Using real data types in VHDL

 1 library IEEE;
 2 use IEEE.STD_LOGIC_1164.ALL;
 3 use IEEE.MATH_REAL.ALL;
 4 
 5 entity real_demo is
 6 end real_demo;
 7 
 8 architecture Behavioral of real_demo is
 9 
10 --signals declared with the REAL data type.
11 --MATH_PI is a constant defined in the math_real package.
12 signal X : real := -MATH_PI/3.0; --A real variable X, initialized to pi/3(60 degreee).
13 signal sign_result,ceil_result,floor_result,round_result,trunc_result : real := 0.0;
14 signal max,min,root,cube,power1,power2,exp_result : real := 0.0;
15 signal log_result,log2_result,log10_result,log_result2,sine,cosine,tangent : real := 0.0;
16 signal sin_inv,cos_inv,tan_inv,sin_hyp,cos_hyp,tan_hyp : real := 0.0;
17 signal inv_sin_hyp,inv_cos_hyp,inv_tan_hyp : real := 0.0;
18 
19 begin
20 
21 process
22 begin
23 
24 sign_result <= SIGN(X);  --sign of X
25 ceil_result <= CEIL(X); --smallest integer value not less than X
26 floor_result <= FLOOR(X); --largest integer value not greater than X
27 round_result <= ROUND(X); --round to the nearest integer.
28 trunc_result <= TRUNC(X); --truncation.
29 max <= REALMAX(4.5,4.6); --return the maximum
30 min <= REALMIN(2.3,3.2); --return the minimum
31 root <= SQRT(4.0);  --square root
32 cube <= CBRT(64.0); --cube root
33 power1 <= 2**3.0; --power of an integer
34 power2 <= 3.0**3.0; --power of a real
35 exp_result <= EXP(1.0); --returns e**X.
36 log_result <= LOG(2.73); --natural logarithm
37 log2_result <= LOG2(16.0); --log to the base 2.
38 log10_result <= LOG10(100.0); --log to the base 10.
39 log_result2 <= LOG(27.0,3.0); --log to the given base.
40 sine <= SIN(X); --sine of the given angle(in rad)
41 cosine <= COS(X);--cosine of the given angle(in rad)
42 tangent <= TAN(X);--tangent of the given angle(in rad)
43 sin_inv <= ARCSIN(SIN(X)); --sine inverse.
44 cos_inv <= ARCCOS(COS(X)); --cosine inverse.
45 tan_inv <= ARCTAN(TAN(X)); --tangent inverse.
46 sin_hyp <= SINH(X); --Hyperbolic sine
47 cos_hyp <= COSH(X); --Hyperbolic cosine.
48 tan_hyp <= TANH(X); --Hyperbolic tangent.
49 inv_sin_hyp <= ARCSINH(SINH(X)); --Inverse hyperbolic sine.
50 inv_cos_hyp <= ARCCOSH(COSH(X)); --Inverse hyperbolic cosine.
51 inv_tan_hyp <= ARCTANH(TANH(X)); --Inverse hyperbolic tangent.
52 wait;
53 
54 end process;    
55 
56 end Behavioral;