The traditional MCS-51 is based on CISC architecture, which executes instructions sequentially and translates instructions to microprogram.

• 传统的MCS-51是基于CISC(Complex Instruction Set Computer,复杂指令集)架构的微控制器,其特点是指令只能依次顺序地执行,且需要微程序对指令进行译码。