计算机的控制器可分为组合逻辑控制器和微程序控制器两大类。本刊前两期分别介绍了一台模型机的指令系统和组成结构的设计以及模型机指令流程的设计。在此基础上,要用微程序方法构造控制器首先必须进行微指令格式的设计。微指令分为微命令字段和次地址字段,本文将先介绍这台模型机的微指令格式。 Computer controller can be divided into combinatorial logic controller and micro-controller two main categories. The first two issues of this magazine respectively introduced the design of a command system and component structure of a model machine and the instruction flow of a model machine. On this basis, to use micro-program method to construct the controller must first micro-instruction format design. Microinstruction is divided into micro-command field and sub-address field, this article will first introduce the micro-command format of this model machine.