mixcolum.v

面积最小的AES高级加密算法实现

//////////////////////////////////////////////////////////////////////
////                                                              ////
////  Mixcolumns module implementation                            ////
////                                                              ////
////  This file is part of the SystemC AES                        ////
////                                                              ////
////  Description:                                                ////
////  Mixcolum module                                             ////
////                                                              ////
////  Generated automatically using SystemC to Verilog translator ////
////                                                              ////
////  To Do:                                                      ////
////   - done                                                     ////
////                                                              ////
////  Author(s):                                                  ////
////      - Javier Castillo, [e-mail]               ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2000 Authors 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                     ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//
// CVS Revision History
//
// $Log: mixcolum.v,v $
// Revision 1.1  2005/02/14 10:41:01  jcastillo
// 192 bit version uploaded
//
// Revision 1.3  2004/08/30 16:23:57  jcastillo
// Indentation corrected
//
// Revision 1.2  2004/07/22 08:51:22  jcastillo
// Added timescale directive
//
// Revision 1.1.1.1  2004/07/05 09:46:23  jcastillo
// First import
//

`include "timescale.v"

module mixcolum(clk,reset,decrypt_i,start_i,data_i,ready_o,data_o);
input clk;
input reset;
input decrypt_i;
input start_i;
input [127:0] data_i;
output ready_o;
output [127:0] data_o;

reg ready_o;
reg [127:0] data_o;

reg [127:0] data_reg;
reg [127:0] next_data_reg;
reg [127:0] data_o_reg;
reg [127:0] next_data_o;
reg next_ready_o;
reg [1:0] state;
reg [1:0] next_state;

wire [31:0] outx;
wire [31:0] outy;

reg [31:0] mix_word;
reg [31:0] outmux;

word_mixcolum w1 (.in(mix_word), .outx(outx), .outy(outy));

//assign_data_o:
always @(data_o_reg)
begin

  data_o = (data_o_reg);

end


//mux:
always @(outx or outy or decrypt_i)
begin

  outmux = (decrypt_i?outy:outx);

end


//registers:
always @(posedge clk or negedge reset)
begin

  if(!reset)
  begin

    data_reg = (0);
    state = (0);
    ready_o = (0);
    data_o_reg = (0);
  end
  else			  
  begin

    data_reg = (next_data_reg);
    state = (next_state);
    ready_o = (next_ready_o);
    data_o_reg = (next_data_o);

  end

end


//mixcol:
reg[127:0] data_i_var;
reg[31:0] aux;
reg[127:0] data_reg_var;

always @(decrypt_i or start_i or state or data_reg or outmux or data_o_reg or data_i)
begin

  data_i_var=data_i;
  data_reg_var=data_reg;
  next_data_reg = (data_reg);
  next_state = (state);
	
  mix_word = (0);
	
  next_ready_o = (0);
  next_data_o = (data_o_reg);
		
  case(state)

    0:
      begin
        if(start_i)
        begin
          aux=data_i_var[127:96];
          mix_word = (aux);
          data_reg_var[127:96]=outmux;
          next_data_reg = (data_reg_var);
          next_state = (1);
        end
      end
    1:
      begin
        aux=data_i_var[95:64];
        mix_word = (aux);
        data_reg_var[95:64]=outmux;
        next_data_reg = (data_reg_var);
        next_state = (2);
      end
    2:
      begin
        aux=data_i_var[63:32];
        mix_word = (aux);
        data_reg_var[63:32]=outmux;
        next_data_reg = (data_reg_var);
        next_state = (3);
      end
    3:
      begin
        aux=data_i_var[31:0];
        mix_word = (aux);
        data_reg_var[31:0]=outmux;
        next_data_o = (data_reg_var);
        next_ready_o = (1);
        next_state = (0);
      end	
    default:
      begin
      end

endcase

end

endmodule