过程中的inout参数问题

Question

我正在为测试平台编写总线功能模型，我正在使用一个过程来处理读写操作，理想情况下我想使用一个声明为inout的总线。

我正在使用记录类型来实例化我的总线，但是当我在我的过程调用中将其声明为inout参数时，它似乎适用于来自过程的输出信号，但不识别过程中的输入。任何信号输入都是未初始化的＆＃34; U＆＃34;。我知道合成这个方法不起作用，但对于测试平台我认为可以将总线实例化为inout。

我的记录类型和过程实例化如下：

type t_apbp_intf is record
    -- APB-pipe Interface
    paddr   : std_logic_vector(31 downto 0);
    psel    : std_logic;
    penable : std_logic;
    pwrite  : std_logic;
    pwdata  : std_logic_vector(31 downto 0);
    pstrb   : std_logic_vector(3 downto 0);
    prdata  : std_logic_vector(31 downto 0);
    pready  : std_logic;
    pslverr : std_logic;
    prdvld  : std_logic;
end record t_apbp_intf;

procedure nai_bus_cyc(
    wr_rd_n          : in    std_logic;
    addr_in          : in    std_logic_vector(31 downto 0); -- Address
    data_in          : in    std_logic_vector(31 downto 0); -- Data to be written
    signal tb_m_apbp : inout t_apbp_intf) is
begin
    if wr_rd_n = C_BUS_WR then
        wait until rising_edge(tb_clk);
        tb_m_apbp.paddr   <= addr_in;
        tb_m_apbp.psel    <= '1';
        tb_m_apbp.penable <= '1';
        tb_m_apbp.pwrite  <= '1';
        tb_m_apbp.pwdata  <= data_in;
        tb_m_apbp.pstrb   <= "1111";
        wait until rising_edge(tb_clk) and (tb_m_apbp.pready = '1');
        tb_m_apbp.paddr   <= (others => '0');
        tb_m_apbp.psel    <= '0';
        tb_m_apbp.penable <= '0';
        tb_m_apbp.pwrite  <= '0';
        tb_m_apbp.pwdata  <= (others => '0');
        tb_m_apbp.pstrb   <= "0000";
    else
        wait until rising_edge(tb_clk);
        tb_m_apbp.paddr   <= addr_in;
        tb_m_apbp.psel    <= '1';
        tb_m_apbp.penable <= '1';
        tb_m_apbp.pwrite  <= '0';
        tb_m_apbp.pwdata  <= (others => '0');
        tb_m_apbp.pstrb   <= "0000";
        wait until rising_edge(tb_clk) and (tb_sprvalid_bus = '1');
        tb_m_apbp.paddr   <= (others => '0');
        tb_m_apbp.psel    <= '0';
        tb_m_apbp.penable <= '0';
        tb_m_apbp.pwrite  <= '0';
        tb_m_apbp.pwdata  <= (others => '0');
        tb_m_apbp.pstrb   <= "0000";
    end if;
end procedure;