VHDL警告Xst：1293 FF /锁存器的常数值为0
[英]VHDL Warning Xst:1293 FF/Latch has a constant value of 0
问题描述
当我是VHDL的初学者时，互联网上的答案都对我没有帮助。
我正在vhdl中使用按钮和LED制作密码界面。 我的程序可以按预期正确模拟。
基本上，我希望输入错误密码时LED闪烁，但输入正确密码时LED持续发光。 您可以看到，这在模拟中有效。
模拟图像 （在模拟中，首先输入错误的密码，然后输入正确的密码）
进行合成时，会出现以下主要警告：
Optimizing unit <safehouse> ...
WARNING:Xst:1293 - FF/Latch <entry_pass.ncount_6> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_7> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
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.
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VHDL代码是：
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
entity safehouse is
Port ( keyled : out STD_LOGIC_VECTOR(0 TO 4);
keypad : in STD_LOGIC_VECTOR(0 to 7);
clk : in STD_LOGIC );
end safehouse;
architecture safehouse of safehouse is
signal temp : std_logic_vector(0 to 7) := "00000000";
begin
entry_pass: process(clk,keypad,temp)
type integer_vector is array (0 to 3) of integer;
variable i : integer := 0;
constant passoriginal : integer_vector := (2,5,2,6);
variable passcode : integer_vector := (0,0,0,0);
variable dcount : integer := 0;
variable ncount : integer := 0;
begin
if (rising_edge(clk)) then
keyled(4) <= '1';
if i < 4 then
keyled(0) <= '1';
if (temp /= keypad) then
case keypad is
when "10001000" =>
passcode(i) := 1;
keyled(i+1) <= '1';
i := i + 1;
when "10000100" =>
passcode(i) := 2;
keyled(i+1) <= '1';
i := i + 1;
when "10000010" =>
passcode(i) := 3;
keyled(i+1) <= '1';
i := i + 1;
when "10000001" =>
passcode(i) := 10;
keyled(i+1) <= '1';
i := i + 1;
when "01001000" =>
passcode(i) := 4;
keyled(i+1) <= '1';
i := i + 1;
when "01000100" =>
passcode(i) := 5;
keyled(i+1) <= '1';
i := i + 1;
when "01000010" =>
passcode(i) := 6;
keyled(i+1) <= '1';
i := i + 1;
when "01000001" =>
passcode(i) := 11;
keyled(i+1) <= '1';
i := i + 1;
when "00101000" =>
passcode(i) := 7;
keyled(i+1) <= '1';
i := i + 1;
when "00100100" =>
passcode(i) := 8;
keyled(i+1) <= '1';
i := i + 1;
when "00100010" =>
passcode(i) := 9;
keyled(i+1) <= '1';
i := i + 1;
when "00100001" =>
passcode(i) := 12;
keyled(i+1) <= '1';
i := i + 1;
when "00011000" =>
passcode(i) := 14;
keyled(i+1) <= '1';
i := i + 1;
when "00010100" =>
passcode(i) := 0;
keyled(i+1) <= '1';
i := i + 1;
when "00010010" =>
passcode(i) := 15;
keyled(i+1) <= '1';
i := i + 1;
when "00010001" =>
passcode(i) := 13;
keyled(i+1) <= '1';
i := i + 1;
when others =>
keyled(4) <= '1';
end case;
temp <= keypad;
end if;
else
if passcode = passoriginal then
dcount := dcount + 1;
if dcount >= 50000000 then
keyled <= ('1','1','1','1','1');
dcount := 1;
ncount := ncount + 1;
if ncount >= 8 then
i := 0;
passcode := (0,0,0,0);
keyled <= ('0','0','0','0','1');
ncount := 1;
end if;
end if;
else
dcount := dcount + 1;
if dcount >= 50000000 then
if (ncount rem 2) = 0 then
keyled <= ('1','1','1','1','1');
else
keyled <= ('0','0','0','0','1');
end if;
dcount := 1;
ncount := ncount + 1;
if ncount >= 8 then
i := 0;
keyled <= ('1','0','0','0','1');
ncount := 1;
end if;
end if;
end if;
end if;
end if;
end process;
end safehouse;
我知道变量ncount已被修整，但我需要它。 变量ncount用于创建4秒的延迟，而变量dcount用于创建0.5秒的延迟。 没有变量ncount，我将无法创建4秒钟的延迟。
完整的警告是：
WARNING:Xst:1710 - FF/Latch <keyled_4> (without init value) has a constant value of 1 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
Optimizing unit <safehouse> ...
