zhankong.vhd

本频率计具有测周、测频、测量占空比等基本功能

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity zhankong is
port
(clk,clkin:in std_logic;
 beichu1,beichu2,beichu3,chu1,chu2,chu3:out Integer range 0 to 9
);
end;

architecture a of zhankong is
signal En,High,m,n,Entransfer:std_logic;
signal Highnum1,Highnum2,Highnum3,Totalnum1,Totalnum2,Totalnum3: Integer range 0 to 9;
begin
  process(clkin)
    begin
    if rising_edge(clkin) then
       En<=not En;             --En?clkin????
      m<=not m;              --High='1'??????????
    end if;
      end process;
  process(clkin)
    begin
    if falling_edge(clkin) then
       n<=not n;              --High='0'?????????? 
    end if;
   end process;
  High<=m xor n;
  process(clk)
    begin
     if rising_edge(clk) then
       if En='1' then          --En='1'?????
         if Entransfer='1' then   --Entransfer='1'????????
            Entransfer<='0';
            beichu1<=Highnum1;
            beichu2<=Highnum2;
            beichu3<=Highnum3;
            chu1<=Totalnum1;
            chu2<=Totalnum2;
            chu3<=Totalnum3;
            Highnum1<=0; 
              Highnum2<=0;  
            Highnum3<=0;       --??????????????
            Totalnum1<=0;
            Totalnum2<=0;
            Totalnum3<=0;
           
          end if;
        else Entransfer<='1';  --En='0'?????
               if Totalnum1=9 then
           if Totalnum2=9 then
            if Totalnum3=9 then
            null;
            else 
             
             Totalnum3<=Totalnum3+1;
             Totalnum2<=0;
             Totalnum1<=0;
            end if;
           else
           
             Totalnum2<=Totalnum2+1;
             Totalnum1<=0;
           end if;
          else
             
             Totalnum1<=Totalnum1+1;
             --Totalnum<=Totalnum+1;
           end if;
             if High='1' then
              if Highnum1=9 then
           if Highnum2=9 then
            if Highnum3=9 then
            null;
            else 
             
             Highnum3<=Highnum3+1;
             Highnum2<=0;
             Highnum1<=0;
            end if;
           else
           
             Highnum2<=Highnum2+1;
             Highnum1<=0;
           end if;
          else
             
             Highnum1<=Highnum1+1;
             --Totalnum<=Totalnum+1;
           end if;

              -- Highnum<=Highnum+1;
             end if;
        end if;
       end if;
      end process;
  end a;