说明：  同步FIFO设计一个同步FIFO，该FIFO深度为16，每个存储单元的宽度为8位，要求产生FIFO为空、满、半满、溢出标志。请采用可综合的代码风格进行编程。
(Synchronous FIFO design a synchronous FIFO, the FIFO depth is 16, the width of each memory cell is 8, required to generate the FIFO is empty, full, half full, the overflow flag. Please use the code can be integrated programming style.)