sha1_fa_nocout.vhd

本算法基于leon2协处理器接口标准

------------------------------------------------------------------------
--
-- Single-bit adder
--
------------------------------------------------------------------------

LIBRARY ieee;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;
USE ieee.std_logic_unsigned.all;

ENTITY sha1_fa_nocout IS
    PORT (
          a    : in std_logic;
          b    : in std_logic;
          cin  : in std_logic;
          sum  : out std_logic
          );
END sha1_fa_nocout;


-- description of adder using concurrent signal assignments
ARCHITECTURE rtl OF sha1_fa_nocout IS
BEGIN
    sum <= (a xor b) xor cin;
END rtl;