The Principle and Applications of Asynchronous FIFO

With the rapid development of integrated circuits, a complete system of integrated Circuits contains multiple clocks in a chip. Under the control of different clock domains, data can become metastable state between transfers or storage. This paper describes one of the effective methods to solve the problem about the metastable state, the method is asynchronous FIFO. We study Synchronous FIFO and Asynchronous FIFO in this paper. The article analyses the reasons for the emergence of sub-stability metastable state and how to use the Gray Code to solve metastable state problems effectively. We can generate empty/full status bits via Gray Code pointer, it can effectively reduce the probability of metastable state. This paper has the significance of guiding the use of FIFO.