Subversion Repositories floating_point_adder_subtractor

library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_arith.all;

use ieee.std_logic_unsigned.all;

-- shift input_b 

entity shift is

port (

                input : in std_logic_vector (32 downto 0);

                diff_exp : in std_logic_vector (7 downto 0);

                clk,finish_swap : in std_logic;

                output_b : out std_logic_vector (32 downto 0);

                finish_shift : out std_logic :='0'

          );

end shift;

architecture shift of shift is

begin

process(input,clk,diff_exp,finish_swap)

variable diff_exp_var : std_logic_vector(7 downto 0);

variable mantissa : std_logic_vector (23 downto 0);

begin

  if (finish_swap='0') then

        output_b <= "000000000000000000000000000000000";

        finish_shift <= '0';

  else

        diff_exp_var := diff_exp ;

        mantissa := input(23 downto 0);

          if (diff_exp > "00000000") then

             for i in 1 to 10 loop

                if (diff_exp_var > "00000000") then

                mantissa(22 downto 0):=mantissa(23 downto 1);

                mantissa(23):='0';

                diff_exp_var:=diff_exp_var - 1;

                end if;

             end loop;

        end if;

  finish_shift <= '1';

  output_b <= input(32 downto 24) & mantissa(23 downto 0);

  end if;

end process;

end shift;