utils.vhdl

   1 library ieee;
   2 use ieee.std_logic_1164.all;
   3 use ieee.numeric_std.all;
   4
   5 package utils is
   6
   7     function log2(i : natural) return integer;
   8     function ispow2(i : integer) return boolean;
   9
  10 end utils;
  11
  12 package body utils is
  13
  14     function log2(i : natural) return integer is
  15         variable tmp : integer := i;
  16         variable ret : integer := 0;
  17     begin
  18         while tmp > 1 loop
  19             ret  := ret + 1;
  20             tmp := tmp / 2;
  21         end loop;
  22         return ret;
  23     end function;
  24
  25     function ispow2(i : integer) return boolean is
  26     begin
  27         if to_integer(to_unsigned(i, 32) and to_unsigned(i - 1, 32)) = 0 then
  28             return true;
  29         else
  30             return false;
  31         end if;
  32     end function;
  33
  34 end utils;
  35