计数器专用时间段

好。
假设你想要4 us，你有一个125 MHz的时钟（8 ns周期）。
那么你将需要4 us / 8 ns = 500个时钟周期。
所以，我们将判断：常数C_FOUR_MICROSECONDS：整数：= 500;
现在我们需要我们的计数器：signal counter4u：整数范围0到C_FOUR_MICROSECONDS-1：= 0;
然后，您将有一个进程，在计数器启用的每个时钟周期递增计数器（如果它将永久启用，忽略启用行或永久设置为'1'：
P_INCREMENT_COUNTER：进程（时钟）是
开始 
如果rising_edge（时钟）那么 
if（enable ='1'）然后 
counter4u 
其他 
counter4u 
万一; 
万一;
结束过程P_INCREMENT_COUNTER;
然后你可以有一个单独的过程来检测计数周期的结束（你可以把它放在同一个过程中，如果你想 - 我喜欢将它们分开。
P_COUNTER_DETECT：进程（时钟）是
开始 
如果rising_edge（时钟）那么 
if（counter4u = C_FOUR_MICROSECONDS-1）然后 
count_end 
其他 
count_end 
万一; 
万一;
结束过程P_COUNTER_DETECT;
您可以以几乎完全相同的方式构建边缘检测计数器。
----------“我们必须学会做的事情，我们从实践中学习。”
- 亚里士多德
在原帖中查看解决方案



以下为原文

OK. Let's say you want to count for 4 us and you have a 125 MHz clock (8 ns period). Then you will need 4 us/ 8 ns = 500 clock cycles.
 
So, we'll decare: constant C_FOUR_MICROSECONDS : integer := 500;
 
Now we need our counter: signal counter4u : integer range 0 to C_FOUR_MICROSECONDS-1 := 0;
 
Then you will have a process that increments the counter for every clock cycle it is enabled (if it will be permanently enabled, ignore the enable line or set it permanently to '1':
 
P_INCREMENT_COUNTER : process(clock) is
begin
  if rising_edge(clock) then 
    if (enable = '1') then
      counter4u <= (counter4u + 1) mod C_FOUR_MICROSECONDS;
    else
      counter4u <= 0;
    end if;
  end if;
end process P_INCREMENT_COUNTER;
 
Then you can have a separate process to detect the end of the counting period (you could put it in the same process if you wanted - I like to keep them separate.
 
P_COUNTER_DETECT : process(clock) is
begin
  if rising_edge(clock) then
    if (counter4u = C_FOUR_MICROSECONDS-1) then
      count_end <= '1';
    else
      count_end <= '0';
    end if;
  end if;
end process P_COUNTER_DETECT;
 
You can build you edge detect counter in almost exactly the same way.
----------
"That which we must learn to do, we learn by doing." - AristotleView solution in original post

1.不要使用计数器来生成时钟。
只是不要。
2.不要使用ieee.std_logic_unsigned。
只需使用numeric_std
3.使用原始125 MHz作为系统时钟没有错。
4.将脉冲输入与系统时钟同步（如果它与系统时钟异步）。
5.检查同步脉冲输入的边沿以增加脉冲计数器。
*请勿使用rising_edge（信号）来执行此操作！*
同步设计！
----------“我们必须学会做的事情，我们从实践中学习。”
- 亚里士多德



以下为原文

1. Don't use counters to generate clocks. Just don't.
2. Don't use ieee.std_logic_unsigned. Just use numeric_std
3. Nothing wrong with using your original 125 MHz as the system clock.
4. Synchronise your pulse input to your system clock (if it is asynchronous to your system clock).
5. Check for edges of your synchronised pulse input to increase your pulse counter. *Do not use if rising_edge(signal) to do this!*
 
Synchronous design!  
 
----------
"That which we must learn to do, we learn by doing." - Aristotle

你好@ hgleamon1
withie.std_logic_unsigned有什么问题。
当我删除它时，由于计数器中的总和，我得到了错误。
我看到了一些与脉冲计数有关的方法叫做edge_detector。
可能这会完成我的工作。
提前致谢。



以下为原文

 
Hi @hgleamon1 
 
What is the problem with ieee.std_logic_unsigned. when I remove it I got erros because of summattion in the counters. I saw some other methods related to pulse counting called edge_detector. Probably this will do my job.
 
 
Thanks in advance.

