1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
-- Copyright (C) 2002 Morgan Kaufmann Publishers, Inc
-- This file is part of VESTs (Vhdl tESTs).
-- VESTs is free software; you can redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the
-- Free Software Foundation; either version 2 of the License, or (at
-- your option) any later version.
-- VESTs is distributed in the hope that it will be useful, but WITHOUT
-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-- for more details.
-- You should have received a copy of the GNU General Public License
-- along with VESTs; if not, write to the Free Software Foundation,
-- Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
entity full_adder is
port ( a, b, c_in : bit; s, c_out : out bit );
end entity full_adder;
architecture truth_table of full_adder is
begin
with bit_vector'(a, b, c_in) select
(c_out, s) <= bit_vector'("00") when "000",
bit_vector'("01") when "001",
bit_vector'("01") when "010",
bit_vector'("10") when "011",
bit_vector'("01") when "100",
bit_vector'("10") when "101",
bit_vector'("10") when "110",
bit_vector'("11") when "111";
end architecture truth_table;
|