基于格雷码的深度可配置的异步FIFO设计实现

摘要

如何防止产生亚稳态问题，更好地同步异步信号及准确地设计空、满、几乎空、几乎满控制信号的产生是异步FIFO设计的两大难点。介绍了一种异步FIFO的设计方法，用先比较读写地址产生空满标志，再同步到相应的时钟域的方法来准确设计标志位信号的产生。采用格雷（Gray）码来避免亚稳态的出现，性能较稳定，并比较了利用Gray码、单步循环码作异步FIFO指针的优缺点。最后，给出了系统的仿真及综合结果。%How to prevent metastability, and better synchronous asynchronous signals to accurately design empty, full, alempty, alfull control signal which are the two major dififculties. The paper introduce a method of asynchronous FIFO design, ifrst comparing the reading and wirting address to generate empty and full lfag, secondly, synchronous to the corresponding clock domain approach to accurate the lfag accurately. The Gray code can avoid the emergence of metastability and get more performance. And the paper also analyze the Gray code and signal step cyclic code advantages and disadvantages to produce the iffopointer. Finally, the paper show the system simulation and DC results.