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authorTristan Gingold <tgingold@free.fr>2014-01-04 11:25:55 +0100
committerTristan Gingold <tgingold@free.fr>2014-01-04 11:25:55 +0100
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+-- --------------------------------------------------------------------
+--
+-- Copyright © 2008 by IEEE. All rights reserved.
+--
+-- This source file is an essential part of IEEE Std 1076-2008,
+-- IEEE Standard VHDL Language Reference Manual. This source file may not be
+-- copied, sold, or included with software that is sold without written
+-- permission from the IEEE Standards Department. This source file may be
+-- copied for individual use between licensed users. This source file is
+-- provided on an AS IS basis. The IEEE disclaims ANY WARRANTY EXPRESS OR
+-- IMPLIED INCLUDING ANY WARRANTY OF MERCHANTABILITY AND FITNESS FOR USE
+-- FOR A PARTICULAR PURPOSE. The user of the source file shall indemnify
+-- and hold IEEE harmless from any damages or liability arising out of the
+-- use thereof.
+--
+-- Title : Standard VHDL Mathematical Packages
+-- : (MATH_REAL package declaration)
+-- :
+-- Library : This package shall be compiled into a library
+-- : symbolically named IEEE.
+-- :
+-- Developers: IEEE DASC VHDL Mathematical Packages Working Group
+-- :
+-- Purpose : This package defines a standard for designers to use in
+-- : describing VHDL models that make use of common REAL
+-- : constants and common REAL elementary mathematical
+-- : functions.
+-- :
+-- Limitation: The values generated by the functions in this package
+-- : may vary from platform to platform, and the precision
+-- : of results is only guaranteed to be the minimum required
+-- : by IEEE Std 1076-2008.
+-- :
+-- 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: 1220 $
+-- $Date: 2008-04-10 17:16:09 +0930 (Thu, 10 Apr 2008) $
+-- --------------------------------------------------------------------
+
+package MATH_REAL is
+ constant CopyRightNotice : STRING
+ := "Copyright 2008 IEEE. All rights reserved.";
+
+ --
+ -- Constant Definitions
+ --
+ constant MATH_E : REAL := 2.71828_18284_59045_23536;
+ -- Value of e
+ constant MATH_1_OVER_E : REAL := 0.36787_94411_71442_32160;
+ -- Value of 1/e
+ constant MATH_PI : REAL := 3.14159_26535_89793_23846;
+ -- Value of pi
+ constant MATH_2_PI : REAL := 6.28318_53071_79586_47693;
+ -- Value of 2*pi
+ constant MATH_1_OVER_PI : REAL := 0.31830_98861_83790_67154;
+ -- Value of 1/pi
+ constant MATH_PI_OVER_2 : REAL := 1.57079_63267_94896_61923;
+ -- Value of pi/2
+ constant MATH_PI_OVER_3 : REAL := 1.04719_75511_96597_74615;
+ -- Value of pi/3
+ constant MATH_PI_OVER_4 : REAL := 0.78539_81633_97448_30962;
+ -- Value of pi/4
+ constant MATH_3_PI_OVER_2 : REAL := 4.71238_89803_84689_85769;
+ -- Value 3*pi/2
+ constant MATH_LOG_OF_2 : REAL := 0.69314_71805_59945_30942;
+ -- Natural log of 2
+ constant MATH_LOG_OF_10 : REAL := 2.30258_50929_94045_68402;
+ -- Natural log of 10
+ constant MATH_LOG2_OF_E : REAL := 1.44269_50408_88963_4074;
+ -- Log base 2 of e
+ constant MATH_LOG10_OF_E : REAL := 0.43429_44819_03251_82765;
+ -- Log base 10 of e
+ constant MATH_SQRT_2 : REAL := 1.41421_35623_73095_04880;
+ -- square root of 2
+ constant MATH_1_OVER_SQRT_2 : REAL := 0.70710_67811_86547_52440;
+ -- square root of 1/2
+ constant MATH_SQRT_PI : REAL := 1.77245_38509_05516_02730;
+ -- square root of pi
+ constant MATH_DEG_TO_RAD : REAL := 0.01745_32925_19943_29577;
+ -- Conversion factor from degree to radian
+ constant MATH_RAD_TO_DEG : REAL := 57.29577_95130_82320_87680;
+ -- Conversion factor from radian to degree
+
+ --
+ -- Function Declarations
+ --
+ function SIGN (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns 1.0 if X > 0.0; 0.0 if X = 0.0; -1.0 if X < 0.0
