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我想使用四个按钮作为输入，三个七段 LED 显示器作为输出。两个按钮应通过 16 个 RAM 位置上下移动；另外两个应该增加和减少当前显示的内存位置的内容。我现在正在尝试使用 ModelSim 测试台模拟我的设计，并按下按钮。这是我认为是我的代码的相关部分：

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

entity DE2_TOP is

  port (
    KEY : in std_logic_vector(3 downto 0);         -- Push button
    );

end DE2_TOP;

architecture datapath of DE2_TOP is

begin  
  U1: entity work.lab1 port map (
    key => key,         
  );

end datapath;

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

entity raminfr is                     -STANDARD RAM INFERENCE
    port (
        clk : in std_logic;
        we : in std_logic;
        a : in unsigned(3 downto 0);
        di : in unsigned(7 downto 0);
        do : out unsigned(7 downto 0)
    );
end raminfr;

architecture rtl of raminfr is

type ram_type is array (0 to 15) of unsigned(7 downto 0);
signal RAM : ram_type;
signal read_a : unsigned(3 downto 0);
begin
process (clk)
begin
    if rising_edge(clk) then
        if we = '1' then
            RAM(to_integer(a)) <= di;
        end if;
        read_a <= a;
    end if;
end process;
do <= RAM(to_integer(read_a));
end rtl;

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

entity lab1 is
    port(
        clock : in std_logic;
        key : in std_logic_vector(3 downto 0); 
        );
end lab1;

architecture up_and_down of lab1 is
    signal value_in_ram : unsigned(7 downto 0);
    signal clk : std_logic;
    signal we : std_logic;
    signal value_counter    : unsigned(7 downto 0) ;
    signal register_counter : unsigned(3 downto 0);
        begin
    U1: entity work.raminfr port map (
        a   => register_counter,
        di  => value_counter,
        do  => value_in_ram,
        clk => clk,
        we  => we
    );

    process(clock)
        begin
            if rising_edge(clock) then
                if (key(3)='0' and key(2)='0' and key(1)='1' and key(0)='0') then
                    value_counter <= value_counter + "1";   
                elsif (key(3)='0' and key(2)='0' and key(1)='0' and key(0)='1') then  
                    value_counter <= value_counter - "1";   
                elsif (key(3)='1' and key(2)='0' and key(1)='0' and key(0)='0') then
                    register_counter<= register_counter + "1";
                    value_counter <= value_in_ram;
                elsif (key(3)='0' and key(2)='1' and key(1)='0' and key(0)='0') then
                    register_counter<= register_counter - "1";
                    value_counter <= value_in_ram;
                end if;
            end if;
    end process;
end architecture up_and_down;

问题是，尽管在我的测试台中初始化了“键”（按钮），ModelSim 仍然将对象列为“UUUU”。这是我的测试台的代码，它位于一个单独的文件中：

library ieee;
use ieee.std_logic_1164.all;

entity DE2_TOP_TEST is
end;

architecture BENCH of DE2_TOP_TEST is
signal KEY : std_logic_vector(3 downto 0);

begin
    KEY<="0010";
    U1: entity work.DE2_TOP port map (
        key=>key,
    );
end BENCH;

有谁知道怎么了？

4

1 回答 1

1

您在设计中使用寄存器。因此，您需要在时钟输入中添加一个信号：

constant tb_clk_period : time       := (1 sec) / 10_000_000; -- 10 MHz
signal   tb_clk        : std_ulogic := '0';
...
-- clock generator
tb_clk <= not tb_clk after tb_clk_period / 2;
于 2013-03-04T16:44:24.043 回答