WARNING:Xst:1293 - FF/Latch <entry_pass.ncount_6> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_7> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_8> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_11> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_9> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_10> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_14> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_12> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_13> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_17> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_15> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_16> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_20> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_18> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_19> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_23> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_21> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_22> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_26> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_24> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_25> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_29> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_27> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_28> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_30> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_31> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.dcount_26> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.dcount_29> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.dcount_27> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.dcount_28> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.dcount_30> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.dcount_31> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_3> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_4> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_5> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_6> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_7> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_8> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_9> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_10> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_11> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_12> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_13> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_14> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_15> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_16> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_17> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_18> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_19> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_20> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_21> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_22> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_23> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_24> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_25> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_26> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_27> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_28> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_29> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_30> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.i_31> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_4> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_3> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
WARNING:Xst:1896 - Due to other FF/Latch trimming, FF/Latch <entry_pass.ncount_5> has a constant value of 0 in block <safehouse>. This FF/Latch will be trimmed during the optimization process.
我正在使用的FPGA开发板是：Xilinx Spartan 6 XC6SLX9 TQG144。 请帮我。
1 个解决方案
解决方案1
0 已采纳 2017-08-11 16:49:57
我自己解决了这个问题。 谢谢大家。
用信号替换变量并添加约束（它们的值范围）
向变量添加约束可以解决该问题。
将变量（如i，dcount，ncount等）更改为信号后，程序能够在没有任何警告的情况下进行合成，这一事实使我认为问题出在If语句的 范围内。 由于对变量的赋值操作位于嵌套的if语句内部，因此合成器未在所需范围内找到变量值的变化，并假定其具有恒定值。 信号的范围比变量好得多。
但是，由于我是初学者，我上面提到的原因可能是错误的。 但是这里是解决我的问题的代码。
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
entity safehouse is
Port ( keyled : out STD_LOGIC_VECTOR(0 TO 4);
keypad : in STD_LOGIC_VECTOR(0 to 7);
clk : in STD_LOGIC );
end safehouse;
architecture safehouse of safehouse is
signal temp : std_logic_vector(0 to 7) := "00000000";
signal dcount : integer range 0 to 100000000 := 0;
signal ncount : integer range 0 to 10 := 0;
signal i : integer range 0 to 5;
begin
entry_pass: process(clk,keypad,temp,dcount,ncount,i)
type integer_vector is array (0 to 3) of integer;
constant passoriginal : integer_vector := (2,5,2,6);
variable passcode : integer_vector := (0,0,0,0);
begin
if (rising_edge(clk)) then
keyled(4) <= '1';
if i < 4 then
keyled(0) <= '1';
if (temp /= keypad) then
case keypad is
when "10001000" =>
passcode(i) := 1;
keyled(i+1) <= '1';
i <= i + 1;
when "10000100" =>
passcode(i) := 2;
keyled(i+1) <= '1';
i <= i + 1;
when "10000010" =>
passcode(i) := 3;
keyled(i+1) <= '1';
i <= i + 1;
when "10000001" =>
passcode(i) := 10;
keyled(i+1) <= '1';
i <= i + 1;
when "01001000" =>
passcode(i) := 4;
keyled(i+1) <= '1';
i <= i + 1;
when "01000100" =>
passcode(i) := 5;
keyled(i+1) <= '1';
i <= i + 1;
when "01000010" =>
passcode(i) := 6;
keyled(i+1) <= '1';
i <= i + 1;
when "01000001" =>
passcode(i) := 11;
keyled(i+1) <= '1';
i <= i + 1;
when "00101000" =>
passcode(i) := 7;
keyled(i+1) <= '1';
i <= i + 1;
when "00100100" =>
passcode(i) := 8;
keyled(i+1) <= '1';
i <= i + 1;
when "00100010" =>
passcode(i) := 9;
keyled(i+1) <= '1';
i <= i + 1;
when "00100001" =>
passcode(i) := 12;
keyled(i+1) <= '1';
i <= i + 1;
when "00011000" =>
passcode(i) := 14;
keyled(i+1) <= '1';
i <= i + 1;
when "00010100" =>
passcode(i) := 0;
keyled(i+1) <= '1';
i <= i + 1;
when "00010010" =>
passcode(i) := 15;
keyled(i+1) <= '1';
i <= i + 1;
when "00010001" =>
passcode(i) := 13;
keyled(i+1) <= '1';
i <= i + 1;
when others =>
keyled(4) <= '1';
end case;
temp <= keypad;
end if;
else
if passcode = passoriginal then
dcount <= dcount + 1;
if dcount >= 50000000 then
keyled <= ('1','1','1','1','1');
dcount <= 1;
ncount <= ncount + 1;
if ncount >= 8 then
i <= 0;
passcode := (0,0,0,0);
keyled <= ('0','0','0','0','1');
ncount <= 1;
end if;
end if;
else
dcount <= dcount + 1;
if dcount >= 50000000 then
if (ncount rem 2) = 0 then
keyled <= ('1','1','1','1','1');
else
keyled <= ('0','0','0','0','1');
end if;
dcount <= 1;
ncount <= ncount + 1;
if ncount >= 8 then
i <= 0;
keyled <= ('1','0','0','0','1');
ncount <= 1;
end if;
end if;
end if;
end if;
end if;
end process;
end safehouse;
这是我在这个网站上的第一个问题。 我将对每一个回应表示反对。 我有一个很好的经验。 谢谢。
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