+ -- Special values:
+ -- None
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- ABS(SIGN(X)) <= 1.0
+ -- Notes:
+ -- None
+
+ function CEIL (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns smallest INTEGER value (as REAL) not less than X
+ -- Special values:
+ -- None
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- CEIL(X) is mathematically unbounded
+ -- Notes:
+ -- a) Implementations have to support at least the domain
+ -- ABS(X) < REAL(INTEGER'HIGH)
+
+ function FLOOR (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns largest INTEGER value (as REAL) not greater than X
+ -- Special values:
+ -- FLOOR(0.0) = 0.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- FLOOR(X) is mathematically unbounded
+ -- Notes:
+ -- a) Implementations have to support at least the domain
+ -- ABS(X) < REAL(INTEGER'HIGH)
+
+ function ROUND (X : in REAL) return REAL;
+ -- Purpose:
+ -- Rounds X to the nearest integer value (as real). If X is
+ -- halfway between two integers, rounding is away from 0.0
+ -- Special values:
+ -- ROUND(0.0) = 0.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- ROUND(X) is mathematically unbounded
+ -- Notes:
+ -- a) Implementations have to support at least the domain
+ -- ABS(X) < REAL(INTEGER'HIGH)
+
+ function TRUNC (X : in REAL) return REAL;
+ -- Purpose:
+ -- Truncates X towards 0.0 and returns truncated value
+ -- Special values:
+ -- TRUNC(0.0) = 0.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- TRUNC(X) is mathematically unbounded
+ -- Notes:
+ -- a) Implementations have to support at least the domain
+ -- ABS(X) < REAL(INTEGER'HIGH)
+
+ function "MOD" (X, Y : in REAL) return REAL;
+ -- Purpose:
+ -- Returns floating point modulus of X/Y, with the same sign as
+ -- Y, and absolute value less than the absolute value of Y, and
+ -- for some INTEGER value N the result satisfies the relation
+ -- X = Y*N + MOD(X,Y)
+ -- Special values:
+ -- None
+ -- Domain:
+ -- X in REAL; Y in REAL and Y /= 0.0
+ -- Error conditions:
+ -- Error if Y = 0.0
+ -- Range:
+ -- ABS(MOD(X,Y)) < ABS(Y)
+ -- Notes:
+ -- None
+
+ function REALMAX (X, Y : in REAL) return REAL;
+ -- Purpose:
+ -- Returns the algebraically larger of X and Y
+ -- Special values:
+ -- REALMAX(X,Y) = X when X = Y
+ -- Domain:
+ -- X in REAL; Y in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- REALMAX(X,Y) is mathematically unbounded
+ -- Notes:
+ -- None
+
+ function REALMIN (X, Y : in REAL) return REAL;
+ -- Purpose:
+ -- Returns the algebraically smaller of X and Y
+ -- Special values:
+ -- REALMIN(X,Y) = X when X = Y
+ -- Domain:
+ -- X in REAL; Y in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- REALMIN(X,Y) is mathematically unbounded
+ -- Notes:
+ -- None
+
+ procedure UNIFORM(variable SEED1, SEED2 : inout POSITIVE; variable X : out REAL);
+ -- Purpose:
+ -- Returns, in X, a pseudo-random number with uniform
+ -- distribution in the open interval (0.0, 1.0).
+ -- Special values:
+ -- None
+ -- Domain:
+ -- 1 <= SEED1 <= 2147483562; 1 <= SEED2 <= 2147483398
+ -- Error conditions:
+ -- Error if SEED1 or SEED2 outside of valid domain
+ -- Range:
+ -- 0.0 < X < 1.0
+ -- Notes:
+ -- a) The semantics for this function are described by the
+ -- algorithm published by Pierre L'Ecuyer in "Communications
+ -- of the ACM," vol. 31, no. 6, June 1988, pp. 742-774.
+ -- The algorithm is based on the combination of two
+ -- multiplicative linear congruential generators for 32-bit
+ -- platforms.
+ --
+ -- b) Before the first call to UNIFORM, the seed values
+ -- (SEED1, SEED2) have to be initialized to values in the range
+ -- [1, 2147483562] and [1, 2147483398] respectively. The
+ -- seed values are modified after each call to UNIFORM.
