1、MCS-8051系列单片机字长是 8 位，有 40 根引脚，96系列字长是 16 位。单片机的特点有 体积小、价格低、功能全 。

2、8051单片机的存储器的最大特点是 指令存储器与数据存储器分开编址 ，Px并行口的地址是与 数据 存储器统一编址的，或者说属于该存储器。

-1, MCS-8051 Series Single-chip 8-bit word length is, there are 40 pin, 96 series of word length is 16. MCU features small size, low cost, full-featured. 2,8051 biggest single-chip memory is characterized by instruction memory and data memory addressing separately, Px parallel port address is unified with the data memory addressing, or belong to the memory.