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                                           ////
////                                                                                                                            //// ///
///////////////////////////////////////////////////////////////////
////                                                                                                                            ////
//// Decryption engine                                                                                          ////
////                                                                                                                            ////
//// Wrapper for 256-bit AES decryption                                                         ////
////                                                                                                                            ////
////////////////////////////////////////////////////////////////////////
module aes_decrypt256(
        input   [0:255] kt,
        input   kt_vld,         // Active high input informing key expander that a valid new key is present at kt.
        output  kt_rdy,         // Active high output indicates decryptor ready to accept new key.
        
        input   [0:127] ct,     // Ciphertext input
        input   ct_vld,         // Active high input indicates a valid ciphertext present on ct.
        output  ct_rdy,         // Active high output indicates decryptor ready to accept new ct.
        
        output  [0:127] pt,     // Plaintext output
        output  pt_vld,         // Active high output indicates valid plaintext available on pt.
        
        input   clk,
        input   rst
        );
        
        // Decryptor side
        wire    [0:127] rkey_decrypt;
        wire    rkey_vld_decrypt;
        wire    next_rkey_decrypt;
        
        // Key Expander side
        wire    [0:127] rkey_keyexp;
        wire    rkey_vld_keyexp;
        
        (* KEEP_HIRARACHY = "yes" *) KschBuffer KschBuffer_u(.rkey_in(rkey_keyexp),
                                                        .rkey_vld_in(rkey_vld_keyexp),
                                                        .rkey_out(rkey_decrypt),
                                                        .rkey_vld_out(rkey_vld_decrypt),
                                                        .next_rkey(next_rkey_decrypt),
                                                        .klen_sel(2'b10),       // 2'b10 selects 256-bit key
                                                        .clk(clk),
                                                        .rst(rst)
                                                        );
                                                        
        (* KEEP_HIRARACHY = "yes" *) KeyExpand256 KeyExpand256_u(
                                                        .kt(kt),
                                                        .kt_vld(kt_vld),
                                                        .kt_rdy(kt_rdy),
                                                        .rkey(rkey_keyexp),
                                                        .rkey_vld(rkey_vld_keyexp),
                                                        .rkey_last(),
                                                        .clk(clk),
                                                        .rst(rst)
                                                        );
                                                        
        (* KEEP_HIRARACHY = "yes" *) decrypt decrypt_u( .ct(ct),
                                        .ct_vld(ct_vld),
                                        .ct_rdy(ct_rdy),
                                        .rkey(rkey_decrypt),
                                        .rkey_vld(rkey_vld_decrypt),
                                        .next_rkey(next_rkey_decrypt),
                                        .pt(pt),
                                        .pt_vld(pt_vld),
                                        .klen_sel(2'b10),       // 2'b10 selects 256-bit key
                                        .clk(clk),
                                        .rst(rst)
                                        );
endmodule