartFrm(TxStartFrm),                  .TxEndFrm(TxEndFrm),

  .TxUsedData(TxUsedData),            .TxData(TxData),

  .TxRetry(TxRetry),                  .TxAbort(TxAbort),                        .TxUnderRun(TxUnderRun),

  .TxDone(TxDone),                    .TPauseRq(TPauseRq),                      .TxPauseTV(TxPauseTV),

  .PerPacketCrcEn(PerPacketCrcEn),    .PerPacketPad(PerPacketPad),              .WillSendControlFrame(WillSendControlFrame),

  .TxCtrlEndFrm(TxCtrlEndFrm),

  // Register

  .r_TxEn(r_TxEn),                    .r_RxEn(r_RxEn),                          .r_TxBDNum(r_TxBDNum),

  .TX_BD_NUM_Wr(TX_BD_NUM_Wr),        .r_RecSmall(r_RecSmall),

  //RX

  .MRxClk(mrx_clk_pad_i),             .RxData(RxData),                          .RxValid(RxValid),

  .RxStartFrm(RxStartFrm),            .RxEndFrm(RxEndFrm),

  .Busy_IRQ(Busy_IRQ),                .RxE_IRQ(RxE_IRQ),                        .RxB_IRQ(RxB_IRQ),

  .TxE_IRQ(TxE_IRQ),                  .TxB_IRQ(TxB_IRQ),                        .TxC_IRQ(TxC_IRQ),

  .RxC_IRQ(RxC_IRQ),

  .RxAbort(RxAbort),

  .InvalidSymbol(InvalidSymbol),      .LatchedCrcError(LatchedCrcError),        .RxLength(RxByteCnt),

  .RxLateCollision(RxLateCollision),  .ShortFrame(ShortFrame),                  .DribbleNibble(DribbleNibble),

  .ReceivedPacketTooBig(ReceivedPacketTooBig), .LoadRxStatus(LoadRxStatus),     .RetryCntLatched(RetryCntLatched),

  .RetryLimit(RetryLimit),            .LateCollLatched(LateCollLatched),        .DeferLatched(DeferLatched),

  .CarrierSenseLost(CarrierSenseLost),.ReceivedPacketGood(ReceivedPacketGood)