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-- Interpreter AMS simulation
-- Copyright (C) 2014 Tristan Gingold
--
-- GHDL 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, or (at your option) any later
-- version.
--
-- GHDL 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 GHDL; see the file COPYING. If not, write to the Free
-- Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-- 02111-1307, USA.
with GNAT.Table;
package Simulation.AMS is
-- AMS expressions
--
-- At many places during elaboration, the LRM defines characteristic
-- expressions that aren't present in source code:
-- * contribution expression (12.3.1.4)
-- * characteristic expression for an across quantity declaration
-- (12.3.1.4)
-- * characteristic expression for simple simultaneous statement (the
-- expression is in the source in that case) (15.1)
--
-- They are represented using a list of Ams_Expression elements. The value
-- is the sum of each element, using the + or - sign.
type Ams_Sign is (Op_Plus, Op_Minus);
-- Sign for the operand
type Ams_Operand is (Op_Quantity, Op_Vhdl_Expr);
-- The operand is one of:
-- Op_Quantity: a quantity
-- Op_Vhdl_Expr: an expression from the design. This expression may contain
-- quantities
type Ams_Term (<>) is private;
type Ams_Term_Acc is access Ams_Term;
-- A term of a characteristic expression
type Characteristic_Expr_Kind is
(Explicit,
Contribution,
Structural);
type Tolerance_Index_Type is new Natural;
Default_Tolerance_Index : constant Tolerance_Index_Type := 0;
-- Tolerance
type Characteristic_Expressions_Index is new Natural;
type Quantity_Kind is
(Quantity_Reference,
-- The potential of a terminal. This is an across quantity between the
-- terminal and the reference terminal of the nature.
Quantity_Across,
Quantity_Through,
Quantity_Free
-- Explicitly declared quantities
);
function Create_Scalar_Quantity (Kind : Quantity_Kind;
Decl : Iir;
Instance : Block_Instance_Acc)
return Quantity_Index_Type;
-- Create a new scalar quantity
function Create_Scalar_Terminal (Decl : Iir;
Instance : Block_Instance_Acc)
return Terminal_Index_Type;
-- Create a new scalar terminal
function Get_Terminal_Reference (Terminal : Terminal_Index_Type)
return Quantity_Index_Type;
-- Get the reference quantity of a terminal
procedure Add_Characteristic_Expression
(Kind : Characteristic_Expr_Kind; Expr : Ams_Term_Acc);
-- Add a new characteristic expression
function Build (Op : Ams_Sign;
Val : Quantity_Index_Type;
Right : Ams_Term_Acc := null)
return Ams_Term_Acc;
function Build (Op : Ams_Sign;
Instance : Block_Instance_Acc;
Expr : Iir;
Right : Ams_Term_Acc := null)
return Ams_Term_Acc;
-- Build a term of a characteristic expression
procedure Append_Characteristic_Expression
(Terminal : Terminal_Index_Type; Expr : Ams_Term_Acc);
-- Append an expression to the contribution of a terminal
procedure Create_Tables;
private
type Quantity_Index_Array is array (Positive range <>)
of Quantity_Index_Type;
type Quantity_Dependency_Type (Nbr : Natural);
type Quantity_Dependency_Acc is access Quantity_Dependency_Type;
type Quantity_Dependency_Type (Nbr : Natural) is record
Quantities : Quantity_Index_Array (1 .. Nbr);
end record;
type Ams_Term (Op : Ams_Operand) is record
Sign : Ams_Sign;
Next : Ams_Term_Acc;
case Op is
when Op_Quantity =>
Quantity : Quantity_Index_Type;
when Op_Vhdl_Expr =>
Vhdl_Expr : Iir;
Vhdl_Instance : Block_Instance_Acc;
end case;
end record;
type Characteristic_Expr is record
Kind : Characteristic_Expr_Kind;
Expr : Ams_Term_Acc;
Tolerance : Tolerance_Index_Type;
Dependencies : Quantity_Dependency_Acc;
end record;
package Characteristic_Expressions is new Gnat.Table
(Table_Index_Type => Characteristic_Expressions_Index,
Table_Component_Type => Characteristic_Expr,
Table_Low_Bound => 1,
Table_Initial => 128,
Table_Increment => 100);
type Scalar_Quantity (Kind : Quantity_Kind := Quantity_Reference) is record
Value : Ghdl_F64;
-- The value of the quantity
Decl : Iir;
Instance : Block_Instance_Acc;
-- Declaration for the quantity
case Kind is
when Quantity_Reference =>
Contribution : Characteristic_Expressions_Index;
when others =>
null;
end case;
end record;
package Scalar_Quantities is new Gnat.Table
(Table_Index_Type => Quantity_Index_Type,
Table_Component_Type => Scalar_Quantity,
Table_Low_Bound => 1,
Table_Initial => 128,
Table_Increment => 100);
end Simulation.AMS;
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