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-- ------------------------------------------------------------------------
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-- Copyright (C) 2005 Arif Endro Nugroho
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-- All rights reserved.
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--
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-- Redistribution and use in source and binary forms, with or without
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-- modification, are permitted provided that the following conditions
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-- are met:
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--
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-- 1. Redistributions of source code must retain the above copyright
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-- notice, this list of conditions and the following disclaimer.
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-- 2. Redistributions in binary form must reproduce the above copyright
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-- notice, this list of conditions and the following disclaimer in the
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-- documentation and/or other materials provided with the distribution.
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--
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-- THIS SOFTWARE IS PROVIDED BY ARIF ENDRO NUGROHO "AS IS" AND ANY EXPRESS
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-- OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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-- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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-- DISCLAIMED. IN NO EVENT SHALL ARIF ENDRO NUGROHO BE LIABLE FOR ANY
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-- DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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-- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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-- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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-- STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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-- ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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-- POSSIBILITY OF SUCH DAMAGE.
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--
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-- End Of License.
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-- ------------------------------------------------------------------------
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library IEEE;
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use IEEE.std_logic_1164.all;
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entity twos_c_8bit is
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port (
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twos_c_i : in bit_vector (07 downto 00);
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twos_c_o : out bit_vector (07 downto 00)
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);
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end twos_c_8bit;
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architecture data_flow of twos_c_8bit is
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begin
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twos_c_o(00) <= (twos_c_i(00));
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twos_c_o(01) <= (not(twos_c_i(01)) xor (not(twos_c_i(00))));
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twos_c_o(02) <= (not(twos_c_i(02)) xor (not(twos_c_i(00)) and not(twos_c_i(01))));
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twos_c_o(03) <= (not(twos_c_i(03)) xor ((not(twos_c_i(00)) and not(twos_c_i(01))) and not(twos_c_i(02))));
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twos_c_o(04) <= (not(twos_c_i(04)) xor ((not(twos_c_i(00)) and not(twos_c_i(01))) and (not(twos_c_i(02)) and not(twos_c_i(03)))));
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twos_c_o(05) <= (not(twos_c_i(05)) xor (((not(twos_c_i(00)) and not(twos_c_i(01))) and (not(twos_c_i(02)) and not(twos_c_i(03)))) and not(twos_c_i(04))));
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twos_c_o(06) <= (not(twos_c_i(06)) xor (((not(twos_c_i(00)) and not(twos_c_i(01))) and (not(twos_c_i(02)) and not(twos_c_i(03)))) and (not(twos_c_i(04)) and not(twos_c_i(05)))));
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twos_c_o(07) <= (not(twos_c_i(07)) xor (((not(twos_c_i(00)) and not(twos_c_i(01))) and (not(twos_c_i(02)) and not(twos_c_i(03)))) and ((not(twos_c_i(04)) and not(twos_c_i(05))) and not(twos_c_i(06)))));
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end data_flow;
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