inverter.vhd

rc5的decryption

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;

ENTITY rc5_enc_inv IS
PORT
(
 clr:IN STD_LOGIC;
 clk:IN STD_LOGIC;
 din:IN STD_LOGIC_VECTOR(63 DOWNTO 0);
 dout:OUT STD_LOGIC_VECTOR(63 DOWNTO 0);
 di_vld:IN STD_LOGIC;
 do_rdy:OUT STD_LOGIC
);
END rc5_enc_inv;

ARCHITECTURE rtl OF rc5_enc_inv IS
     SIGNAL i_cnt:STD_LOGIC_VECTOR(3 DOWNTO 0);
     SIGNAL ab_xor:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL a_rot:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL a:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL a_post:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL a_reg:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL ba_xor:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL b_rot:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL b:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL b_post:STD_LOGIC_VECTOR(31 DOWNTO 0);
     SIGNAL b_reg:STD_LOGIC_VECTOR(31 DOWNTO 0);

TYPE rom IS ARRAY (0 TO 25) OF STD_LOGIC_VECTOR(31 DOWNTO 0);
CONSTANT skey : rom:=rom'(X"9BBBD8C8", X"1A37F7FB", X"46F8E8C5",
     X"460C6085", X"70F83B8A", X"284B8303", X"513E1454", X"F621ED22",
      X"3125065D", X"11A83A5D", X"D427686B", X"713AD82D", X"4B792F99",
      X"2799A4DD", X"A7901C49", X"DEDE871A", X"36C03196", X"A7EFC249",
      X"61A78BB8", X"3B0A1D2B", X"4DBFCA76", X"AE162167", X"30D76B0A",
      X"43192304", X"F6CC1431", X"65046380");

TYPE StateType IS (ST_IDLE,ST_ROUND,ST_POST_ROUND,ST_READY);
SIGNAL state:StateType;

BEGIN

-- B = ((B - S[2i +1]) >>> A) xor A;;
 ab_xor <= b_reg - skey(CONV_INTEGER(i_cnt & '1')); ----b-S[2i+1]
 WITH a_reg(4 DOWNTO 0) SELECT
  b_rot<=ab_xor(0) & ab_xor(31 DOWNTO 1) WHEN "00001",
         ab_xor(1 DOWNTO 0) & ab_xor(31 DOWNTO 2) WHEN "00010",
         ab_xor(2 DOWNTO 0) & ab_xor(31 DOWNTO 3) WHEN "00011",
         ab_xor(3 DOWNTO 0) & ab_xor(31 DOWNTO 4) WHEN "00100",
         ab_xor(4 DOWNTO 0) & ab_xor(31 DOWNTO 5) WHEN "00101",
         ab_xor(5 DOWNTO 0) & ab_xor(31 DOWNTO 6) WHEN "00110",
         ab_xor(6 DOWNTO 0) & ab_xor(31 DOWNTO 7) WHEN "00111",
	 ab_xor(7 DOWNTO 0) & ab_xor(31 DOWNTO 8) WHEN "01000",
         ab_xor(8 DOWNTO 0) & ab_xor(31 DOWNTO 9) WHEN "01001",
	 ab_xor(9 DOWNTO 0) & ab_xor(31 DOWNTO 10) WHEN "01010",
         ab_xor(10 DOWNTO 0) & ab_xor(31 DOWNTO 11) WHEN "01011",
	 ab_xor(11 DOWNTO 0) & ab_xor(31 DOWNTO 12) WHEN "01100",
	 ab_xor(12 DOWNTO 0) & ab_xor(31 DOWNTO 13) WHEN "01101",
	 ab_xor(13 DOWNTO 0) & ab_xor(31 DOWNTO 14) WHEN "01110",
	 ab_xor(14 DOWNTO 0) & ab_xor(31 DOWNTO 15) WHEN "01111",
	 ab_xor(15 DOWNTO 0) & ab_xor(31 DOWNTO 16) WHEN "10000",
	 ab_xor(16 DOWNTO 0) & ab_xor(31 DOWNTO 17) WHEN "10001",
 	 ab_xor(17 DOWNTO 0) & ab_xor(31 DOWNTO 18) WHEN "10010",
         ab_xor(18 DOWNTO 0) & ab_xor(31 DOWNTO 19) WHEN "10011",
         ab_xor(19 DOWNTO 0) & ab_xor(31 DOWNTO 20) WHEN "10100",
         ab_xor(20 DOWNTO 0) & ab_xor(31 DOWNTO 21) WHEN "10101",
         ab_xor(21 DOWNTO 0) & ab_xor(31 DOWNTO 22) WHEN "10110",
         ab_xor(22 DOWNTO 0) & ab_xor(31 DOWNTO 23) WHEN "10111",
	 ab_xor(23 DOWNTO 0) & ab_xor(31 DOWNTO 24) WHEN "11000",
         ab_xor(24 DOWNTO 0) & ab_xor(31 DOWNTO 25) WHEN "11001",
         ab_xor(25 DOWNTO 0) & ab_xor(31 DOWNTO 26) WHEN "11010",
         ab_xor(26 DOWNTO 0) & ab_xor(31 DOWNTO 27) WHEN "11011",
	 ab_xor(27 DOWNTO 0) & ab_xor(31 DOWNTO 28) WHEN "11100",
         ab_xor(28 DOWNTO 0) & ab_xor(31 DOWNTO 29) WHEN "11101",
         ab_xor(29 DOWNTO 0) & ab_xor(31 DOWNTO 30) WHEN "11110",
         ab_xor(30 DOWNTO 0) & ab_xor(31) WHEN "11111",
         ab_xor WHEN OTHERS;
   b<=b_rot XOR a_reg;

