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--******************************************************************************
--*                                                                            *
--*                   5 Binary Counter with Count Enable                       *
--*                                                     Device : XC9536-PC44   *
--*                                                     Author : Seiichi Inoue *
--******************************************************************************

library ieee;                                    -- Defines std_logic types
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;


entity Counter5 is
  port ( CLK,CLEAR,CE : in std_logic;            -- Defines ports
         Q5 : out std_logic_vector(2 downto 0));
  attribute pin_assign : string;                 -- Pin Assign
  attribute pin_assign of CE : signal is "1";
  attribute pin_assign of Q5 : signal is "13,12,11";
  attribute bufg: string;
  attribute bufg of CLK : signal is "CLK";
  attribute bufg of CLEAR : signal is "SR";
end Counter5;

architecture Counter5_ARCH of Counter5 is
signal Q5_IN : std_logic_vector(2 downto 0);     -- Defines internal signals
begin
  Q5 <= Q5_IN;                                   -- Set output
  process( CLEAR, CLK, CE ) begin
    if CLEAR='0' then                            -- Clear counter ?
      Q5_IN <= "000";                            -- Yes. Clear counter
    elsif CLK='1' and CLK'event then             -- Clock rising edge ?
       if CE='1' then                            -- Yes. Count Enable ?
          if Q5_IN=4 then                        -- Yes. Count = 4 ?
             Q5_IN <= "000";                     -- Yes. Clear counter
          else                                   -- No
             Q5_IN <= Q5_IN + '1';               -- Count-up
          end if;
       end if;                                   -- Count Disable(Stop)
    end if;
  end process;
end Counter5_ARCH;

--******************************************************************************
--*                          end of 5 Binary Counter                           *
--******************************************************************************