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(wb_rst_i),                   .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),   
  .DeferIndication(DeferIndication),  .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;
wire          AddressMiss;



// 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(wb_rst_i),
  .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), 
  .AddressMiss(AddressMiss),            .PassAll(r_PassAll),                  .ControlFrmAddressOK(ControlFrmAddressOK)
);


// MII Carrier Sense Synchronization
always @ (posedge mtx_clk_pad_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    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 wb_rst_i)
begin
  if(wb_rst_i)
    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 wb_rst_i)
begin
  if(wb_rst_i)
    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 wb_rst_i)
begin
  if(wb_rst_i)
    RxEnSync <= #Tp 1'b0;
  else
  if(~RxCarrierSense | RxCarrierSense & Transmitting)
    RxEnSync <= #Tp r_RxEn;
end 



// Synchronizing WillSendControlFrame to WB_CLK;
always @ (posedge wb_clk_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    WillSendControlFrame_sync1 <= 1'b0;
  else
    WillSendControlFrame_sync1 <=#Tp WillSendControlFrame;
end

always @ (posedge wb_clk_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    WillSendControlFrame_sync2 <= 1'b0;
  else
    WillSendControlFrame_sync2 <=#Tp WillSendControlFrame_sync1;
end

always @ (posedge wb_clk_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    WillSendControlFrame_sync3 <= 1'b0;
  else
    WillSendControlFrame_sync3 <=#Tp WillSendControlFrame_sync2;
end

always @ (posedge wb_clk_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    RstTxPauseRq <= 1'b0;
  else
    RstTxPauseRq <=#Tp WillSendControlFrame_sync2 & ~WillSendControlFrame_sync3;
end




// TX Pause request Synchronization
always @ (posedge mtx_clk_pad_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    begin
      TxPauseRq_sync1 <= #Tp 1'b0;
      TxPauseRq_sync2 <= #Tp 1'b0;
      TxPauseRq_sync3 <= #Tp 1'b0;
    end
  else
    begin
      TxPauseRq_sync1 <= #Tp (r_TxPauseRq & r_TxFlow);
      TxPauseRq_sync2 <= #Tp TxPauseRq_sync1;
      TxPauseRq_sync3 <= #Tp TxPauseRq_sync2;
    end
end


always @ (posedge mtx_clk_pad_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    TPauseRq <= #Tp 1'b0;
  else
    TPauseRq <= #Tp TxPauseRq_sync2 & (~TxPauseRq_sync3);
end


wire LatchedMRxErr;
reg RxAbort_latch;
reg RxAbort_sync1;
reg RxAbort_sync2;
reg RxAbort_wb;
reg RxAbortRst_sync1;
reg RxAbortRst;

// Synchronizing RxAbort to the WISHBONE clock
always @ (posedge mrx_clk_pad_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    RxAbort_latch <= #Tp 1'b0;
  else if(RxAbort | (ShortFrame & ~r_RecSmall) | LatchedMRxErr & ~InvalidSymbol | (ReceivedPauseFrm & (~r_PassAll)))
    RxAbort_latch <= #Tp 1'b1;
  else if(RxAbortRst)
    RxAbort_latch <= #Tp 1'b0;
end

always @ (posedge wb_clk_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    begin
      RxAbort_sync1 <= #Tp 1'b0;
      RxAbort_wb    <= #Tp 1'b0;
      RxAbort_wb    <= #Tp 1'b0;
    end
  else
    begin
      RxAbort_sync1 <= #Tp RxAbort_latch;
      RxAbort_wb    <= #Tp RxAbort_sync1;
    end
end

always @ (posedge mrx_clk_pad_i or posedge wb_rst_i)
begin
  if(wb_rst_i)
    begin
      RxAbortRst_sync1 <= #Tp 1'b0;
      RxAbortRst       <= #Tp 1'b0;
    end
  else
    begin
      RxAbortRst_sync1 <= #Tp RxAbort_wb;
      RxAbortRst       <= #Tp RxAbortRst_sync1;
    end
end



// Connecting Wishbone module
eth_wishbone wishbone
(
  .WB_CLK_I(wb_clk_i),                .WB_DAT_I(wb_dat_i), 
  .WB_DAT_O(BD_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), 

