使用Quartus II+VHDL的if语句七段数码管译码器电路

好的，针对您的问题，我可以给出以下的VHDL代码实现七段数码管译码器电路：

library ieee;
use ieee.std_logic_1164.all;

entity seven_segment_decoder is
    port (
        input_num : in std_logic_vector(3 downto 0);
        output_seg : out std_logic_vector(6 downto 0)
    );
end entity;

architecture behavioral of seven_segment_decoder is
begin
    process(input_num)
    begin
        case input_num is
            when "0000" => output_seg <= "0000001"; -- 0
            when "0001" => output_seg <= "1001111"; -- 1
            when "0010" => output_seg <= "0010010"; -- 2
            when "0011" => output_seg <= "0000110"; -- 3
            when "0100" => output_seg <= "1001100"; -- 4
            when "0101" => output_seg <= "0100100"; -- 5
            when "0110" => output_seg <= "0100000"; -- 6
            when "0111" => output_seg <= "0001111"; -- 7
            when "1000" => output_seg <= "0000000"; -- 8
            when "1001" => output_seg <= "0000100"; -- 9
            when others => output_seg <= "1111111"; -- error
        end case;
    end process;
end architecture;

这个代码实现了一个四位二进制输入到七段数码管输出的译码器电路。其中，输入信号 `input_num` 是一个四位的二进制数，输出信号 `output_seg` 是一个七位的七段数码管输出信号。在代码中，使用了 `case` 语句来实现不同输入值对应的七段数码管输出值。