Soft test (5)-CPU composition of computer systems

In fact, we have been familiar with computer systems for a long time, but we are still confused and cannot understand clearly. This part of knowledge requires us to spend a lot of time understanding it, because we cannot reach out to many things, such as the verification code and code system. If you don't understand it, but remember it, it will be difficult to understand the principle, besides, I cannot remember it.

First, this part of content can be divided into three major parts: Basic knowledge, architecture and evaluation.

The first part first introduces the basic knowledge of computer composition principles, including hardware composition, CPU composition, computer code system and verification code. After introducing the basic knowledge, we enter the core part-architecture. The architecture introduces the storage system, input and output technology, and bus structure. If you do not understand why you have introduced these aspects, you can see the following figure.

After introducing the core knowledge of computer systems, the third part focuses on how to ensure security and improve reliability and performance.

CPU composition is a common test site, the CPU is mainly composed of the memory, controller, register group and internal bus.

1. Timer

Before reading the preceding figure, you must understand the basic abbreviations, even if you do not know the abbreviations. At least you need to know that "A" in ALU and AC is the meaning of arithmetic (arithmetic and arithmetic operations.
1) in the memory, assume that you start to execute an operation 2 + 7 and put 2 in the AC first. The AC provides a work zone for ALU, then extracts 7 from the memory, and then sums up, the result is returned to the AC.

2) Dr is a data buffer register. It is a temporary storage space for each read or write operation on the memory. It is only temporarily stored. We will continue to describe it below.

3) The psw contains the content of various condition codes.

2. Controller

Note: To make the interface clearer, the detailed internal BUS is not drawn.

Note:

1) when the CPU executes an instruction, it first reads it from the internal memory to the DR, and then sends it to the IR. Then, the instruction decoder generates various operation instructions based on the IR content, complete the required functions.
2) PC (program counter): the CPU automatically modifies the content so that the address of the next instruction is always maintained. That is, add 1 to the PC to track the command address.
3) Ar ("A" is adress) saves the address of the memory unit accessed by the current CPU.

3. Register Group
There are two types: Private and general.

Registers in the memory and controller are specialized registers, such as AC and AR. Their functions are fixed. General registers are widely used and can be specified by programmers.

The following graphic is a summary of computer system knowledge:

Conclusion: you are not afraid of understanding and making mistakes. Welcome to O (∩ _ ∩) O ~

Soft test (5)-CPU composition of computer systems