display_6_led.vhd

串口通信实验程序

--display_6_led.vhd
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity display_6_led is
  port(din0: in std_logic_vector(3 downto 0);
       din1: in std_logic_vector(3 downto 0);
       din2: in std_logic_vector(3 downto 0);
       din3: in std_logic_vector(3 downto 0);
       din4: in std_logic_vector(3 downto 0);
       din5: in std_logic_vector(3 downto 0);
       clk: in std_logic;
       led_sa: out std_logic;
       led_sb: out std_logic;
       led_sc: out std_logic;
       led_a: out std_logic;
       led_b: out std_logic;
       led_c: out std_logic;
       led_d: out std_logic;
       led_e: out std_logic;
       led_f: out std_logic;
       led_g: out std_logic;
       led_dp: out std_logic);
end display_6_led ;
architecture behave of display_6_led  is
  signal q:std_logic_vector(5 downto 0);
  signal seg:std_logic_vector(6 downto 0);
  signal sel:std_logic_vector(2 downto 0);
  signal num:std_logic_vector(3 downto 0);
  signal s:std_logic_vector(2 downto 0);
begin
  s<=q(5 downto 3);
  led_sa<=sel(0);
  led_sb<=sel(1);
  led_sc<=sel(2);
  led_a<=seg(0);
  led_b<=seg(1);
  led_c<=seg(2);
  led_d<=seg(3);
  led_e<=seg(4);
  led_f<=seg(5);
  led_g<=seg(6);
  led_dp<='0';
  process(clk)
  begin
    if clk'event and clk='1' then
       if q="111111" then
          q<="000000";
       else
          q<=q+'1';
       end if;
    end if;
  end process;
  process(din0,din1,din2,din3,din4,din5,sel,clk)
  begin
  if clk'event and clk='1' then
    if s="000" then
       sel<="000";
       num<=din0;
       
    elsif s="001" then
       sel<="001";
       num<=din1;
       
    elsif s="010" then
       sel<="010";
       num<=din2;
       
    elsif s="011" then
       sel<="011";
       num<=din3;
       
    elsif s="100" then
       sel<="100";
       num<=din4;
       
    elsif s="101" then
       sel<="101";
       num<=din5;
      
    else 
       sel<="111";
       num<="XXXX";
       
    end if;
  end if;
  end process;
  seg<="0111111" when num=0 else
       "0000110" when num=1 else
       "1011011" when num=2 else
       "1001111" when num=3 else
       "1100110" when num=4 else
       "1101101" when num=5 else
       "1111101" when num=6 else
       "0000111" when num=7 else
       "1111111" when num=8 else
       "1101111" when num=9 else
       "1110111" when num=10 else
       "1111100" when num=11 else
       "0111011" when num=12 else
       "1011110" when num=13 else
       "1111001" when num=14 else
       "1110001" when num=15 else
       "0000000";
end behave;