ipk.vhd

使用vhdl编写的一段程序。 主要功能是声音周期计算

  library ieee;
  use ieee.std_logic_1164.all;
  use ieee.std_logic_signed.all;
  use ieee.std_logic_arith.all;
  use work.pack.all;  
  
  entity ipk_comparator is
    port (
      clk, en_ipk, en_clr      : in std_logic;
      result                   : in std_logic_vector(7 downto 0);
      pp                       : out std_logic_vector(7 downto 0)
      );
  end ipk_comparator;
  
  architecture behavioral of ipk_comparator is   
  
    type state_type is (state0, state1,state2);
    type reg_type is record
                        state  : state_type;
                        count  : std_logic_vector(5 downto 0);
                        ipos   : std_logic_vector(5 downto 0);
                        peak   : std_logic_vector(7 downto 0);
                        ipk    : std_logic_vector(9 downto 0);
                        threshold_1 : std_logic_vector(15 downto 0);
                        threshold   : std_logic_vector(7 downto 0);
    end record;   
    signal r,rin: reg_type;
  
  begin  

    process (en_ipk, r, result, en_clr)
        variable v : reg_type;
      begin
          
          v := r;
          
          case r.state is
              when state0 =>
                  if en_clr = '0' then
                    v.state := state1;
                  end if;
                  
              when state1 =>
                  if en_clr = '0' then
                    v.state := state2;
                  end if;
                  v.count := "000000";
                  v.peak  := (others => '0');
                  v.ipos  := (others => '0');
                  v.ipk   := (others => '0');
                  v.threshold_1:= result * "01001110";
                  v.threshold  := v.threshold_1(15 downto 8);
                 
              when state2 =>
                  if en_clr = '0' then
                    if r.count = "000000" then
                        v.count := r.count + 1;
                        v.peak  := result;
                        v.ipos  := "000101";
                    elsif r.count = "011001" then
                     
                     if r.peak < result then
                         v.peak := result;
                         v.ipos := "011110";
                     end if;
                     
                     if v.peak > v.threshold then
                         v.ipk := v.ipos * "0100";
                     else
                         v.ipk := (others => '0');
                     end if;
                 
                    else
                        v.count := r.count + 1;
                     if v.peak < result then
                         v.peak := result;
                         v.ipos := r.count + 5;
                     end if;
                    end if; 
                   end if;
             end case;
                      
      if en_ipk = '0' then
          v.state := state0;
          v.count := "000000";
          v.peak  := (others => '0');
          v.ipos  := (others => '0');
          v.ipk   := (others => '0');
          v.threshold_1 := (others => '0');
          v.threshold   := (others => '0');
      end if;
      
        rin <= v; 
        pp  <= v.ipk(7 downto 0);
                 
     end process;

    process (rin, clk)
    begin  
      if clk'event and clk = '1' then
        
        r <= rin;

      end if;
    end process;
end behavioral;