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//////////////////////////////////////////////////////////////////////
////                                                              ////
//// spiTxRxData.v                                                ////
////                                                              ////
//// This file is part of the spiMaster opencores effort.
//// <http://www.opencores.org/cores//>                           ////
////                                                              ////
//// Module Description:                                          ////
////  Mux access to SPI RX and TX data 
//// 
////  
//// 
////                                                              ////
//// To Do:                                                       ////
////   
////                                                              ////
//// Author(s):                                                   ////
//// - Steve Fielding, sfielding@base2designs.com                 ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2008 Steve Fielding and OPENCORES.ORG          ////
////                                                              ////
//// 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>                   ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//`include "timescale.v"
 
module spiTxRxData (
  clk,
  rst,
 
  tx1DataIn,
  tx2DataIn,
  tx3DataIn,
  tx4DataIn,
  tx1DataWEn,
  tx2DataWEn,
  tx3DataWEn,
  tx4DataWEn,
 
  txDataOut,
  txDataFull,
  txDataFullClr,
 
  rx1DataRdyClr,
  rx2DataRdyClr,
  rx3DataRdyClr,
  rx4DataRdyClr,
 
  rxDataIn,
  rxDataOut,
  rxDataRdy,
  rxDataRdySet
);
 
input clk;
input rst;
 
input [7:0] tx1DataIn;
input [7:0] tx2DataIn;
input [7:0] tx3DataIn;
input [7:0] tx4DataIn;
input tx1DataWEn;
input tx2DataWEn;
input tx3DataWEn;
input tx4DataWEn;
 
output [7:0] txDataOut;
reg [7:0] txDataOut;
output txDataFull;
reg txDataFull;
input txDataFullClr;
 
input rx1DataRdyClr;
input rx2DataRdyClr;
input rx3DataRdyClr;
input rx4DataRdyClr;
 
input [7:0] rxDataIn;
output [7:0] rxDataOut;
reg [7:0] rxDataOut;
output rxDataRdy;
reg rxDataRdy;
input rxDataRdySet;
 
 
// --- Transmit control
always @(posedge clk) begin
  if (rst == 1'b1) begin
    txDataOut <= 8'h00;
    txDataFull <= 1'b0;
  end
  else begin
    if (tx1DataWEn == 1'b1) begin
      txDataOut <= tx1DataIn;
      txDataFull <= 1'b1;
    end
    else if (tx2DataWEn == 1'b1) begin
      txDataOut <= tx2DataIn;
      txDataFull <= 1'b1;
    end
    else if (tx3DataWEn == 1'b1) begin
      txDataOut <= tx3DataIn;
      txDataFull <= 1'b1;
    end
    else if (tx4DataWEn == 1'b1) begin
      txDataOut <= tx4DataIn;
      txDataFull <= 1'b1;
    end
    if (txDataFullClr == 1'b1)
      txDataFull <= 1'b0;
  end
end
 
// --- Receive control
always @(posedge clk) begin
  if (rst == 1'b1) begin
    rxDataOut <= 8'h00;
    rxDataRdy <= 1'b0;
  end
  else begin
    if (rx1DataRdyClr == 1'b1 || rx2DataRdyClr == 1'b1 || rx3DataRdyClr == 1'b1 || rx4DataRdyClr == 1'b1) begin
      rxDataRdy <= 1'b0;
    end
    if (rxDataRdySet == 1'b1) begin
      rxDataRdy <= 1'b1;
      rxDataOut <= rxDataIn;
    end
  end
end
 
endmodule