led_disp.vhd

首先将下载板插到主板上面. 1。源文件保存在src目录

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

entity led_disp is
port(
      pressed : in std_logic;
      value   : in std_logic_vector(3 downto 0);
      disp    : out std_logic_vector(6 downto 0)
    );
end led_disp;

architecture rtl of led_disp is
begin 
 process(value)
  begin
  if(pressed='1')then
   case value is
    when "0000" => disp <="0111111";
    when "0001" => disp <="0000110";
    when "0010" => disp <="1011011";
    when "0011" => disp <="1001111";
    when "0100" => disp <="1100110";
    when "0101" => disp <="1101101";
    when "0110" => disp <="1111101";
    when "0111" => disp <="0000111";
    when "1000" => disp <="1111111";
    when "1001" => disp <="1101111";
    when "1010" => disp <="1110111";
    when "1011" => disp <="1111100";
    when "1100" => disp <="0111001";
    when "1101" => disp <="1011110";
    when "1110" => disp <="1111001";
    when "1111" => disp <="1110001";
    when others => disp <="0000000";
   end case;
 end if;
end process;

end rtl;