counter6.vhd

VHDL实现的电子钟的基本功能

--文件名：counter6.vhd。
--功能：6进制计数器，有进位C
--最后修改日期：
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;