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[/] [present/] [trunk/] [32BitIO/] [rtl/] [vhdl/] [outputRegister.vhd] - Blame information for rev 4

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1 4 gajos
-----------------------------------------------------------------------
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----                                                               ----
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---- Present - a lightweight block cipher project                  ----
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----                                                               ----
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---- This file is part of the Present - a lightweight block        ----
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---- cipher project                                                ----
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---- http://www.http://opencores.org/project,present               ----
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----                                                               ----
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---- Description:                                                  ----
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----     Not "pure" registers. Main function of this component is  ----
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---- to convert 64 bit input to 32 bit output. For more see below. ----
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---- To Do:                                                        ----
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----                                                               ----
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---- Author(s):                                                    ----
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---- - Krzysztof Gajewski, gajos@opencores.org                     ----
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----                       k.gajewski@gmail.com                    ----
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----                                                               ----
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-----------------------------------------------------------------------
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----                                                               ----
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---- Copyright (C) 2013 Authors and OPENCORES.ORG                  ----
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----                                                               ----
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---- This source file may be used and distributed without          ----
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---- restriction provided that this copyright statement is not     ----
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---- removed from the file and that any derivative work contains   ----
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---- the original copyright notice and the associated disclaimer.  ----
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----                                                               ----
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---- This source file is free software; you can redistribute it    ----
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---- and-or modify it under the terms of the GNU Lesser General    ----
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---- Public License as published by the Free Software Foundation;  ----
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---- either version 2.1 of the License, or (at your option) any    ----
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---- later version.                                                ----
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----                                                               ----
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---- This source is distributed in the hope that it will be        ----
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---- useful, but WITHOUT ANY WARRANTY; without even the implied    ----
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---- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR       ----
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---- PURPOSE. See the GNU Lesser General Public License for more   ----
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---- details.                                                      ----
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----                                                               ----
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---- You should have received a copy of the GNU Lesser General     ----
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---- Public License along with this source; if not, download it    ----
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---- from http://www.opencores.org/lgpl.shtml                      ----
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----                                                               ----
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-----------------------------------------------------------------------
44 2 gajos
library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use work.kody.ALL;
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-- Uncomment the following library declaration if using
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-- arithmetic functions with Signed or Unsigned values
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--use IEEE.NUMERIC_STD.ALL;
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entity outputRegister is
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        generic (
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                w_2 : integer := 2;
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                w_32: integer := 32;
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                w_64: integer := 64
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        );
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   port(
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                rst, clk, rd : in std_logic;
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                ctrl : in std_logic_vector(w_2-1 downto 0);
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                input : in std_logic_vector(w_64-1 downto 0);
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                output : out std_logic_vector(w_32-1 downto 0);
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                ready : out std_logic
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   );
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end outputRegister;
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architecture Behavioral of outputRegister is
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        signal reg : std_logic_vector(w_64-1 downto 0);
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        begin
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                process( rst, clk, ctrl, input)
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                        begin
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                                if (rst = '1') then
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                                        output <= (others=>'Z');
74 4 gajos
                                elsif(clk'event and clk = '1') then
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                                    -- loading internal signal
76 2 gajos
                                        if(ctrl = out_ld_reg) then
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                                                reg <= input;
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                                                output <= (others=>'Z');
79 4 gajos
                                        ---- leas significant 32 bits to output
80 2 gajos
                                        elsif (ctrl = out_reg_L) then
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                                                output <= reg(w_32-1 downto 0);
82 4 gajos
                                        ---- most significant 32 bits to output
83 2 gajos
                                        elsif (ctrl = out_reg_H) then
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                                                output <= reg(w_64-1 downto w_32);
85 4 gajos
                                        ---- this should not happen
86 2 gajos
                                        else
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                                                output <= (others=>'Z');
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                                        end if;
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                                end if;
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                        end process;
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                        ready <= rd;
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        end Behavioral;
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