1
2-- Copyright (C) 1996 Morgan Kaufmann Publishers, Inc
3
4-- This file is part of VESTs (Vhdl tESTs).
5
6-- VESTs is free software; you can redistribute it and/or modify it
7-- under the terms of the GNU General Public License as published by the
8-- Free Software Foundation; either version 2 of the License, or (at
9-- your option) any later version.
10
11-- VESTs is distributed in the hope that it will be useful, but WITHOUT
12-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13-- FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14-- for more details.
15
16-- You should have received a copy of the GNU General Public License
17-- along with VESTs; if not, write to the Free Software Foundation,
18-- Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19
20-- ---------------------------------------------------------------------
21--
22-- $Id: math_real.vhd,v 1.2 2001-10-26 16:29:37 paw Exp $
23-- $Revision: 1.2 $
24--
25-- ---------------------------------------------------------------------
26
27---------------------------------------------------------------
28--
29-- This source file may be used and distributed without restriction.
30-- No declarations or definitions shall be included in this package.
31--
32--   ****************************************************************
33--   *                                                              *
34--   *                      W A R N I N G		 	    *
35--   *								    *
36--   *   This DRAFT version IS NOT endorsed or approved by IEEE     *
37--   *								    *
38--   ****************************************************************
39--
40-- Title:    PACKAGE MATH_REAL
41--
42-- Library:  This package shall be compiled into a library
43--           symbolically named IEEE.
44--
45-- Purpose:  VHDL declarations for mathematical package MATH_REAL
46--	     which contains common real constants, common real
47--	     functions, and real trascendental functions.
48--
49-- Author:   Based on work by IEEE VHDL Math Package Study Group
50--
51-- Notes:
52-- 	The package body shall be considered the formal definition of
53-- 	the semantics of this package. Tool developers may choose to implement
54-- 	the package body in the most efficient manner available to them.
55--
56-- History:
57--	Version 0.4		JAT	4/15/93
58-------------------------------------------------------------
59Library IEEE;
60
61Package MATH_REAL is
62--synopsys synthesis_off
63
64  constant  MATH_E :         real := 2.71828_18284_59045_23536;
65                                        -- value of e
66  constant  MATH_1_E:        real := 0.36787_94411_71442_32160;
67                                        -- value of 1/e
68  constant  MATH_PI :        real := 3.14159_26535_89793_23846;
69                                        -- value of pi
70  constant  MATH_1_PI :      real := 0.31830_98861_83790_67154;
71                                        -- value of 1/pi
72  constant  MATH_LOG_OF_2:   real := 0.69314_71805_59945_30942;
73                                        -- natural log of 2
74  constant  MATH_LOG_OF_10:  real := 2.30258_50929_94045_68402;
75                                        -- natural log of10
76  constant  MATH_LOG2_OF_E:  real := 1.44269_50408_88963_4074;
77                                        -- log base 2 of e
78  constant  MATH_LOG10_OF_E: real := 0.43429_44819_03251_82765;
79                                        -- log base 10 of e
80  constant  MATH_SQRT2:      real := 1.41421_35623_73095_04880;
81                                        -- sqrt of 2
82  constant  MATH_SQRT1_2:    real := 0.70710_67811_86547_52440;
83                                        -- sqrt of 1/2
84  constant  MATH_SQRT_PI:    real := 1.77245_38509_05516_02730;
85                                        -- sqrt of pi
86  constant  MATH_DEG_TO_RAD: real := 0.01745_32925_19943_29577;
87  -- conversion factor from degree to radian
88  constant  MATH_RAD_TO_DEG: real := 57.29577_95130_82320_87685;
89  -- conversion factor from radian to degree
90
91  --
92  -- attribute for functions whose implementation is foreign (C native)
93  --
94  -- attribute FOREIGN: string;  -- predefined attribute in VHDL-1992
95  --
96
97  function SIGN (X: real ) return real;
98  -- returns 1.0 if X > 0.0; 0.0 if X == 0.0; -1.0 if X < 0.0
99
100  function CEIL (X : real ) return real;
101  -- returns smallest integer value (as real) not less than X
102
103  function FLOOR (X : real ) return real;
104  -- returns largest integer value (as real) not greater than X
105
106  function ROUND (X : real ) return real;
107  -- returns FLOOR(X + 0.5) if X > 0.0;
108  -- return CEIL(X - 0.5) if X < 0.0
109
110  function FMAX (X, Y : real ) return real;
111  -- returns the algebraically larger of X and Y
112
113  function FMIN (X, Y : real ) return real;
114  -- returns the algebraically smaller of X and Y
115
116  function SRAND (seed: in integer ) return integer;
117  -- attribute FOREIGN of SRAND: function is "C_NATIVE";
118  -- for VHDL-1992 standard
119  --
120  -- sets value of seed for sequence of pseudo-random numbers.
