Hi,

Here is a code that I wrote for random numbers between A and minus A.



architecture random of random_num is

constant K : real := 1.3806503e-23;
signal Vth_op: real := 0.0;
signal rand: real := 0.0;
signal clk : bit :='0';

entity ... is...
end entity;

architecture ideal of .... is

signal rand1,rand2: real := 0.0;
signal clk : bit :='0';

begin
     clk <= not clk after Tshrn;
     process
     variable unf : real;
     variable seed1:integer := 2;
     variable seed2:integer := 123123123;
     begin
     wait on clk;
     Uniform(seed1,seed2,unf);
     rand1 <= ROUND(unf*10.0);
               --Multiply unf by 10 to obtain integer
     end process;
     break on rand1;
               process
     variable unf : real;
     variable seed1:integer := 2;
     variable seed2:integer := 123123123;
     begin
     wait on clk;
     Uniform(seed1,seed2,unf);
     rand2 <= unf;
     end process;
     break on rand2;

   between_A_n_minusA == ((-1.0)**rand1)*rand2*A
end random;

This code may be freely distributed, I create it for a  course project. Hope it helps.

gEoRgiE