尽管它的名字，ieee.std_logic_unsigned不是标准的。
它是一个旧的Synopsys库，完全由实际标准ieee.numeric_std替换（在功能上）。
您可能会因为尝试向std_logic_vector添加值而得到错误，例如
“0001”+ 1，这是不可能的。
最好对计数器使用整数，首先是因为它更容易阅读，其次因为它完全受到numeric_std包的支持。
如果您需要非常大的数字，那么您应该使用与numeric_std完全兼容的有符号或无符号类型。
----------“我们必须学会做的事情，我们从实践中学习。”
- 亚里士多德



以下为原文

Despite its name, ieee.std_logic_unsigned is not standard. It is an old Synopsys library that is entirely replaced (in function) by the actual standard ieee.numeric_std.
 
You probably get errors because you try to add a value to a std_logic_vector, e.g. "0001" + 1, which is not possible.
 
It is better to use integers for counters, firstly because it is easier to read and secondly because it is entirely supported by the numeric_std package. If you need very large numbers then you should use signed or unsigned types that are also fully compatible with numeric_std.
----------
"That which we must learn to do, we learn by doing." - Aristotle

当我改变计数器声明
信号计数器：STD_LOGIC_VECTOR  - >信号计数器：INTEGER
我又得到了错误。
我在谷歌上查了一个例子，但我找到的是使用std_logic_vector。
你能给出一个链接或一个例子吗？
谢谢



以下为原文

When I change the counter declaration
 
signal counter : STD_LOGIC_VECTOR -> signal counter : INTEGER
 
I got error again. I checked for an example on the google but the ones I found were using std_logic_vector. Could you give a link or an example?
 
Thanks

好。
假设你想要4 us，你有一个125 MHz的时钟（8 ns周期）。
那么你将需要4 us / 8 ns = 500个时钟周期。
所以，我们将判断：常数C_FOUR_MICROSECONDS：整数：= 500;
现在我们需要我们的计数器：signal counter4u：整数范围0到C_FOUR_MICROSECONDS-1：= 0;
然后，您将有一个进程，在计数器启用的每个时钟周期递增计数器（如果它将永久启用，忽略启用行或永久设置为'1'：
P_INCREMENT_COUNTER：进程（时钟）是
开始 
如果rising_edge（时钟）那么 
if（enable ='1'）然后 
counter4u 
其他 
counter4u 
万一; 
万一;
结束过程P_INCREMENT_COUNTER;
然后你可以有一个单独的过程来检测计数周期的结束（你可以把它放在同一个过程中，如果你想 - 我喜欢将它们分开。
P_COUNTER_DETECT：进程（时钟）是
开始 
如果rising_edge（时钟）那么 
if（counter4u = C_FOUR_MICROSECONDS-1）然后 
count_end 
其他 
count_end 
万一; 
万一;
结束过程P_COUNTER_DETECT;
您可以以几乎完全相同的方式构建边缘检测计数器。
----------“我们必须学会做的事情，我们从实践中学习。”
- 亚里士多德



以下为原文

OK. Let's say you want to count for 4 us and you have a 125 MHz clock (8 ns period). Then you will need 4 us/ 8 ns = 500 clock cycles.
 
So, we'll decare: constant C_FOUR_MICROSECONDS : integer := 500;
 
Now we need our counter: signal counter4u : integer range 0 to C_FOUR_MICROSECONDS-1 := 0;
 
Then you will have a process that increments the counter for every clock cycle it is enabled (if it will be permanently enabled, ignore the enable line or set it permanently to '1':
 
P_INCREMENT_COUNTER : process(clock) is
begin
  if rising_edge(clock) then 
    if (enable = '1') then
      counter4u <= (counter4u + 1) mod C_FOUR_MICROSECONDS;
    else
      counter4u <= 0;
    end if;
  end if;
end process P_INCREMENT_COUNTER;
 
Then you can have a separate process to detect the end of the counting period (you could put it in the same process if you wanted - I like to keep them separate.
 
P_COUNTER_DETECT : process(clock) is
begin
  if rising_edge(clock) then
    if (counter4u = C_FOUR_MICROSECONDS-1) then
      count_end <= '1';
    else
      count_end <= '0';
    end if;
  end if;
end process P_COUNTER_DETECT;
 
You can build you edge detect counter in almost exactly the same way.
----------
"That which we must learn to do, we learn by doing." - Aristotle

你好@ hgleamon1
非常感谢您的贡献。
我搞定了:)
现在尝试进一步改进并行源/计数器......



以下为原文

Hi @hgleamon1
 
Thank you very much for the contribution. I got it working :) 
 
Now trying to improve it further for parallel sources/counters...