用VHDL语言实现一个二输入与非门，并写出其测试激励

以下是用VHDL语言实现一个二输入与非门的代码：

entity and_not is
    port (a, b : in std_logic;
          y : out std_logic);
end and_not;

architecture and_not_arch of and_not is
begin
    y <= not (a and b);
end and_not_arch;

以下是该模块的测试激励代码：

library ieee;
use ieee.std_logic_1164.all;

entity and_not_tb is
end and_not_tb;

architecture testbench of and_not_tb is
    signal a, b, y : std_logic;
begin
    uut : entity work.and_not
        port map(a => a, b => b, y => y);

    stimulus : process
    begin
        a <= '0'; b <= '0'; wait for 10 ns;
        assert (y = '1') report "Test failed for input A='0', B='0'" severity error;

        a <= '0'; b <= '1'; wait for 10 ns;
        assert (y = '1') report "Test failed for input A='0', B='1'" severity error;

        a <= '1'; b <= '0'; wait for 10 ns;
        assert (y = '1') report "Test failed for input A='1', B='0'" severity error;

        a <= '1'; b <= '1'; wait for 10 ns;
        assert (y = '0') report "Test failed for input A='1', B='1'" severity error;

        wait;
    end process stimulus;
end testbench;

在测试激励中，通过对输入的不同组合进行测试，检查输出是否符合预期。如果不符合预期，则会输出一个错误报告。