-----------------------------------------------------------------------				(c) Copyright 2006, CoreTex Systems, LLC					 ----		                   www.coretexsys.com                        --    --                                                            		 ----		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.                                  ----																						 ----------------------------------------------------------------------------------------------------------------------------------------------- Poject structure: --  |- tdes_top.vhd--  |--    |- des_cipher_top.vhd--    |- des_top.vhd--      |- block_top.vhd--        |- add_key.vhd--        |--        |- add_left.vhd--        |--				|- e_expansion_function.vhd--				|--				|- p_box.vhd--				|--				|- s_box.vhd--            |- s1_box.vhd--            |- s2_box.vhd--            |- s3_box.vhd--            |- s4_box.vhd--            |- s5_box.vhd--            |- s6_box.vhd--            |- s7_box.vhd--            |- s8_box.vhd--    |- key_schedule.vhd----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Title       : s4_box-- Company     : CoreTex Systems, LLC-----------------------------------------------------------------------------------------------------library IEEE;use IEEE.STD_LOGIC_1164.ALL;use IEEE.STD_LOGIC_ARITH.ALL;use IEEE.STD_LOGIC_UNSIGNED.ALL;ENTITY s4_box IS	port (	A: IN std_logic_VECTOR(5 downto 0);	SPO: OUT std_logic_VECTOR(3 downto 0));END s4_box;architecture Behavioral of s4_box isbeginSPO 	<= "0111" when A = x"0" else			"1101" when A = x"1" else			"1101" when A = x"2" else			"1000" when A = x"3" else			"1110" when A = x"4" else			"1011" when A = x"5" else			"0011" when A = x"6" else			"0101" when A = x"7" else			"0000" when A = x"8" else			"0110" when A = x"9" else			"0110" when A = x"A" else			"1111" when A = x"B" else			"1001" when A = x"C" else			"0000" when A = x"D" else			"1010" when A = x"E" else			"0011" when A = x"F" else			"0001" when A = x"10" else			"0100" when A = x"11" else			"0010" when A = x"12" else			"0111" when A = x"13" else			"1000" when A = x"14" else			"0010" when A = x"15" else			"0101" when A = x"16" else			"1100" when A = x"17" else			"1011" when A = x"18" else			"0001" when A = x"19" else			"1100" when A = x"1A" else			"1010" when A = x"1B" else			"0100" when A = x"1C" else			"1110" when A = x"1D" else			"1111" when A = x"1E" else			"1001" when A = x"1F" else			"1010" when A = x"20" else			"0011" when A = x"21" else			"0110" when A = x"22" else			"1111" when A = x"23" else			"1001" when A = x"24" else			"0000" when A = x"25" else			"0000" when A = x"26" else			"0110" when A = x"27" else			"1100" when A = x"28" else			"1010" when A = x"29" else			"1011" when A = x"2A" else			"0001" when A = x"2B" else			"0111" when A = x"2C" else			"1101" when A = x"2D" else			"1101" when A = x"2E" else			"1000" when A = x"2F" else			"1111" when A = x"30" else			"1001" when A = x"31" else			"0001" when A = x"32" else			"0100" when A = x"33" else			"0011" when A = x"34" else			"0101" when A = x"35" else			"1110" when A = x"36" else			"1011" when A = x"37" else			"0101" when A = x"38" else			"1100" when A = x"39" else			"0010" when A = x"3A" else			"0111" when A = x"3B" else			"1000" when A = x"3C" else			"0010" when A = x"3D" else			"0100" when A = x"3E" else			"1110" when A = x"3F" else			"1110";END Behavioral;