xhour.vhd

来自「DEMO2 数码管扫描显示电路/DEMO4 计数时钟 DEMO5 键盘扫描设计」· VHDL 代码 · 共 44 行

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

entity xhour is
    port (
        clkhour: in STD_LOGIC;
        reset: in STD_LOGIC;
        hourout: out STD_LOGIC_VECTOR (5 downto 0)
    );
end xhour;

architecture xhour_arch of xhour is
signal hour : std_logic_vector(5 downto 0);
begin
  -- <<enter your statements here>>

  process(reset,clkhour,hour)
  alias lcount : std_logic_vector(3 downto 0) is hour(3 downto 0);
  alias hcount : std_logic_vector(1 downto 0) is hour(5 downto 4);
  begin
  if reset='0' then
    hourout<="000000";
    hour<="000000";
  else
    if (clkhour='1' and clkhour'event) then           
      if lcount=9 then
         lcount<="0000";
         hcount<=hcount+1;
      else
        if hour="100011" then
         hour<="000000";
        else
         lcount<=lcount+1;
        end if;
      end if;
    end if;
    hourout<=hour;
  end if;
  end process;   
  
end xhour_arch;