library IEEE;use IEEE.std_logic_1164.all;use IEEE.numeric_STD.all;entity ref_cntr isport (	auto_ref: out std_logic;	p_auto_ref: out std_logic;	Reset: in std_logic;	Clk: in std_logic;	clr_ref: in std_logic;	ref_max: in unsigned(15 downto 0));end entity ref_cntr;architecture ref_cntr_arch of ref_cntr is signal rcount: unsigned(15 downto 0);signal count_N: unsigned(15 downto 0);beginprocess (Clk, Reset, ref_max, count_N, rcount, clr_ref)begin  if (Reset = '0') then    rcount <= ref_max;    auto_ref <= '0';  elsif rising_edge(Clk) then    rcount <= count_N;    if (rcount = X"0000") then      auto_ref <= '1';      if (clr_ref = '1') then        auto_ref <= '1';        p_auto_ref <= '0';        if (rcount = X"0003") then          p_auto_ref <= '1';        end if;      end if;    end if;  end if;end process;process (rcount, ref_max)begin  if (rcount = X"0000") then    count_N <= ref_max;  else    count_N <= rcount - 1;  end if;end process;end architecture ref_cntr_arch;