+ --
+ -- c) This random number generator is portable for 32-bit
+ -- computers, and it has a period of ~2.30584*(10**18) for each
+ -- set of seed values.
+ --
+ -- d) For information on spectral tests for the algorithm, refer
+ -- to the L'Ecuyer article.
+
+ function SQRT (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns square root of X
+ -- Special values:
+ -- SQRT(0.0) = 0.0
+ -- SQRT(1.0) = 1.0
+ -- Domain:
+ -- X >= 0.0
+ -- Error conditions:
+ -- Error if X < 0.0
+ -- Range:
+ -- SQRT(X) >= 0.0
+ -- Notes:
+ -- a) The upper bound of the reachable range of SQRT is
+ -- approximately given by:
+ -- SQRT(X) <= SQRT(REAL'HIGH)
+
+ function CBRT (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns cube root of X
+ -- Special values:
+ -- CBRT(0.0) = 0.0
+ -- CBRT(1.0) = 1.0
+ -- CBRT(-1.0) = -1.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- CBRT(X) is mathematically unbounded
+ -- Notes:
+ -- a) The reachable range of CBRT is approximately given by:
+ -- ABS(CBRT(X)) <= CBRT(REAL'HIGH)
+
+ function "**" (X : in INTEGER; Y : in REAL) return REAL;
+ -- Purpose:
+ -- Returns Y power of X ==> X**Y
+ -- Special values:
+ -- X**0.0 = 1.0; X /= 0
+ -- 0**Y = 0.0; Y > 0.0
+ -- X**1.0 = REAL(X); X >= 0
+ -- 1**Y = 1.0
+ -- Domain:
+ -- X > 0
+ -- X = 0 for Y > 0.0
+ -- X < 0 for Y = 0.0
+ -- Error conditions:
+ -- Error if X < 0 and Y /= 0.0
+ -- Error if X = 0 and Y <= 0.0
+ -- Range:
+ -- X**Y >= 0.0
+ -- Notes:
+ -- a) The upper bound of the reachable range for "**" is
+ -- approximately given by:
+ -- X**Y <= REAL'HIGH
+
+ function "**" (X : in REAL; Y : in REAL) return REAL;
+ -- Purpose:
+ -- Returns Y power of X ==> X**Y
+ -- Special values:
+ -- X**0.0 = 1.0; X /= 0.0
+ -- 0.0**Y = 0.0; Y > 0.0
+ -- X**1.0 = X; X >= 0.0
+ -- 1.0**Y = 1.0
+ -- Domain:
+ -- X > 0.0
+ -- X = 0.0 for Y > 0.0
+ -- X < 0.0 for Y = 0.0
+ -- Error conditions:
+ -- Error if X < 0.0 and Y /= 0.0
+ -- Error if X = 0.0 and Y <= 0.0
+ -- Range:
+ -- X**Y >= 0.0
+ -- Notes:
+ -- a) The upper bound of the reachable range for "**" is
+ -- approximately given by:
+ -- X**Y <= REAL'HIGH
+
+ function EXP (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns e**X; where e = MATH_E
+ -- Special values:
+ -- EXP(0.0) = 1.0
+ -- EXP(1.0) = MATH_E
+ -- EXP(-1.0) = MATH_1_OVER_E
+ -- EXP(X) = 0.0 for X <= -LOG(REAL'HIGH)
+ -- Domain:
+ -- X in REAL such that EXP(X) <= REAL'HIGH
+ -- Error conditions:
+ -- Error if X > LOG(REAL'HIGH)
+ -- Range:
+ -- EXP(X) >= 0.0
+ -- Notes:
+ -- a) The usable domain of EXP is approximately given by:
+ -- X <= LOG(REAL'HIGH)
+
+ function LOG (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns natural logarithm of X
+ -- Special values:
+ -- LOG(1.0) = 0.0
+ -- LOG(MATH_E) = 1.0
+ -- Domain:
+ -- X > 0.0
+ -- Error conditions:
+ -- Error if X <= 0.0
+ -- Range:
+ -- LOG(X) is mathematically unbounded
+ -- Notes:
+ -- a) The reachable range of LOG is approximately given by:
+ -- LOG(0+) <= LOG(X) <= LOG(REAL'HIGH)
