怎么测量硬件中脉冲之间的时间

我想测量两个上升沿之间的时间来计算霍尔效应传感器的速度（300万转/分钟）。
理想情况下，我想要一个上升计数器，它会在上升沿捕获到一个后进先出缓冲器或一个寄存器，然后重新装入计数器。
问题是，唯一可用的计数器使用FIFO缓冲器，这些缓冲器覆盖到缓冲器的前面，使得很难说哪一个值是最新的值。如果缓冲区没有溢出，那么最新的值在后面。但是，如果缓冲区已经溢出，那么最新的值就在前面。但是，由于没有溢出状态位，所以在每次捕获时，我将被迫中断处理器，以确保FIFO缓冲区不溢出。我不想经常中断处理器。有没有办法避免使用中断，避免使用轮询，并且避免为自己的计数器编写VHDL？谢谢您。



     以下为原文
  I would like to measure the time between two rising edges to calculate speed with a hall effect sensor (30000rpm).
Ideally, I would like an up-counter that would capture on a rising edge to a LIFO buffer or single register and then reload the counter.
The problem is that the only counters available use FIFO buffers that overwrite to the front of the buffer, making it hard to tell which value was the latest value. If the buffer has not overflown, then the newest value is at the back. However if the buffer has overflown, then the newest value is at the front. However, since there is no overflow status bit, I would be forced to interrupt the processor on every capture to make sure the FIFO buffer does not overflow. I do not want to have to interrupt the processor so often. Is there a way to avoid using interrupts, avoid using polling, and avoid writing VHDL for my own counter? Thank you.