FF/舱口和其他警告

Question

我的VHDL代码怎么了？以下是代码：

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity main is
    port(
        -- 50 MHz clock
        cp : in std_logic;
        -- Reset signal
        reset : in std_logic;
        -- PS/2 data and clock lines
        ps2d, ps2c : in std_logic;
        -- 7-segment display segments
        segments : out std_logic_vector (7 downto 0);
        -- Anode control
        an : out std_logic_vector (3 downto 0);
        -- Data out to LEDs
        dout : out std_logic_vector (7 downto 0)
    );
end main;

architecture Behavioral of main is
    -- Data from keyboard entity (scancode)
    signal data : std_logic_vector (7 downto 0);
    -- 7 segments of display
    signal segReg, segNext : std_logic_vector (6 downto 0);
    signal tickDone : std_logic;
begin
    -- Just an entity that reads PS/2 keyboard data
    -- rx_done is tick (20 ns)
    S1: entity keyboard port map ( cp => cp, ps2d => ps2d, ps2c => ps2c,
                          rx_done => tickDone, dout => data);
    dout <= data;
    an <= "1110";
    segments(6 downto 0) <= segReg;
    -- Turn off dot
    segments(7) <= '1';
    process (cp, reset)
    begin
        if reset = '1' then
            segReg <= (others => '0');
        elsif rising_edge (cp) then
            segReg <= segNext;
        end if;
    end process;

    process (tickDone, segReg)
    begin
        segNext <= segReg;
        if tickDone = '1' then
            if data = x"16" then
                -- Number 1
                segNext <= "1001111";
            elsif data = x"1E" then
                -- Number 2
                segNext <= "0010010";
            elsif data = x"26" then
                -- Number 3
                segNext <= "0000110";
            elsif data = x"25" then
                -- Number 4
                segNext <= "1001100";
            else
                segNext <= "1111111";
            end if;
        end if;
    end process;

end Behavioral;

当我试图合成它/生成编程文件时，我会收到以下警告：

WARNING:Xst:819 - "C:/VHDL_projekti/PS2K/main.vhd" line 48: The following signals are missing in the process sensitivity list:
WARNING:Xst:2734 - Property "use_dsp48" is not applicable for this technology.
WARNING:Xst:1710 - FF/Latch  <segReg_0> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_1> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_2> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_3> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_4> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_5> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1710 - FF/Latch  <segReg_0> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_1> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_2> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_3> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_4> (without init value) has a constant value of 0 in block <main>.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch  <segReg_5> (without init value) has a constant value of 0 in block <main>.
WARNING:Par:288 - The signal reset_IBUF has no load.  PAR will not attempt to route this signal.
WARNING:Par:283 - There are 1 loadless signals in this design. This design will cause Bitgen to issue DRC warnings.
WARNING:PhysDesignRules:367 - The signal <reset_IBUF> is incomplete. The signal

我一直在看代码，我没有发现任何问题，但显然我做错了什么。

1. “进程敏感性列表中缺少以下信号”，这可能是西林克斯的ISE错误吗？我不明白为什么在第48行的进程敏感列表中我需要任何其他信号.
2. 由于其他FF/舱口修整，块中的常数为0“好吧，我做错了什么？”我根本不想用闩锁.
3. “信号reset_IBUF没有负载。PAR不会尝试路由此信号。”这是什么意思？我的复位信号怎么了？为什么它不完整？

这段代码是我尝试使用带有PS/2启动板的斯巴达-3键盘。实体“键盘”进行读取，它正在正常工作(当我单独测试它时，我在dout信号上得到正确的扫描代码(我在LED上看到它)。rx_done是表示扫描代码已被成功读取的信号的勾选(20 Ns)。

因此，我只想看看我是否能以某种方式识别扫描代码(在我的第二个过程中，我比较数据信号并将正确的值与segNext信号进行比较)，并在七段显示上显示一些东西。当我让它开始工作时，我将实现正确的行为(检测所有的扫描代码、额外的键、按键和按键事件)。

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity main is
    port(
        -- 50 MHz clock
        cp : in std_logic;
        -- Reset signal
        reset : in std_logic;
        -- PS/2 data and clock lines
        ps2d, ps2c : in std_logic;
        -- 7-segment display segments
        segments : out std_logic_vector (7 downto 0);
        -- Anode control
        an : out std_logic_vector (3 downto 0);
        -- Data out to LEDs
        dout : out std_logic_vector (7 downto 0)
    );
end main;

architecture Behavioral of main is
    -- Data from keyboard entity (scancode)
    signal data : std_logic_vector (7 downto 0);
    -- 7 segments of display
    signal segReg, segNext : std_logic_vector (6 downto 0);
    signal tickDone : std_logic;
begin
    -- Just entity that reads PS/2 keyboard data
    -- rx_done is tick (20 ns)
    S1: entity keyboard port map ( cp => cp, ps2d => ps2d, ps2c => ps2c,
                          rx_done => tickDone, dout => data);
    dout <= data;
    an <= "1110";
    segments(6 downto 0) <= segReg;
    -- Turn off dot
    segments(7) <= '1';
    process (cp, reset)
    begin
        if reset = '1' then
            segReg <= (others => '0');
        elsif rising_edge (cp) then
            segReg <= segNext;
        end if;
    end process;

    process (tickDone, segReg, data)
    begin
        if tickDone = '1' then
            if data = x"16" then
                -- Number 1
                segNext <= "1001111";
            elsif data = x"1E" then
                -- Number 2
                segNext <= "0010010";
            elsif data = x"26" then
                -- Number 3
                segNext <= "0000110";
            elsif data = x"25" then
                -- Number 4
                segNext <= "1001100";
            else
                segNext <= "1111111";
            end if;
        else
            segNext <= segReg;
        end if;
    end process;

end Behavioral;

不幸的是，在这些编辑之后，我仍然有这样的警告：

WARNING:Xst:1710 - FF/Latch <segReg_0> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_1> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_2> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_3> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_4> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_5> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_6> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1710 - FF/Latch <segReg_0> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_1> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_2> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_3> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_4> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1895 - Due to other FF/Latch trimming, FF/Latch <segReg_5> (without init value) has a constant value of 0 in block <main>. This FF/Latch will be trimmed during the optimization process.
WARNING:Par:288 - The signal reset_IBUF has no load.  PAR will not attempt to route this signal.
WARNING:Par:283 - There are 1 loadless signals in this design. This design will cause Bitgen to issue DRC warnings.

Answer 1

2)“由于其他FF/舱口修整，块中的恒定值为0”好的，我做错了什么？我根本不想用闩锁.

这告诉您，这些存储元素是由常量驱动的，而不是锁存。你模拟过这个吗？

Answer 2

在组合过程中，您正在阅读tickDone、segReg和data。后者在您的灵敏度列表中丢失，这将导致锁存。

另外，不要使用STD_LOGIC_ARITH或STD_LOGIC_UNSIGNED。它们不规范，有几个问题。http://parallelpoints.com/node/3

Answer 3

您的第二个进程似乎试图使用tickDone作为时钟信号，但是您没有正确地使用它(例如: if rising_edge(tickDone)或类似的)，因此您正在创建锁存器而不是触发器(如果tickDone='1')。使用锁存器时，虽然tickDone很高，但输出取决于数据信号的状态，而数据信号不在敏感列表中。最后，在敏感列表中使用segReg，按照编写代码的方式，您将segReg异步分配给segNext。

您是否忘记了使用cp信号作为时钟将第二个进程中的所有内容封装在if语句中？你写的这样会更有意义.