说明：  FPGA中同步FIFO的使用小结，FPGA中的FIFO，分为同步FIFO，异步FIFO和双向FIFO。同步FIFO一般用于数据的缓存，异步FIFO一般用于跨时钟域的同步上。
(FPGA use in synchronous FIFO summary, FPGA' s FIFO, divided into synchronous FIFO, Asynchronous FIFO and two-way FIFO. Generally used for data synchronization buffer FIFO, asynchronous FIFO generally used for synchronization across clock domains on the.)