+
+ function LOG2 (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns logarithm base 2 of X
+ -- Special values:
+ -- LOG2(1.0) = 0.0
+ -- LOG2(2.0) = 1.0
+ -- Domain:
+ -- X > 0.0
+ -- Error conditions:
+ -- Error if X <= 0.0
+ -- Range:
+ -- LOG2(X) is mathematically unbounded
+ -- Notes:
+ -- a) The reachable range of LOG2 is approximately given by:
+ -- LOG2(0+) <= LOG2(X) <= LOG2(REAL'HIGH)
+
+ function LOG10 (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns logarithm base 10 of X
+ -- Special values:
+ -- LOG10(1.0) = 0.0
+ -- LOG10(10.0) = 1.0
+ -- Domain:
+ -- X > 0.0
+ -- Error conditions:
+ -- Error if X <= 0.0
+ -- Range:
+ -- LOG10(X) is mathematically unbounded
+ -- Notes:
+ -- a) The reachable range of LOG10 is approximately given by:
+ -- LOG10(0+) <= LOG10(X) <= LOG10(REAL'HIGH)
+
+ function LOG (X : in REAL; BASE : in REAL) return REAL;
+ -- Purpose:
+ -- Returns logarithm base BASE of X
+ -- Special values:
+ -- LOG(1.0, BASE) = 0.0
+ -- LOG(BASE, BASE) = 1.0
+ -- Domain:
+ -- X > 0.0
+ -- BASE > 0.0
+ -- BASE /= 1.0
+ -- Error conditions:
+ -- Error if X <= 0.0
+ -- Error if BASE <= 0.0
+ -- Error if BASE = 1.0
+ -- Range:
+ -- LOG(X, BASE) is mathematically unbounded
+ -- Notes:
+ -- a) When BASE > 1.0, the reachable range of LOG is
+ -- approximately given by:
+ -- LOG(0+, BASE) <= LOG(X, BASE) <= LOG(REAL'HIGH, BASE)
+ -- b) When 0.0 < BASE < 1.0, the reachable range of LOG is
+ -- approximately given by:
+ -- LOG(REAL'HIGH, BASE) <= LOG(X, BASE) <= LOG(0+, BASE)
+
+ function SIN (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns sine of X; X in radians
+ -- Special values:
+ -- SIN(X) = 0.0 for X = k*MATH_PI, where k is an INTEGER
+ -- SIN(X) = 1.0 for X = (4*k+1)*MATH_PI_OVER_2, where k is an
+ -- INTEGER
+ -- SIN(X) = -1.0 for X = (4*k+3)*MATH_PI_OVER_2, where k is an
+ -- INTEGER
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- ABS(SIN(X)) <= 1.0
+ -- Notes:
+ -- a) For larger values of ABS(X), degraded accuracy is allowed.
+
+ function COS (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns cosine of X; X in radians
+ -- Special values:
+ -- COS(X) = 0.0 for X = (2*k+1)*MATH_PI_OVER_2, where k is an
+ -- INTEGER
+ -- COS(X) = 1.0 for X = (2*k)*MATH_PI, where k is an INTEGER
+ -- COS(X) = -1.0 for X = (2*k+1)*MATH_PI, where k is an INTEGER
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- ABS(COS(X)) <= 1.0
+ -- Notes:
+ -- a) For larger values of ABS(X), degraded accuracy is allowed.
+
+ function TAN (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns tangent of X; X in radians
+ -- Special values:
+ -- TAN(X) = 0.0 for X = k*MATH_PI, where k is an INTEGER
+ -- Domain:
+ -- X in REAL and
+ -- X /= (2*k+1)*MATH_PI_OVER_2, where k is an INTEGER
+ -- Error conditions:
+ -- Error if X = ((2*k+1) * MATH_PI_OVER_2), where k is an
+ -- INTEGER
+ -- Range:
+ -- TAN(X) is mathematically unbounded
+ -- Notes:
+ -- a) For larger values of ABS(X), degraded accuracy is allowed.
