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-- -----------------------------------------------------------------
--
-- Copyright 2019 IEEE P1076 WG Authors
--
-- See the LICENSE file distributed with this work for copyright and
-- licensing information and the AUTHORS file.
--
-- This file to you under the Apache License, Version 2.0 (the "License").
-- You may obtain a copy of the License at
--
-- http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
-- implied. See the License for the specific language governing
-- permissions and limitations under the License.
--
-- Title : Standard multivalue logic package
-- : (STD_LOGIC_1164 package declaration)
-- :
-- Library : This package shall be compiled into a library
-- : symbolically named IEEE.
-- :
-- Developers: IEEE model standards group (PAR 1164),
-- : Accellera VHDL-TC, and IEEE P1076 Working Group
-- :
-- Purpose : This packages defines a standard for designers
-- : to use in describing the interconnection data types
-- : used in vhdl modeling.
-- :
-- Limitation: The logic system defined in this package may
-- : be insufficient for modeling switched transistors,
-- : since such a requirement is out of the scope of this
-- : effort. Furthermore, mathematics, primitives,
-- : timing standards, etc. are considered orthogonal
-- : issues as it relates to this package and are therefore
-- : beyond the scope of this effort.
-- :
-- Note : This package may be modified to include additional data
-- : required by tools, but it must in no way change the
-- : external interfaces or simulation behavior of the
-- : description. It is permissible to add comments and/or
-- : attributes to the package declarations, but not to change
-- : or delete any original lines of the package declaration.
-- : The package body may be changed only in accordance with
-- : the terms of Clause 16 of this standard.
-- :
-- --------------------------------------------------------------------
-- $Revision: 1228 $
-- $Date: 2008-04-30 10:04:53 +0930 (Wed, 30 Apr 2008) $
-- --------------------------------------------------------------------
package std_logic_1164 is
-------------------------------------------------------------------
-- logic state system (unresolved)
-------------------------------------------------------------------
type STD_ULOGIC is ( 'U', -- Uninitialized
'X', -- Forcing Unknown
'0', -- Forcing 0
'1', -- Forcing 1
'Z', -- High Impedance
'W', -- Weak Unknown
'L', -- Weak 0
'H', -- Weak 1
'-' -- Don't care
);
-------------------------------------------------------------------
-- unconstrained array of std_ulogic for use with the resolution function
-- and for use in declaring signal arrays of unresolved elements
-------------------------------------------------------------------
type STD_ULOGIC_VECTOR is array (NATURAL range <>) of STD_ULOGIC;
-------------------------------------------------------------------
-- resolution function
-------------------------------------------------------------------
function resolved (s : STD_ULOGIC_VECTOR) return STD_ULOGIC;
-------------------------------------------------------------------
-- logic state system (resolved)
-------------------------------------------------------------------
subtype STD_LOGIC is resolved STD_ULOGIC;
-------------------------------------------------------------------
-- unconstrained array of resolved std_ulogic for use in declaring
-- signal arrays of resolved elements
-------------------------------------------------------------------
type STD_LOGIC_VECTOR is array (NATURAL range <>) of STD_LOGIC;
-------------------------------------------------------------------
-- common subtypes
-------------------------------------------------------------------
subtype X01 is resolved STD_ULOGIC range 'X' to '1'; -- ('X','0','1')
subtype X01Z is resolved STD_ULOGIC range 'X' to 'Z'; -- ('X','0','1','Z')
subtype UX01 is resolved STD_ULOGIC range 'U' to '1'; -- ('U','X','0','1')
subtype UX01Z is resolved STD_ULOGIC range 'U' to 'Z'; -- ('U','X','0','1','Z')
-------------------------------------------------------------------
-- overloaded logical operators
-------------------------------------------------------------------
function "and" (l : STD_ULOGIC; r : STD_ULOGIC) return UX01;
function "nand" (l : STD_ULOGIC; r : STD_ULOGIC) return UX01;
function "or" (l : STD_ULOGIC; r : STD_ULOGIC) return UX01;
function "nor" (l : STD_ULOGIC; r : STD_ULOGIC) return UX01;
function "xor" (l : STD_ULOGIC; r : STD_ULOGIC) return UX01;
function "xnor" (l : STD_ULOGIC; r : STD_ULOGIC) return UX01; --!V87
function "not" (l : STD_ULOGIC) return UX01;
-------------------------------------------------------------------
-- vectorized overloaded logical operators
-------------------------------------------------------------------
function "and" (l, r : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function "and" (l, r : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function "nand" (l, r : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function "nand" (l, r : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function "or" (l, r : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function "or" (l, r : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function "nor" (l, r : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function "nor" (l, r : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function "xor" (l, r : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function "xor" (l, r : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function "xnor" (l, r : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR; --!V87
function "xnor" (l, r : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR; --!V87
function "not" (l : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function "not" (l : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
-------------------------------------------------------------------
-- conversion functions
-------------------------------------------------------------------
function To_bit (s : STD_ULOGIC; xmap : BIT := '0') return BIT;
function To_bitvector (s : STD_LOGIC_VECTOR; xmap : BIT := '0') return BIT_VECTOR;
function To_bitvector (s : STD_ULOGIC_VECTOR; xmap : BIT := '0') return BIT_VECTOR;
function To_StdULogic (b : BIT) return STD_ULOGIC;
function To_StdLogicVector (b : BIT_VECTOR) return STD_LOGIC_VECTOR;
function To_StdLogicVector (s : STD_ULOGIC_VECTOR) return STD_LOGIC_VECTOR;
function To_StdULogicVector (b : BIT_VECTOR) return STD_ULOGIC_VECTOR;
function To_StdULogicVector (s : STD_LOGIC_VECTOR) return STD_ULOGIC_VECTOR;
-------------------------------------------------------------------
-- strength strippers and type convertors
-------------------------------------------------------------------
function To_X01 (s : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function To_X01 (s : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function To_X01 (s : STD_ULOGIC) return X01;
function To_X01 (b : BIT_VECTOR) return STD_LOGIC_VECTOR;
function To_X01 (b : BIT_VECTOR) return STD_ULOGIC_VECTOR;
function To_X01 (b : BIT) return X01;
function To_X01Z (s : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function To_X01Z (s : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function To_X01Z (s : STD_ULOGIC) return X01Z;
function To_X01Z (b : BIT_VECTOR) return STD_LOGIC_VECTOR;
function To_X01Z (b : BIT_VECTOR) return STD_ULOGIC_VECTOR;
function To_X01Z (b : BIT) return X01Z;
function To_UX01 (s : STD_LOGIC_VECTOR) return STD_LOGIC_VECTOR;
function To_UX01 (s : STD_ULOGIC_VECTOR) return STD_ULOGIC_VECTOR;
function To_UX01 (s : STD_ULOGIC) return UX01;
function To_UX01 (b : BIT_VECTOR) return STD_LOGIC_VECTOR;
function To_UX01 (b : BIT_VECTOR) return STD_ULOGIC_VECTOR;
function To_UX01 (b : BIT) return UX01;
-------------------------------------------------------------------
-- edge detection
-------------------------------------------------------------------
function rising_edge (signal s : STD_ULOGIC) return BOOLEAN;
function falling_edge (signal s : STD_ULOGIC) return BOOLEAN;
-------------------------------------------------------------------
-- object contains an unknown
-------------------------------------------------------------------
function Is_X (s : STD_ULOGIC_VECTOR) return BOOLEAN;
function Is_X (s : STD_LOGIC_VECTOR) return BOOLEAN;
function Is_X (s : STD_ULOGIC) return BOOLEAN;
end std_logic_1164;
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