-- --------------------------------------------------------------------------
--
-- Title      : Draft Standard VHDL 1076.1.1 Packages for Multiple Energy 
--            : Domain Support.
--
-- Library    : This package shall be compiled into a library symbolically
--            : named IEEE.
--
-- Developers : IEEE 1076.1.1 Working Group,
--
-- Purpose    : This package contains declarations that are common across
--            : energy domains.
--
-- Note       :
--
-- --------------------------------------------------------------------------
--   Modification History :
--
--   Version   Date           Description
--     1.0     6 July 2001    Original version.
--     1.1     4 March 2002   FDL 2001 & BMAS 2001 revisions
--     1.2     31 Aug 2002    DAC 2002 revisions (removed physical and material
--                            constants - moved to constants_pkg_v1.vhd)
--     1.3     30 Sep 2002    FDL 2002 revisions
-- --------------------------------------------------------------------------
library IEEE;
   use IEEE.FUNDAMENTAL_CONSTANTS.all;

package ENERGY_SYSTEMS is

   -- type declarations

   -- subtype declarations
   subtype ENERGY      is REAL tolerance "DEFAULT_ENERGY";
   subtype POWER       is REAL tolerance "DEFAULT_POWER";
   subtype PERIODICITY is REAL tolerance "DEFAULT_PERIODICITY";

   -- attribute declarations
   attribute UNIT of ENERGY      : subtype is "Joule";
   attribute UNIT of POWER       : subtype is "Watt";
   attribute UNIT of PERIODICITY : subtype is "";
   attribute SYMBOL of ENERGY      : subtype is "J";
   attribute SYMBOL of POWER       : subtype is "W";
   attribute SYMBOL of PERIODICITY : subtype is "";

   -- nature declarations

   -- vector subtype declarations
   subtype ENERGY_VECTOR      is REAL_VECTOR tolerance "DEFAULT_ENERGY";
   subtype POWER_VECTOR       is REAL_VECTOR tolerance "DEFAULT_POWER";
   subtype PERIODICITY_VECTOR is REAL_VECTOR tolerance "DEFAULT_PERIODICITY";

   -- attributes of vector subtypes
   attribute UNIT of ENERGY_VECTOR      : subtype is "Joule";
   attribute UNIT of POWER_VECTOR       : subtype is "Watt";
   attribute UNIT of PERIODICITY_VECTOR : subtype is "";
   attribute SYMBOL of ENERGY_VECTOR      : subtype is "J";
   attribute SYMBOL of POWER_VECTOR       : subtype is "W";
   attribute SYMBOL of PERIODICITY_VECTOR : subtype is "";

   -- subnature declarations

   -- object declarations

   -- operation declarations (e.g., subprograms)

   -- alias declarations
end package ENERGY_SYSTEMS;