+
+ function ARCSIN (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns inverse sine of X
+ -- Special values:
+ -- ARCSIN(0.0) = 0.0
+ -- ARCSIN(1.0) = MATH_PI_OVER_2
+ -- ARCSIN(-1.0) = -MATH_PI_OVER_2
+ -- Domain:
+ -- ABS(X) <= 1.0
+ -- Error conditions:
+ -- Error if ABS(X) > 1.0
+ -- Range:
+ -- ABS(ARCSIN(X) <= MATH_PI_OVER_2
+ -- Notes:
+ -- None
+
+ function ARCCOS (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns inverse cosine of X
+ -- Special values:
+ -- ARCCOS(1.0) = 0.0
+ -- ARCCOS(0.0) = MATH_PI_OVER_2
+ -- ARCCOS(-1.0) = MATH_PI
+ -- Domain:
+ -- ABS(X) <= 1.0
+ -- Error conditions:
+ -- Error if ABS(X) > 1.0
+ -- Range:
+ -- 0.0 <= ARCCOS(X) <= MATH_PI
+ -- Notes:
+ -- None
+
+ function ARCTAN (Y : in REAL) return REAL;
+ -- Purpose:
+ -- Returns the value of the angle in radians of the point
+ -- (1.0, Y), which is in rectangular coordinates
+ -- Special values:
+ -- ARCTAN(0.0) = 0.0
+ -- Domain:
+ -- Y in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- ABS(ARCTAN(Y)) <= MATH_PI_OVER_2
+ -- Notes:
+ -- None
+
+ function ARCTAN (Y : in REAL; X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns the principal value of the angle in radians of
+ -- the point (X, Y), which is in rectangular coordinates
+ -- Special values:
+ -- ARCTAN(0.0, X) = 0.0 if X > 0.0
+ -- ARCTAN(0.0, X) = MATH_PI if X < 0.0
+ -- ARCTAN(Y, 0.0) = MATH_PI_OVER_2 if Y > 0.0
+ -- ARCTAN(Y, 0.0) = -MATH_PI_OVER_2 if Y < 0.0
+ -- Domain:
+ -- Y in REAL
+ -- X in REAL, X /= 0.0 when Y = 0.0
+ -- Error conditions:
+ -- Error if X = 0.0 and Y = 0.0
+ -- Range:
+ -- -MATH_PI < ARCTAN(Y,X) <= MATH_PI
+ -- Notes:
+ -- None
+
+ function SINH (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns hyperbolic sine of X
+ -- Special values:
+ -- SINH(0.0) = 0.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- SINH(X) is mathematically unbounded
+ -- Notes:
+ -- a) The usable domain of SINH is approximately given by:
+ -- ABS(X) <= LOG(REAL'HIGH)
+
+
+ function COSH (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns hyperbolic cosine of X
+ -- Special values:
+ -- COSH(0.0) = 1.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- COSH(X) >= 1.0
+ -- Notes:
+ -- a) The usable domain of COSH is approximately given by:
+ -- ABS(X) <= LOG(REAL'HIGH)
+
+ function TANH (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns hyperbolic tangent of X
+ -- Special values:
+ -- TANH(0.0) = 0.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- ABS(TANH(X)) <= 1.0
+ -- Notes:
+ -- None
+
+ function ARCSINH (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns inverse hyperbolic sine of X
+ -- Special values:
+ -- ARCSINH(0.0) = 0.0
+ -- Domain:
+ -- X in REAL
+ -- Error conditions:
+ -- None
+ -- Range:
+ -- ARCSINH(X) is mathematically unbounded
+ -- Notes:
+ -- a) The reachable range of ARCSINH is approximately given by:
+ -- ABS(ARCSINH(X)) <= LOG(REAL'HIGH)
+
+ function ARCCOSH (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns inverse hyperbolic cosine of X
+ -- Special values:
+ -- ARCCOSH(1.0) = 0.0
+ -- Domain:
+ -- X >= 1.0
+ -- Error conditions:
+ -- Error if X < 1.0
+ -- Range:
+ -- ARCCOSH(X) >= 0.0
+ -- Notes:
+ -- a) The upper bound of the reachable range of ARCCOSH is
+ -- approximately given by: ARCCOSH(X) <= LOG(REAL'HIGH)
+
+ function ARCTANH (X : in REAL) return REAL;
+ -- Purpose:
+ -- Returns inverse hyperbolic tangent of X
+ -- Special values:
+ -- ARCTANH(0.0) = 0.0
+ -- Domain:
+ -- ABS(X) < 1.0
+ -- Error conditions:
+ -- Error if ABS(X) >= 1.0
+ -- Range:
+ -- ARCTANH(X) is mathematically unbounded
+ -- Notes:
+ -- a) The reachable range of ARCTANH is approximately given by:
+ -- ABS(ARCTANH(X)) < LOG(REAL'HIGH)
+
+end package MATH_REAL;