实现一个16位CPU。该CPU使用精减指令集，是一个五段流水线的结构。包括取指令(IF)、读寄存器(RD)、运算器(ALU)、内存读写(MEM)和写回(WB)。-The realization of a 16-bit CPU. Streamline the use of the CPU instruction set is a structure of five lines. Including fetch (IF), register read (RD), arithmetic logic unit (ALU), memory read and write (MEM) and Write Back (WB).