Subversion Repositories versatile_fft

-------------------------------------------------------------------------------

-- Title      : vhdl_support

-- Project    : 

-------------------------------------------------------------------------------

-- File       : fft_support.vhd

-- Author     : Wojciech Zabolotny

-- Company    : 

-- License    : BSD

-- Created    : 2014-01-20

-- Last update: 2014-05-02

-- Platform   : 

-- Standard   : VHDL'87

-------------------------------------------------------------------------------

-- Description: 

-------------------------------------------------------------------------------

-- Copyright (c) 2014 

-------------------------------------------------------------------------------

-- Revisions  :

-- Date        Version  Author  Description

-- 2014-01-20  1.0      wzab    Created

-------------------------------------------------------------------------------

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use ieee.math_real.all;

use ieee.math_complex.all;

library work;

use work.icpx.all;

package fft_support_pkg is

  -- In the synthesizable version, we should replace functions

  -- with precalculated tables (probably)

  function rev(a : in unsigned)

    return unsigned;

  function rev(a : in std_logic_vector)

    return std_logic_vector;

end fft_support_pkg;

package body fft_support_pkg is

   function rev(a : in std_logic_vector)

    return std_logic_vector is

    variable result : std_logic_vector(a'range);

    alias aa        : std_logic_vector(a'reverse_range) is a;

  begin

    for i in aa'range loop

      result(i) := aa(i);

    end loop;

    return result;

  end;  -- function reverse_any_bus

   function rev(a : in unsigned)

    return unsigned is

    variable result : unsigned(a'range);

    alias aa        : unsigned(a'reverse_range) is a;

  begin

    for i in aa'range loop

      result(i) := aa(i);

    end loop;

    return result;

  end;  -- function reverse_any_bus

end package body fft_support_pkg;