Subversion Repositories rng_lib

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----                                                              ----

---- Testbench for Rand number generator library.                 ----

----                                                              ----

---- This file is part of the Random Number Generator project     ----

---- http://www.opencores.org/cores/rng_lib/                      ----

----                                                              ----

---- Description                                                  ----

---- The test bench will generate 10000 random numbers from each  ----

---- distribution and do a simple plot of the distributions.      ----

----                                                              ----

---- To Do:                                                       ----

---- -                                                            ----

----                                                              ----

---- Author(s):                                                   ----

---- - Geir Drange, gedra@opencores.org                           ----

----                                                              ----

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----                                                              ----

---- Copyright (C) 2004 Authors and OPENCORES.ORG                 ----

----                                                              ----

---- This source file may be used and distributed without         ----

---- restriction provided that this copyright statement is not    ----

---- removed from the file and that any derivative work contains  ----

---- the original copyright notice and the associated disclaimer. ----

----                                                              ----

---- This source file is free software; you can redistribute it   ----

---- and/or modify it under the terms of the GNU General          ----

---- Public License as published by the Free Software Foundation; ----

---- either version 2.0 of the License, or (at your option) any   ----

---- later version.                                               ----

----                                                              ----

---- This source is distributed in the hope that it will be       ----

---- useful, but WITHOUT ANY WARRANTY; without even the implied   ----

---- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ----

---- PURPOSE. See the GNU General Public License for more details.----

----                                                              ----

---- You should have received a copy of the GNU General           ----

---- Public License along with this source; if not, download it   ----

---- from http://www.gnu.org/licenses/gpl.txt                     ----

----                                                              ----

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--

-- CVS Revision History

--

-- $Log: not supported by cvs2svn $

-- Revision 1.1  2004/09/28 15:12:52  gedra

-- Test bench for random numbers.

--

--

--

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use std.textio.all;

use work.rng_lib.all;

entity tb_rng is

end tb_rng;

architecture behav of tb_rng is

   constant BIN_COUNT   : integer := 15;

   constant PLOT_HEIGHT : real    := 40.0;

   constant RAND_COUNT  : integer := 10000;

   type rand_array is array (0 to RAND_COUNT - 1) of real;  -- array used for plot

   type bin_array is array (0 to BIN_COUNT - 1) of integer;

-- Plot a distribution of the numbers that are between lo,hi values

   impure function plot_dist (numbs : rand_array; lo, hi : real) return integer is

      variable bins             : bin_array;

      variable bin_size, height : real;

      variable idx, max         : integer;

      variable bar              : line;

   begin

      -- reset bins

      for i in 0 to BIN_COUNT - 1 loop

         bins(i) := 0;

      end loop;

      -- sort numbers into bins

      bin_size := (hi - lo) / real(BIN_COUNT);

      for i in 0 to RAND_COUNT - 1 loop

         if numbs(i) > lo and numbs(i) < hi then

            idx := integer(((numbs(i) - lo) / bin_size) - 0.5);

            if idx > BIN_COUNT - 1 then

               idx := BIN_COUNT - 1;

            elsif idx < 0 then

               idx := 0;

            end if;

            bins(idx) := bins(idx) + 1;

         end if;

      end loop;

      -- find largest bin

      max := 0;

      for i in 0 to BIN_COUNT - 1 loop

         if bins(i) > max then

            max := bins(i);

         end if;

      end loop;

      -- plot bins

      for i in 0 to BIN_COUNT - 1 loop

         height := PLOT_HEIGHT * real(bins(i)) / real(max);

         for j in 1 to integer(height) loop

            write(bar, string'("*"));

         end loop;

         writeline(OUTPUT, bar);

      end loop;

      return 0;

   end plot_dist;

begin

   p1 : process

      variable r_uni, r_gauss, r_exp : rand_var;

      variable r_poisson             : rand_var;

      variable txt                   : line;

      variable a                     : integer;

      variable numbs                 : rand_array;

   begin

      -- Test the uniform distribution

      r_uni := init_uniform(0, 0, 0, 0.0, 10.0);     -- range 0 to 10

      t1 : for i in 0 to RAND_COUNT - 1 loop

         r_uni    := rand(r_uni);

         numbs(i) := r_uni.rnd;

      end loop t1;

      write(txt, string'("Uniform distribution:"));

      writeline(OUTPUT, txt);

      a       := plot_dist (numbs, 0.0, 10.0);

      -- Test the gaussian distribution

      r_gauss := init_gaussian(0, 0, 0, 0.0, 10.0);  -- mean=0, stdev=10

      t2 : for i in 0 to RAND_COUNT - 1 loop

         r_gauss  := rand(r_gauss);

         numbs(i) := r_gauss.rnd;

      end loop t2;

      write(txt, string'("Gaussian distribution:"));

      writeline(OUTPUT, txt);

      a     := plot_dist (numbs, -20.0, 20.0);

      -- Test the exponential distribution

      r_exp := init_exponential(0, 0, 0, 10.0);      -- mean=10

      t3 : for i in 0 to RAND_COUNT - 1 loop

         r_exp    := rand(r_exp);

         numbs(i) := r_exp.rnd;

      end loop t3;

      write(txt, string'("Exponential distribution:"));

      writeline(OUTPUT, txt);

      a := plot_dist (numbs, 0.0, 20.0);

      wait for 1 ns;

      report "End of simulation! (ignore this failure)"

         severity failure;

      wait;

   end process p1;

end behav;