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Diffstat (limited to 'libraries/ieee/math_real.vhdl')
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diff --git a/libraries/ieee/math_real.vhdl b/libraries/ieee/math_real.vhdl new file mode 100644 index 0000000..c70d216 --- /dev/null +++ b/libraries/ieee/math_real.vhdl @@ -0,0 +1,223 @@ +------------------------------------------------------------------------ +-- +-- This source file may be used and distributed without restriction. +-- No declarations or definitions shall be added to this package. +-- This package cannot be sold or distributed for profit. +-- +-- **************************************************************** +-- * * +-- * W A R N I N G * +-- * * +-- * This DRAFT version IS NOT endorsed or approved by IEEE * +-- * * +-- **************************************************************** +-- +-- Title: PACKAGE MATH_REAL +-- +-- Library: This package shall be compiled into a library +-- symbolically named IEEE. +-- +-- Purpose: VHDL declarations for mathematical package MATH_REAL +-- which contains common real constants, common real +-- functions, and real trascendental functions. +-- +-- Author: IEEE VHDL Math Package Study Group +-- +-- Notes: +-- The package body shall be considered the formal definition of +-- the semantics of this package. Tool developers may choose to implement +-- the package body in the most efficient manner available to them. +-- +-- History: +-- Version 0.1 (Strawman) Jose A. Torres 6/22/92 +-- Version 0.2 Jose A. Torres 1/15/93 +-- Version 0.3 Jose A. Torres 4/13/93 +-- Version 0.4 Jose A. Torres 4/19/93 +-- Version 0.5 Jose A. Torres 4/20/93 Added RANDOM() +-- Version 0.6 Jose A. Torres 4/23/93 Renamed RANDOM as +-- UNIFORM. Modified +-- rights banner. +-- Version 0.7 Jose A. Torres 5/28/93 Rev up for compatibility +-- with package body. +-- +-- GHDL history +-- 2005-04-07 Initial version. +-- 2005-09-01 Some PI constants added. +------------------------------------------------------------- +Library IEEE; + +Package MATH_REAL is + + -- + -- commonly used constants + -- + constant MATH_E : real := 2.71828_18284_59045_23536; -- e + constant MATH_1_OVER_E : real := 0.36787_94411_71442_32160; -- 1/e + constant MATH_PI : real := 3.14159_26535_89793_23846; -- pi + constant MATH_2_PI : real := 2.0 * MATH_PI; -- 2 * pi + constant MATH_1_OVER_PI : real := 0.31830_98861_83790_67154; -- 1/pi + constant MATH_PI_OVER_2 : real := 1.57079_63267_94896_61923; -- pi / 2 + constant MATH_PI_OVER_4 : real := 0.78539_81633_97448_30962; -- pi / 4 + 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 of10 + 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_SQRT2: real := 1.41421_35623_73095_04880; + -- sqrt of 2 + constant MATH_SQRT1_2: real := 0.70710_67811_86547_52440; + -- sqrt of 1/2 + constant MATH_SQRT_PI: real := 1.77245_38509_05516_02730; + -- sqrt 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_87685; + -- conversion factor from radian to degree + + -- + -- function declarations + -- + function SIGN (X: real ) return real; + -- returns 1.0 if X > 0.0; 0.0 if X == 0.0; -1.0 if X < 0.0 + + function CEIL (X : real ) return real; + attribute foreign of ceil : function is "VHPIDIRECT ceil"; + -- returns smallest integer value (as real) not less than X + + function FLOOR (X : real ) return real; + attribute foreign of floor : function is "VHPIDIRECT floor"; + -- returns largest integer value (as real) not greater than X + + function ROUND (X : real ) return real; + attribute foreign of round : function is "VHPIDIRECT round"; + -- returns integer FLOOR(X + 0.5) if X > 0; + -- return integer CEIL(X - 0.5) if X < 0 + + function FMAX (X, Y : real ) return real; + attribute foreign of fmax : function is "VHPIDIRECT fmax"; + -- returns the algebraically larger of X and Y + + function FMIN (X, Y : real ) return real; + attribute foreign of fmin : function is "VHPIDIRECT fmin"; + -- returns the algebraically smaller of X and Y + + procedure UNIFORM (variable Seed1,Seed2:inout integer; variable X:out real); + -- returns a pseudo-random number with uniform distribution in the + -- interval (0.0, 1.0). + -- Before the first call to UNIFORM, the seed values (Seed1, Seed2) must + -- be initialized to values in the range [1, 2147483562] and + -- [1, 2147483398] respectively. The seed values are modified after + -- each call to UNIFORM. + -- This random number generator is portable for 32-bit computers, and + -- it has period ~2.30584*(10**18) for each set of seed values. + -- + -- For VHDL-1992, the seeds will be global variables, functions to + -- initialize their values (INIT_SEED) will be provided, and the UNIFORM + -- procedure call will be modified accordingly. + + function SRAND (seed: in integer ) return integer; + attribute foreign of srand : function is "VHPIDIRECT srand"; + -- + -- sets value of seed for sequence of + -- pseudo-random numbers. + -- It uses the foreign native C function srand(). + + function RAND return integer; + attribute foreign of rand : function is "VHPIDIRECT rand"; + -- + -- returns an integer pseudo-random number with uniform distribution. + -- It uses the foreign native C function rand(). + -- Seed for the sequence is initialized with the + -- SRAND() function and value of the seed is changed every + -- time SRAND() is called, but it is not visible. + -- The range of generated values is platform dependent. + + function GET_RAND_MAX return integer; + -- + -- returns the upper bound of the range of the + -- pseudo-random numbers generated by RAND(). + -- The support for this function is platform dependent, and + -- it uses foreign native C functions or constants. + -- It may not be available in some platforms. + -- Note: the value of (RAND() / GET_RAND_MAX()) is a + -- pseudo-random number distributed between 0 & 1. + + function SQRT (X : real ) return real; + -- returns square root of X; X >= 0 + + function CBRT (X : real ) return real; + attribute foreign of cbrt : function is "VHPIDIRECT cbrt"; + -- returns cube root of X + + function "**" (X : integer; Y : real) return real; + -- returns Y power of X ==> X**Y; + -- error if X = 0 and Y <= 0.0 + -- error if X < 0 and Y does not have an integer value + + function "**" (X : real; Y : real) return real; + -- returns Y power of X ==> X**Y; + -- error if X = 0.0 and Y <= 0.0 + -- error if X < 0.0 and Y does not have an integer value + + function EXP (X : real ) return real; + attribute foreign of exp : function is "VHPIDIRECT exp"; + -- returns e**X; where e = MATH_E + + function LOG (X : real ) return real; + -- returns natural logarithm of X; X > 0 + + function LOG (BASE: positive; X : real) return real; + -- returns logarithm base BASE of X; X > 0 + + function SIN (X : real ) return real; + attribute foreign of sin : function is "VHPIDIRECT sin"; + -- returns sin X; X in radians + + function COS ( X : real ) return real; + attribute foreign of cos : function is "VHPIDIRECT cos"; + -- returns cos X; X in radians + + function TAN (X : real ) return real; + attribute foreign of tan : function is "VHPIDIRECT tan"; + -- returns tan X; X in radians + -- X /= ((2k+1) * PI/2), where k is an integer + + function ASIN (X : real ) return real; + -- returns -PI/2 < asin X < PI/2; | X | <= 1 + + function ACOS (X : real ) return real; + -- returns 0 < acos X < PI; | X | <= 1 + + function ATAN (X : real) return real; + attribute foreign of atan : function is "VHPIDIRECT atan"; + -- returns -PI/2 < atan X < PI/2 + + function ATAN2 (X : real; Y : real) return real; + -- returns atan (X/Y); -PI < atan2(X,Y) < PI; Y /= 0.0 + + function SINH (X : real) return real; + attribute foreign of sinh : function is "VHPIDIRECT sinh"; + -- hyperbolic sine; returns (e**X - e**(-X))/2 + + function COSH (X : real) return real; + attribute foreign of cosh : function is "VHPIDIRECT cosh"; + -- hyperbolic cosine; returns (e**X + e**(-X))/2 + + function TANH (X : real) return real; + attribute foreign of tanh : function is "VHPIDIRECT tanh"; + -- hyperbolic tangent; -- returns (e**X - e**(-X))/(e**X + e**(-X)) + + function ASINH (X : real) return real; + attribute foreign of asinh : function is "VHPIDIRECT asinh"; + -- returns ln( X + sqrt( X**2 + 1)) + + function ACOSH (X : real) return real; + -- returns ln( X + sqrt( X**2 - 1)); X >= 1 + + function ATANH (X : real) return real; + -- returns (ln( (1 + X)/(1 - X)))/2 ; | X | < 1 + +end MATH_REAL; |