  // 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), 
  
`ifdef ETH_WISHBONE_B3
  .m_wb_cti_o(m_wb_cti_o),            .m_wb_bte_o(m_wb_bte_o), 
`endif
  

    //TX
  .MTxClk(mtx_clk_pad_i),             .TxStartFrm(TxStartFrm),                  .TxEndFrm(TxEndFrm), 
  .TxUsedData(TxUsedData),            .TxData(TxData), 
  .TxRetry(TxRetry),                  .TxAbort(TxAbort),                        .TxUnderRun(TxUnderRun), 
  .TxDone(TxDone), 
  .PerPacketCrcEn(PerPacketCrcEn),    .PerPacketPad(PerPacketPad), 

  // Register
  .r_TxEn(r_TxEn),                    .r_RxEn(r_RxEn),                          .r_TxBDNum(r_TxBDNum), 
  .TX_BD_NUM_Wr(TX_BD_NUM_Wr),        .r_RxFlow(r_RxFlow),                      .r_PassAll(r_PassAll), 

  //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), 

  .RxAbort(RxAbort_wb),               .RxStatusWriteLatched_sync2(RxStatusWriteLatched_sync2), 

  .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),  .AddressMiss(AddressMiss),
  .ReceivedPauseFrm(ReceivedPauseFrm)
  
`ifdef ETH_BIST
  ,
  .scanb_rst      (scanb_rst),
  .scanb_clk      (scanb_clk),
  .scanb_si       (scanb_si),
  .scanb_so       (scanb_so),
  .scanb_en       (scanb_en)
`endif
);



// Connecting MacStatus module
eth_macstatus macstatus1 
(
  .MRxClk(mrx_clk_pad_i),             .Reset(wb_rst_i),
  .ReceiveEnd(ReceiveEnd),            .ReceivedPacketGood(ReceivedPacketGood),     .ReceivedLengthOK(ReceivedLengthOK), 
  .RxCrcError(RxCrcError),            .MRxErr(MRxErr_Lb),                          .MRxDV(MRxDV_Lb), 
  .RxStateSFD(RxStateSFD),            .RxStateData(RxStateData),                   .RxStatePreamble(RxStatePreamble), 
  .RxStateIdle(RxStateIdle),          .Transmitting(Transmitting),                 .RxByteCnt(RxByteCnt), 
  .RxByteCntEq0(RxByteCntEq0),        .RxByteCntGreat2(RxByteCntGreat2),           .RxByteCntMaxFrame(RxByteCntMaxFrame), 
  .InvalidSymbol(InvalidSymbol),
  .MRxD(MRxD_Lb),                     .LatchedCrcError(LatchedCrcError),           .Collision(mcoll_pad_i),
  .CollValid(r_CollValid),            .RxLateCollision(RxLateCollision),           .r_RecSmall(r_RecSmall),
  .r_MinFL(r_MinFL),                  .r_MaxFL(r_MaxFL),                           .ShortFrame(ShortFrame),
  .DribbleNibble(DribbleNibble),      .ReceivedPacketTooBig(ReceivedPacketTooBig), .r_HugEn(r_HugEn),
  .LoadRxStatus(LoadRxStatus),        .RetryCnt(RetryCnt),                         .StartTxDone(StartTxDone),
  .StartTxAbort(StartTxAbort),        .RetryCntLatched(RetryCntLatched),           .MTxClk(mtx_clk_pad_i),
  .MaxCollisionOccured(MaxCollisionOccured), .RetryLimit(RetryLimit),              .LateCollision(LateCollision),
  .LateCollLatched(LateCollLatched),  .DeferIndication(DeferIndication),           .DeferLatched(DeferLatched),
  .TxStartFrm(TxStartFrmOut),         .StatePreamble(StatePreamble),               .StateData(StateData),
  .CarrierSense(CarrierSense_Tx2),    .CarrierSenseLost(CarrierSenseLost),         .TxUsedData(TxUsedDataIn),
  .LatchedMRxErr(LatchedMRxErr),      .Loopback(r_LoopBck),                        .r_FullD(r_FullD)
);


endmodule