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 log2ceil(i : natural) return integer;
   9     function ispow2(i : integer) return boolean;
  10     function round_up(i : integer; s : integer) return integer;
  11 end utils;
  12
  13 package body utils is
  14
  15     function log2(i : natural) return integer is
  16         variable tmp : integer := i;
  17         variable ret : integer := 0;
  18     begin
  19         while tmp > 1 loop
  20             ret  := ret + 1;
  21             tmp := tmp / 2;
  22         end loop;
  23         return ret;
  24     end function;
  25
  26     function log2ceil(i : natural) return integer is
  27         variable tmp : integer := i;
  28         variable ret : integer := 0;
  29     begin
  30         while tmp >= 1 loop
  31             ret  := ret + 1;
  32             tmp := tmp / 2;
  33         end loop;
  34         return ret;
  35     end function;
  36
  37     function ispow2(i : integer) return boolean is
  38     begin
  39         if to_integer(to_unsigned(i, 32) and to_unsigned(i - 1, 32)) = 0 then
  40             return true;
  41         else
  42             return false;
  43         end if;
  44     end function;
  45
  46     function round_up(i : integer; s : integer) return integer is
  47     begin
  48         return ((i + (s - 1)) / s) * s;
  49     end function;
  50 end utils;
  51