--A = ((A - S[2i]) >>> B) xor B;
  ba_xor <= a_reg - skey(CONV_INTEGER(i_cnt & '0'));---a-S[2i]
  WITH b(4 DOWNTO 0) SELECT
  a_rot<=ba_xor(0) & ba_xor(31 DOWNTO 1) WHEN "00001",
         ba_xor(1 DOWNTO 0) & ba_xor(31 DOWNTO 2) WHEN "00010",
         ba_xor(2 DOWNTO 0) & ba_xor(31 DOWNTO 3) WHEN "00011",
         ba_xor(3 DOWNTO 0) & ba_xor(31 DOWNTO 4) WHEN "00100",
         ba_xor(4 DOWNTO 0) & ba_xor(31 DOWNTO 5) WHEN "00101",
         ba_xor(5 DOWNTO 0) & ba_xor(31 DOWNTO 6) WHEN "00110",
         ba_xor(6 DOWNTO 0) & ba_xor(31 DOWNTO 7) WHEN "00111",
	 ba_xor(7 DOWNTO 0) & ba_xor(31 DOWNTO 8) WHEN "01000",
         ba_xor(8 DOWNTO 0) & ba_xor(31 DOWNTO 9) WHEN "01001",
	 ba_xor(9 DOWNTO 0) & ba_xor(31 DOWNTO 10) WHEN "01010",
         ba_xor(10 DOWNTO 0) & ba_xor(31 DOWNTO 11) WHEN "01011",
	 ba_xor(11 DOWNTO 0) & ba_xor(31 DOWNTO 12) WHEN "01100",
	 ba_xor(12 DOWNTO 0) & ba_xor(31 DOWNTO 13) WHEN "01101",
	 ba_xor(13 DOWNTO 0) & ba_xor(31 DOWNTO 14) WHEN "01110",
	 ba_xor(14 DOWNTO 0) & ba_xor(31 DOWNTO 15) WHEN "01111",
	 ba_xor(15 DOWNTO 0) & ba_xor(31 DOWNTO 16) WHEN "10000",
	 ba_xor(16 DOWNTO 0) & ba_xor(31 DOWNTO 17) WHEN "10001",
 	 ba_xor(17 DOWNTO 0) & ba_xor(31 DOWNTO 18) WHEN "10010",
         ba_xor(18 DOWNTO 0) & ba_xor(31 DOWNTO 19) WHEN "10011",
         ba_xor(19 DOWNTO 0) & ba_xor(31 DOWNTO 20) WHEN "10100",
         ba_xor(20 DOWNTO 0) & ba_xor(31 DOWNTO 21) WHEN "10101",
         ba_xor(21 DOWNTO 0) & ba_xor(31 DOWNTO 22) WHEN "10110",
         ba_xor(22 DOWNTO 0) & ba_xor(31 DOWNTO 23) WHEN "10111",
	 ba_xor(23 DOWNTO 0) & ba_xor(31 DOWNTO 24) WHEN "11000",
         ba_xor(24 DOWNTO 0) & ba_xor(31 DOWNTO 25) WHEN "11001",
         ba_xor(25 DOWNTO 0) & ba_xor(31 DOWNTO 26) WHEN "11010",
         ba_xor(26 DOWNTO 0) & ba_xor(31 DOWNTO 27) WHEN "11011",
	 ba_xor(27 DOWNTO 0) & ba_xor(31 DOWNTO 28) WHEN "11100",
         ba_xor(28 DOWNTO 0) & ba_xor(31 DOWNTO 29) WHEN "11101",
         ba_xor(29 DOWNTO 0) & ba_xor(31 DOWNTO 30) WHEN "11110",
         ba_xor(30 DOWNTO 0) & ba_xor(31) WHEN "11111",
         ba_xor WHEN OTHERS;
    a<=a_rot XOR b; 
    
    a_post <= a_reg - skey(0); 
    b_post<=b_reg - skey(1); -- b = b[0] - S[1]
    
    PROCESS(clr, clk)  BEGIN
        IF(clr='0') THEN
           a_reg<= din(63 DOWNTO 32);
           b_reg<= din(31 DOWNTO 0);
           ELSIF(clk'EVENT AND clk='1') THEN
             IF(state=ST_POST_ROUND) THEN   a_reg<=a_post;b_reg<=b_post;
             ELSIF(state=ST_ROUND) THEN   a_reg<=a;b_reg<=b;    END IF;
        END IF;
    END PROCESS;

   PROCESS(clr, clk)
   BEGIN
      IF(clr='0') THEN
         state<=ST_IDLE;
      ELSIF(clk'EVENT AND clk='1') THEN
         CASE state IS
            WHEN ST_IDLE=>  IF(di_vld='1') THEN state<=ST_ROUND;  END IF;
            WHEN ST_ROUND=> IF(i_cnt="0001") THEN state<=ST_POST_ROUND;  END IF;  
            WHEN ST_POST_ROUND=> state<=ST_READY;
            WHEN ST_READY=>   state<=ST_IDLE;
         END CASE;
      END IF;
   END PROCESS;

-- round counter
    PROCESS(clr, clk)  BEGIN
        IF(clr='0') THEN
           i_cnt<="1100";
        ELSIF(clk'EVENT AND clk='1') THEN
           IF(state=ST_ROUND) THEN
              IF(i_cnt="0001") THEN   i_cnt<="1100";
              ELSE    i_cnt<=i_cnt-'1';    END IF;
           END IF;
        END IF;
    END PROCESS;   

dout<=a_reg & b_reg;

    WITH state SELECT
        do_rdy<='1' WHEN ST_READY,
		'0' WHEN OTHERS;
END rtl;