Silicon wafer preparation: the so-called silicon wafer preparation is to extract and purify the silicon from the sand, then make a silicon ingot with an appropriate diameter through a series of special processes, and then cut the silicon ingot into thin slices.

Silicon wafer manufacturing: This is the second stage of microchip manufacturing. The exposed silicon wafer arrives at the silicon wafer factory and goes through the steps of cleaning, film formation, photolithography, doping and so on.

Silicon wafer testing/sorting: after the silicon wafer is manufactured, each chip is tested and electrically tested to distinguish between qualified and unqualified chips. Stick the defective chip on the label to prevent the defective chip from being sent to the customer.

Assembly and packaging: the step of assembling and packaging qualified chips, that is, packaging a single chip in a protective shell.

Final test: This is the last process of packaging the chip and sending it to the customer. In order to ensure the function of the chip, each chip should be tested for integrated circuits to meet the requirements of various parameters and use environment. After the final test is qualified, the chip will be sent to the user.

CPU composition structure:

CPU includes arithmetic logic unit, register unit, arithmetic unit and control unit.

arithmetic logic unit

The arithmetic logic unit can perform fixed-point or floating-point arithmetic operation, shift operation and logic operation, and can also perform address operation and conversion.

Register unit

The register part includes general register, special register and control register.

General registers can be divided into fixed-point and floating-point numbers, which are used to store register operands and operation results in instructions.

General register is an important part of central processing unit, and most instructions need to access general register. The width of the general register determines the width of the internal data path of the computer, and the number of its ports often affects the parallelism of internal operations.

Special registers are registers needed to perform some special operations.

Control registers are usually used to indicate the state of machine execution or save some pointers, including processing state registers, base address registers of address translation directories, privileged state registers, condition code registers, exception handling registers and error detection registers.

Sometimes, there will be some caches in the CPU to temporarily store some data instructions. The larger the cache, the faster the CPU will run. At present, the secondary cache of high-end CPU in the market is about 2M, and that of high-end CPU is about 4M.

Control unit

The control unit is mainly responsible for decoding instructions and sending control signals for each operation to be performed by each instruction.

There are two structures: one is microprogrammed control mode with micro-memory as the core; One is the control mode based on logical hard wiring structure.

Micro-memory stores microcode, and each microcode corresponds to a basic micro-operation, also called micro-instruction; Each instruction consists of different microcode sequences, which constitute a microprogram. After the instruction is decoded, the central processor sends out a control signal with a certain time sequence, and executes several micro-operations determined by these microcode in a given order with a micro-cycle as the beat, thus completing the execution of an instruction.

Simple instructions consist of (3 ~ 5) micro-operations, while complex instructions consist of dozens or even hundreds of micro-operations.