1. Features of von Neumann computer
① Five major components: arithmetic unit, controller (controlling what kind of calculations are performed), memory, input device, and output device.
②Instructions and data are stored in the memory with the same status and can be accessed by address.
③Instructions and data are expressed in binary.
④ The instruction is composed of operation code and address code.
⑤ Store the program. Machines with the characteristics of stored programs are called Von Neumann machines.
⑥ Centered on arithmetic unit.
Hardware block diagram of von Neumann computer
The solid line represents the data signal, and the dashed line represents the control signal.
For example, if the data is to be retrieved from the memory, it needs to send a sub-signal to the controller, and the controller can output the control signal after the feedback.
- Operator: Arithmetic operation, logical operation.
- Memory: store data and programs.
- Controller: Command and control the operation of the program.
- Input device: Convert the signal into a form that the machine can recognize.
- Output device: Convert the result into a familiar form.
2. Computer hardware block diagram
① Defects of von Neumann machine: It is based on arithmetic unit, and the block diagram is messy and has no hierarchy.
② Improvement 1: Change to a memory-centric computer.
The double line indicates the transmission of data.
The improved block diagram still looks levelless.
② Improvement 2: Modern computer hardware block diagram.
As can be seen from the analysis of the above figure, a hierarchical structure can be used to represent the computer's structural block diagram.
As shown in FIG.
③Methods of system complexity management: (3'Y)
- Hierarchy: Divide the designed system into multiple modules or sub-modules.
- Modularity: There are clearly defined functions and interfaces.
- Regularity: Modules are easier to reuse.