glibc_random.vhdl

   1 library ieee;
   2 use ieee.std_logic_1164.all;
   3 use ieee.numeric_std.all;
   4
   5 library work;
   6 use work.glibc_random_helpers.all;
   7
   8 package glibc_random is
   9     function pseudorand(a: integer) return std_ulogic_vector;
  10     function pseudorand1 return std_ulogic;
  11 end package glibc_random;
  12
  13 package body glibc_random is
  14     function pseudorand(a: integer) return std_ulogic_vector is
  15         variable tmp1, tmp2, tmp3, tmp4: std_ulogic_vector(31 downto 0);
  16         variable ret: std_ulogic_vector(63 downto 0);
  17     begin
  18         tmp1 := std_ulogic_vector(to_unsigned(random, 32));
  19         tmp2 := std_ulogic_vector(to_unsigned(random, 32));
  20         if a <= 32 then
  21             ret := tmp1 & tmp2;
  22         else
  23             tmp3 := std_ulogic_vector(to_unsigned(random, 32));
  24             tmp4 := std_ulogic_vector(to_unsigned(random, 32));
  25
  26             ret := tmp1(15 downto 0) & tmp2(15 downto 0) & tmp3(15 downto 0) & tmp4(15 downto 0);
  27         end if;
  28
  29         return ret((a-1) downto 0);
  30     end;
  31
  32     function pseudorand1 return std_ulogic is
  33         variable tmp: std_ulogic_vector(31 downto 0);
  34     begin
  35         tmp := std_ulogic_vector(to_unsigned(random, 32));
  36         return tmp(0);
  37     end;
  38 end package body glibc_random;