用vhdl写FIFO 并调用FIFO IP核

下面是一个使用VHDL编写FIFO并调用FIFO IP核的示例：

首先，我们需要编写FIFO的VHDL代码。以下是一个简单的FIFO示例：

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity fifo is
    generic (
        DATA_WIDTH : integer := 8;
        DEPTH      : integer := 16
    );
    port (
        clk   : in  std_logic;
        rst   : in  std_logic;
        wr_en : in  std_logic;
        rd_en : in  std_logic;
        din   : in  std_logic_vector(DATA_WIDTH-1 downto 0);
        dout  : out std_logic_vector(DATA_WIDTH-1 downto 0);
        full  : out std_logic;
        empty : out std_logic
    );
end entity fifo;

architecture behavioral of fifo is
    type fifo_mem is array (0 to DEPTH-1) of std_logic_vector(DATA_WIDTH-1 downto 0);
    signal mem          : fifo_mem;
    signal wr_ptr      : integer range 0 to DEPTH-1 := 0;
    signal rd_ptr      : integer range 0 to DEPTH-1 := 0;
    signal count       : integer range 0 to DEPTH := 0;
begin
    process(clk, rst)
    begin
        if rst = '1' then
            mem <= (others => (others => '0'));
            wr_ptr <= 0;
            rd_ptr <= 0;
            count <= 0;
        elsif rising_edge(clk) then
            if wr_en = '1' then
                mem(wr_ptr) <= din;
                wr_ptr <= wr_ptr + 1;
                count <= count + 1;
            end if;
            if rd_en = '1' then
                dout <= mem(rd_ptr);
                rd_ptr <= rd_ptr + 1;
                count <= count - 1;
            end if;
        end if;
    end process;

    full <= '1' when count = DEPTH else '0';
    empty <= '1' when count = 0 else '0';
end architecture behavioral;

接下来，我们将FIFO IP核实例化到我们的设计中。以下是一个示例代码，展示了如何实例化FIFO IP核并连接到上面的FIFO模块：

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity top_design is
    port (
        clk   : in  std_logic;
        rst   : in  std_logic;
        wr_en : in  std_logic;
        rd_en : in  std_logic;
        din   : in  std_logic_vector(7 downto 0);
        dout  : out std_logic_vector(7 downto 0);
        full  : out std_logic;
        empty : out std_logic
    );
end entity top_design;

architecture behavioral of top_design is
    component fifo is
        generic (
            DATA_WIDTH : integer := 8;
            DEPTH      : integer := 16
        );
        port (
            clk   : in  std_logic;
            rst   : in  std_logic;
            wr_en : in  std_logic;
            rd_en : in  std_logic;
            din   : in  std_logic_vector(DATA_WIDTH-1 downto 0);
            dout  : out std_logic_vector(DATA_WIDTH-1 downto 0);
            full  : out std_logic;
            empty : out std_logic
        );
    end component fifo;

    signal fifo_din   : std_logic_vector(7 downto 0);
    signal fifo_dout  : std_logic_vector(7 downto 0);
    signal fifo_full  : std_logic;
    signal fifo_empty : std_logic;
begin
    fifo_inst : fifo
        generic map (
            DATA_WIDTH => 8,
            DEPTH => 16
        )
        port map (
            clk => clk,
            rst => rst,
            wr_en => wr_en,
            rd_en => rd_en,
            din => fifo_din,
            dout => fifo_dout,
            full => fifo_full,
            empty => fifo_empty
        );

    -- 连接FIFO IP核的输入和输出接口到其他信号或模块

    -- 例如，将FIFO IP核的输入接口连接到顶层设计的输入信号
    fifo_din <= din;

    -- 将FIFO IP核的输出接口连接到顶层设计的输出信号
    dout <= fifo_dout;

    -- 将FIFO IP核的状态信号连接到顶层设计的输出信号
    full <= fifo_full;
    empty <= fifo_empty;
end architecture behavioral;

上述示例中，我们通过实例化`fifo`模块，并将FIFO IP核的输入和输出接口与顶层设计的信号连接起来。这样，我们就可以在顶层设计中使用FIFO IP核了。

请注意，具体的实例化过程可能因为使用的工具和FPGA器件而有所不同。确保参考相关文档和用户手册来了解如何正确实例化和调用FIFO IP核。