FIFO and LIFO(Updating)

FIFO

1)SYNCHRONOUS and ASYNCHRONOUS;
   If read and write clock domains are governed by same clock signal, whether one clock signal or two clock signals, the FIFO is said to be SYNCHRONOUS;
   If read and write clock domains are not governed by clock signals FIFO is said to be ASYNCHRONOUS. 

2) Here is an example of Implement FIFI using Verilog

3) FIFO Depth Calculation