Subversion Repositories lateq

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

-- Title      : max_finder_struct_pkg package for example1

-- Project    : 

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

-- File       : max_finder_struct_pkg.vhd

-- Author     : Wojciech M. Zabolotny ( wzab01<at>gmail.com )

-- Company    :

-- License    : BSD

-- Created    : 2013-11-01

-- Last update: 2015-09-23

-- Platform   : 

-- Standard   : VHDL'93/02

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

-- Description: Package with definitions needed to create the hierarhical

--              block for finding the maximum element and hierarchical

--              adder.

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

-- Copyright (c) 2014 

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

-- Revisions  :

-- Date        Version  Author  Description

-- 2013-11-01  1.0      WZab    Created

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

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use std.textio.all;

library work;

use work.lateq_pkg.all;

use work.ex1_pkg.all;

package ex1_trees_pkg is

  -- Constants and types for the "Max Finder" part

  constant EX1_NOF_INS_IN_CMP : integer := 3;  -- number of inputs in a single comparator

  type T_EX1_CMP_INS is array (0 to EX1_NOF_INS_IN_CMP-1) of T_USER_DATA_WITH_POS;

  -- Constant for the "Adder" part

  constant EX1_NOF_INS_IN_ADD : integer := 3;  -- number of inputs in a single adder

  type T_EX1_ADD_INS is array (0 to EX1_NOF_INS_IN_ADD-1) of T_USER_DATA_MRK;

  function ex1_nof_stages (

    constant n_of_all_ins : integer;

    constant n_of_ins : integer)

    return integer;

end package ex1_trees_pkg;

package body ex1_trees_pkg is

  -- The function returns number of stages needed to find the

  -- maximum element in a tree of comparators or adders

  function ex1_nof_stages (

    constant n_of_all_ins : integer;

    constant n_of_ins : integer)

    return integer is

    variable res : integer := 0;

    variable nins : integer := 1;

  begin  -- function ex1_nof_stages

    nins := 1;

    while nins < n_of_all_ins loop

      nins := nins * n_of_ins;

      res := res + 1;

    end loop;

    return res;

  end function ex1_nof_stages;

end package body ex1_trees_pkg;