Introduction - If you have any usage issues, please Google them yourself
The first three examples illustrate the difference between RTL FSMD model (Finite State Machine with Datapath buildin) and RTL FSM + DataPath model. From view of RT level design, each digital design consists of a Control Unit (FSM) and a Datapath. The datapath consists of storage units such as registers and memories, and combinational units such as ALUs, adders, multipliers, shifters, and comparators.