Subversion Repositories aes_decrypt_fpga

////////////////////////////////////////////////////////////////// ////
////                                                                                                                            ////
//// AES Decryption Core for FPGA                                                                       ////
////                                                                                                                            ////
//// This file is part of the AES Decryption Core for FPGA project      ////
//// http://www.opencores.org/cores/xxx/                                                        ////
////                                                                                                                            ////
//// Description                                                                                                        ////
//// Implementation of  AES Decryption Core for FPGA according to       ////
//// core specification document.                                                                       ////
////                                                                                                                            ////
//// To Do:                                                                                                             ////
//// -                                                                                                                          ////
////                                                                                                                            ////
//// Author(s):                                                                                                         ////
//// - scheng, schengopencores@opencores.org                                            ////
////                                                                                                                            ////
//////////////////////////////////////////////////////////////////////
////                                                                                                                            ////
//// Copyright (C) 2009 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                                           ////
////                                                                                                                            //// ///
///////////////////////////////////////////////////////////////////
////                                                                                                                            ////
//// InvMixColumns() as defined in section 5.3.3 of FIPS-197 spec,      ////
//// or feed input through to output when bypass=1.                                     ////
////                                                                                                                            ////
//// Feed through is used during the first and last round where         ////
//// InvMixColumns() is not needed.                                                                     ////
////                                                                                                                            ////
////////////////////////////////////////////////////////////////////////
module InvMixColumns(
        input   [0:127] din,
        output  [0:127] dout,
        input   bypass);
        
        wire    [0:31]  newcol [0:3];

        // 4 instances of InvMixCol_slice, each computes one column of InvMixColumns()
        //  as defined in section 5.3.3 of FIPS-197 spec.
        genvar j;
        generate
                for (j=0; j<4; j++)     
                        InvMixCol_slice i_mixcol_u
                                (
                                .S0c(din[(32*j)+:8]),
                                .S1c(din[(32*j + 8)+:8]),
                                .S2c(din[(32*j + 16)+:8]),
                                .S3c(din[(32*j + 24)+:8]),
                                .bypass(bypass),
                                .new_S(newcol[j])
                                );
        endgenerate
                                
        assign dout = {newcol[0], newcol[1],newcol[2], newcol[3]};              
endmodule