The advantages and design of the microprogram controller, the microprogram controller is easy to design, simple in structure, easy to modify or expand, modify the function of a machine instruction, only need to reprogram the corresponding microprogram; to add a machine instruction, only It is necessary to add a microprogram to the control memory, but it is done by executing a micro pass. The specific comparison is as follows: The combination logic controller, also known as the hard wiring controller, is composed of logic circuits, and the functions of the instructions are completely realized by hardware.

The microprogram controller design steps:

1. Design the instruction system of the machine: specify the type of instruction, the number of instructions, and the format and function of each instruction;

2, the initial overall design: such as register settings, bus arrangements, operator design, connection between components, etc.;

3. Drawing instruction flow chart: indicate when and what component of each instruction is performed;

4. Arrange the operation schedule: that is, according to the instruction flow chart, the operations are decomposed into micro-operations, and the micro-operations that the machine should perform are listed according to the time period;

5, list micro-operation signal expressions, simplification, circuit implementation.