121  -- returns the value of the seed.
122  -- It uses the native C function srand().
123
124  function RAND return integer;
125  -- attribute FOREIGN of RAND: function is "C_NATIVE";
126  -- for VHDL-1992 standard
127  --
128  -- returns an integer pseudo-random number with uniform distribution.
129  -- It uses the native C function rand().
130  -- Seed for the sequence is initialized with the
131  -- SRAND() function and value of the seed is changed every
132  -- time SRAND() is called,  but it is not visible.
133  -- The range of generated values is platform dependent.
134
135  function GET_RAND_MAX return integer;
136  -- attribute FOREIGN of GET_RAND_MAX: function is "C_NATIVE";
137  -- for VHDL-1992 standard
138  --
139  -- returns the upper bound of the range of the
140  -- pseudo-random numbers generated by  RAND().
141  -- The support for this function is platform dependent.
142  -- It may not be available in some platforms.
143  -- Note: the value of (RAND() / GET_RAND_MAX()) is a
144  --       pseudo-random number distributed between 0 & 1.
145
146  function SQRT (X : real ) return real;
147  -- returns square root of X;  X >= 0.0
148
149  function CBRT (X : real ) return real;
150  -- returns cube root of X
151
152  function "**" (X : integer; Y : real) return real;
153  -- returns Y power of X ==>  X**Y;
154  -- error if X = 0 and Y <= 0.0
155  -- error if X < 0 and Y does not have an integral value
156
157  function "**" (X : real; Y : real) return real;
158  -- returns Y power of X ==>  X**Y;
159  -- error if X = 0.0 and Y <= 0.0
160  -- error if X < 0.0 and Y does not have an integral value
161
162  function EXP  (X : real ) return real;
163  -- returns e**X; where e = MATH_E
164
165  function LOG (X : real ) return real;
166  -- returns natural logarithm of X; X > 0
167
168  function LOG (BASE: positive; X : real) return real;
169  -- returns logarithm base BASE of X; X > 0
170
171  function  SIN (X : real ) return real;
172  -- returns sin X; X in radians
173
174  function  COS ( X : real ) return real;
175  -- returns cos X; X in radians
176
177  function  TAN (X : real ) return real;
178  -- returns tan X; X in radians
179  -- X /= ((2k+1) * PI/2), where k is an integer
180
181  function  ASIN (X : real ) return real;
182  -- returns  -PI/2 < asin X < PI/2; | X | <= 1.0
183
184  function  ACOS (X : real ) return real;
185  -- returns  0 < acos X < PI; | X | <= 1.0
186
187  function  ATAN (X : real) return real;
188  -- returns  -PI/2 < atan X < PI/2
189
190  function  ATAN2 (X : real; Y : real) return real;
191  -- returns  atan (X/Y); -PI < atan2(X,Y) < PI; Y /= 0.0
192
193  function SINH (X : real) return real;
194  -- hyperbolic sine; returns (e**X - e**(-X))/2
195
196  function  COSH (X : real) return real;
197  -- hyperbolic cosine; returns (e**X + e**(-X))/2
198
199  function  TANH (X : real) return real;
200  -- hyperbolic tangent; -- returns (e**X - e**(-X))/(e**X + e**(-X))
201
202  function ASINH (X : real) return real;
203  -- returns ln( X + sqrt( X**2 + 1))
204
205  function ACOSH (X : real) return real;
206  -- returns ln( X + sqrt( X**2 - 1));   X >= 1.0
207
208  function ATANH (X : real) return real;
209  -- returns (ln( (1 + X)/(1 - X)))/2 ; | X | < 1.0
210
211--synopsys synthesis_on
212end  MATH_REAL;
213