counter6.vhd

这个是数字电子时钟

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
      use IEEE.STD_LOGIC_UNSIGNED.ALL;
      entity counter6 is
      Port ( clk : in std_logic;
      reset : in std_logic;
      din : in std_logic_vector(2 downto 0);
      dout : out std_logic_vector(2 downto 0);
      c:out std_logic);
      end counter6;
      architecture Behavioral of counter6 is
      signal count : std_logic_vector(2 downto 0);
      begin
      dout <= count;
      process(clk,reset,din)
      begin
      if reset= '0' then
      count <= din;
      c<='0';
      elsif rising_edge(clk) then
      if count="101" then
      count<="000";
      c<='1';
      else
      count<=count+1;
      c<='0';
      end if;
      end if; 
      end process;
      end Behavioral;