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
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
-- std_logic_1164
-- Copyright (C) 2019 Tristan Gingold
--
-- This file is part of GHDL.
--
-- This program 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.
--
-- This program 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 this program; if not, write to the Free Software
-- Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
-- MA 02110-1301, USA.
package Synth.Ieee.Std_Logic_1164 is
-- From openieee.
-- Unresolved logic state.
type Std_Ulogic is
(
'U', -- Uninitialized, this is also the default value.
'X', -- Unknown / conflict value (forcing level).
'0', -- 0 (forcing level).
'1', -- 1 (forcing level).
'Z', -- High impedance.
'W', -- Unknown / conflict (weak level).
'L', -- 0 (weak level).
'H', -- 1 (weak level).
'-' -- Don't care.
);
subtype X01 is Std_Ulogic range 'X' .. '1';
-- Vector of logic state.
type Std_Logic_Vector is array (Natural range <>) of Std_Ulogic;
type Table_1d is array (Std_Ulogic) of Std_Ulogic;
type Table_2d is array (Std_Ulogic, Std_Ulogic) of Std_Ulogic;
type Table_1d_X01 is array (Std_Ulogic) of X01;
To_X01 : constant Table_1d_X01 := "XX01XX01X";
And_Table : constant Table_2d :=
-- UX01ZWLH-
("UU0UUU0UU", -- U
"UX0XXX0XX", -- X
"000000000", -- 0
"UX01XX01X", -- 1
"UX0XXX0XX", -- Z
"UX0XXX0XX", -- W
"000000000", -- L
"UX01XX01X", -- H
"UX0XXX0XX" -- -
);
Or_Table : constant Table_2d :=
-- UX01ZWLH-
("UUU1UUU1U", -- U
"UXX1XXX1X", -- X
"UX01XX01X", -- 0
"111111111", -- 1
"UXX1XXX1X", -- Z
"UXX1XXX1X", -- W
"UX01XX01X", -- L
"111111111", -- H
"UXX1XXX1X" -- -
);
Xor_Table : constant Table_2d :=
-- UX01ZWLH-
("UUUUUUUUU", -- U
"UXXXXXXXX", -- X
"UX01XX01X", -- 0
"UX10XX10X", -- 1
"UXXXXXXXX", -- Z
"UXXXXXXXX", -- W
"UX01XX01X", -- L
"UX10XX10X", -- H
"UXXXXXXXX" -- -
);
Not_Table : constant Table_1d :=
-- UX01ZWLH-
"UX10XX10X";
end Synth.Ieee.Std_Logic_1164;
|
