数码显示器
数码管显示原理：
程序：
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity smg is
port(
a:in std_logic_vector(3 downto 0)
y:out std_logic_vector(6 downto 0)
);
end;
architecture bhv of smg is
begin
process(a)
begin
case a is
when "0000"=> y<="0111111";--0
when "0001"=> y<="0000110";--1
when "0010"=> y<="1011011";--2
when "0011"=> y<="1001111";--3
when "0100"=> y<="1100110";--4
when "0101"=> y<="1101101";--5
when "0110'=> y<="1111101";--6
when "0111"=> y<="0000111";--7
when "1000"=> y<="1111111";--8
when "1001"=> y<="1101111"--9
when others=> y<="0000000"--灭
end case;
end process;
end bhv;
原理图：
数码管仿真图：
