/////////////////////////////////////////////////////////////////////////                                                             ////////  Tripple DES                                                ////////  Tripple DES Top Level module                               ////////                                                             ////////  Author: Rudolf Usselmann                                   ////////          rudi@asics.ws                                      ////////                                                             /////////////////////////////////////////////////////////////////////////////                                                             //////// Copyright (C) 2002 Rudolf Usselmann                         ////////                    rudi@asics.ws                            ////////                                                             //////// 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 SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     //////// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   //////// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   //////// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      //////// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         //////// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    //////// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   //////// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        //////// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  //////// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  //////// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  //////// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         //////// POSSIBILITY OF SUCH DAMAGE.                                 ////////                                                             /////////////////////////////////////////////////////////////////////////module des3(desOut, desIn, key1, key2, key3, decrypt, clk); output	[63:0]	desOut;input	[63:0]	desIn;input	[55:0]	key1;input	[55:0]	key2;input	[55:0]	key3;input		decrypt;input		clk;wire	[55:0]	key_a;wire	[55:0]	key_b;wire	[55:0]	key_c;wire	[63:0]	stage1_out, stage2_out;reg	[55:0]	key_b_r [16:0];reg	[55:0]	key_c_r [33:0];integer		i;assign key_a = decrypt ? key3 : key1;assign key_b = key2;assign key_c = decrypt ? key1 : key3;always @(posedge clk)	key_b_r[0] <= #1 key_b;always @(posedge clk)	for(i=0;i<16;i=i+1)		key_b_r[i+1] <= #1 key_b_r[i];always @(posedge clk)	key_c_r[0] <= #1 key_c;always @(posedge clk)	for(i=0;i<33;i=i+1)		key_c_r[i+1] <= #1 key_c_r[i];des u0(	.desOut(stage1_out),	.desIn(desIn),		.key(key_a), .decrypt(decrypt), .clk(clk) );des u1(	.desOut(stage2_out),	.desIn(stage1_out),	.key(key_b_r[16]), .decrypt(!decrypt), .clk(clk) );des u2(	.desOut(desOut),	.desIn(stage2_out),	.key(key_c_r[33]), .decrypt(decrypt),	.clk(clk) );endmodule