Subversion Repositories lateq

-------------------------------------------------------------------------------
-- Title      : Data selector
-- Project    : 
-------------------------------------------------------------------------------
-- File       : max_finder.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: This block selects from all available channels those
--              which are surrounding channel number "sel"
-------------------------------------------------------------------------------
-- 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;
library work;
use work.lateq_pkg.all;
use work.ex1_pkg.all;
 
entity data_sel is
  generic (
    N_SIDE_CHANS : integer);
  port (
    dins  : in  T_USER_DATA_SET(0 to C_N_CHANNELS-1);
    dout  : out T_USER_DATA_SET(0 to 2*N_SIDE_CHANS);
    sel   : in  T_USER_DATA_MRK;
    clk   : in  std_logic;
    rst_p : in  std_logic
    );
end data_sel;
 
architecture beh of data_sel is
 
begin
 
  ds1 : process (clk) is
    variable j : integer;
  begin  -- process ds1
    if clk'event and clk = '1' then     -- rising clock edge
      if rst_p = '1' then               -- synchronous reset (active high)
        dout <= (others => C_USER_DATA_MRK_INIT);
      else
        -- We select data surrounding the maximum.
        -- There is a problem if the maximum occures on edges of the detector.
        -- However in this example we simply add empty data
        for i in -N_SIDE_CHANS to N_SIDE_CHANS loop
          j := to_integer(sel.data) + i;
          if j < 0 then
            dout(i+N_SIDE_CHANS) <= C_USER_DATA_MRK_INIT;
          elsif j > C_N_CHANNELS-1 then
            dout(i+N_SIDE_CHANS) <= C_USER_DATA_MRK_INIT;
          else
            dout(i+N_SIDE_CHANS) <= dins(j);
          end if;
        end loop;
      end if;
    end if;
  end process ds1;
 
end beh;