The CPU is the core and brain of the computer system, mainly composed of a controller, arithmetic, memory and connection bus. Among them, the controller and the combinator form the core of the CPU, the core extracts data from the memory, decodes the data according to the instruction set in the controller, calculates the result through the microarchitecture (circuit) in the combinator, and writes the execution result to the memory in a certain format.
CPUs are divided into two categories: CISC complex instruction set and RISC reduced instruction set according to the architecture of instruction set. CISC designers wanted to make programming easier and programs faster by building complex instructions directly into the hardware, with each instruction performing several low-end operations, such as reading from memory, storage, and computation, all in a single instruction; In contrast, the RISC architecture contains only a small number of simple instructions that are used frequently, and provides some necessary instructions to support the operating system and high-level languages.
The CISC camp is represented by Intel, AMD's x86 architecture, while the RISC camp includes ARM, MIPS, Power PC and other architectures.
1) From a hardware point of view, CISC processes unequal length instruction sets, while RISC executes equal length reduced instruction sets, and RISC is significantly better than CISC in parallel processing. Because RISC executes a reduced instruction set, it requires fewer transistors at the hardware level than CISC, so its hardware manufacturing process is simpler and cheaper. RISC-type CPUs are not software and hardware compatible with CISC CPUs, which is determined by the characteristics of the instruction set.
2) From a performance point of view, CISC and RISC are not absolutely superior or inferior. However, in the process of development, Intel and AMD in the CISC camp have made continuous efforts to improve chip performance, and the power consumption of the chip has been placed in the second place after performance; RISC itself appeared about ten years later than CISC (ARM was born in 1985, X86 was born in 1978), ARM and MIPS lacked the strength to compete with Intel products in the early days of their founding, focusing on high-performance chips with low power consumption.
The RISC camp's Power PC architecture was originally designed for personal computer products, but it appeared in 1992, when Intel's 80386 and 80486 dominated the PC market. The following year, Intel's famous Pentium series was released and helped Intel capture the vast majority of the PC market, which was the fifth generation of CISC-based x86 architecture microprocessors, which Intel named "Pentium". Throughout the mid-1990s, PowerPC processors met or exceeded benchmark scores for the fastest x86 CPUs. However, because PowerPC had an extreme lack of application software for Windows, OS/2, and Sun customers, it did not end up splashing in the PC market. But then Apple used PowerPC processors in the Macintosh personal computer series because of the higher performance of the PowerPC processor. In 2005, Apple announced that it would no longer use PowerPC processors in its Apple Macintosh computers due to calorific and energy consumption considerations, and would instead support processors made by Intel. Since then, PowerPC has begun to evolve in the direction of ultra-high-performance servers.
3) CISC and RISC have gradually converged, and the processors of the two parties learn from each other and optimize each other. For example, Intel's Pentium Pro includes three decoders capable of translating x86 instructions into 118-bit fixed-length RISC-style micromanipulation.
4) Overall, in the field of mobile chips, ARM architecture chips occupy more than 90% of the market share, and in the computing CPU market, Intel X86 processors occupy more than 90% of the market share. Although MIPS and Power are no longer mainstream, some vendors still use them.
5) There is still a gap between domestic CPUs and X86 products, which are mainly reflected in: 1) professional talents are the bearer of technology and level, and the number of domestic professional talents is small and the overall scale is still small; 2) Hard power, including software and hardware design and development environment, EDA, etc., there are shortcomings; 3) There are gaps in soft power, including CPU design methodology, CPU design process and specifications.
Regarding the development status of domestic CPUs, China has started processor design projects since 200, and for nearly 20 years, domestic CPUs represented by Zhongke Longxin, Tianjin Feiteng, Haiguang Information, Shanghai Shenwei, Shanghai Zhaoxin, etc. have been produced and the performance of products has improved year by year, and the application fields have been expanding, so that China's long-term situation of no "core" has been greatly reversed, laying the foundation for building a secure, autonomous and controllable localized computing platform. At present, there are six major domestic CPU manufacturers.
