The relationship between instruction set architecture, arm core, SoC, processor, CPU, GPU, etc.

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The relationship between instruction set architecture, arm core, SoC, processor, CPU, GPU, etc. [Copy link]

ARM cores include: ARM7, ARM9, ARM11 (v6), to cortex-A7, A8, A9, A12, A15 (v7-A/R), to cortex-A53, A57 (V8), A72, A73. The cache is in the core [4]. These cores are also known as public version architectures, that is, the general architecture launched by ARM. SoC chips include: Qualcomm's Snapdragon 820, 821, 835; Kirin 950 (4XCortex-A72+4XCortex-A53), 960 (4*Cortex-A73+4*Cortex-A53); MediaTek's HelioX20, X25, X30; Samsung's Exynos8890, 7420, 5433, etc. There are also STM32 (based on ARM cortex M3 core) Again, the processor we are talking about now is no longer the CPU in the past. To be precise, it should refer to SoC. SoC (System on Chip): It is called a system-level chip, also known as a system on a chip, which means that it is a product, an integrated circuit with a proprietary target, which contains all the contents of a complete system and embedded software. The official definition is to integrate a microprocessor, an analog IP core, a digital IP core and a memory (or an off-chip storage interface) on a single chip. - To make a simple analogy, if the CPU is regarded as the brain of the human body, then the SoC is the total body of our human body (including various organs and tissues). That is, GPU, bus, display accelerator, ISP, video codec, audio processor, memory controller, sensor processing unit, and external interfaces such as DDR, Flash, display interface, Camera interface, RF, USB, etc. These components should be integrated together to form a whole. In addition, it is necessary to ensure that the various components can coordinate and operate stably. The R&D costs invested in such design technology are not acceptable to every manufacturer [2]. ARM itself does not participate in the manufacture and sale of terminal processor chips, but earns revenue by licensing design solutions to other chip manufacturers. For example, if the processor is equivalent to a complete building, ARM is like the frame of the building. As for what the final house looks like and how comfortable it is, it is up to the processor manufacturer to decide. However, processors with the same architecture have basically locked their performance within a certain range and will not have any essential differences. Therefore, to see the performance of a processor, you must first look at the microarchitecture [3]. ARM provides two types of CPU licenses: core instruction set licenses and ready-made CPU core design licenses [2][3]. Most mobile phone processor manufacturers in the industry choose to directly purchase ARM CPU core designs and then integrate them with other components (such as GPUs, multimedia processing, modems, etc.) to create a complete SoC system-on-chip. These off-the-shelf CPUs are all based on the ARM Cortex A5, A8, A9, and even A15 microarchitectures. Or they are customized and modified based on the existing architecture. For example, Samsung's Hummingbird core is modified based on the Cortex-A8. In 2011, Samsung officially launched the Exynos4 Dual 4210 chip (Dual stands for dual-core) and the corresponding new flagship phone Galaxy SII. At the same time, the "Hummingbird" was renamed Exynos3 Single 3110 (single stands for single-core), which was the beginning of the Exynos family. In the first quarter of 2016, Samsung released the Exynos8 Octa 8890 (Octa stands for 8 cores). It has a very important significance - this is Samsung's first ARM chip with a self-developed architecture [22]. Note that after my research, the so-called self-developed architecture, which can also be called self-developed microarchitecture, is actually a public version of the core similar to cortex-A53, A73, etc., which is also called a public version microarchitecture. However, there are also a few mobile processor manufacturers, such as Qualcomm, which directly develop their own processor microarchitecture based on the ARM v7 instruction set, such as Qualcomm's Scorpion and Krait, and then design their own CPUs with greater flexibility. The roles of Scorpion and Krait are similar to those of cortex A53 and cortex A57 and ARMv7 and v8[6]. Scorpion is a modification of Qualcomm based on Cortex-A8. Its key feature is that it is about 30% more energy-efficient at the same frequency. The current Snapdragon 820 and 835 use the Kryo architecture[27]. The 820 is Kryo, and the 835 is its upgraded version Kryo280. Off topic: Huawei obtained ARM's architecture license as early as 2013, which means that Huawei can modify ARM's original architecture and expand or reduce the instruction set. From 2013 to now, Huawei Kirin processors have been updated from 910 to 960. According to Huawei's persistence in technology and passion for exploring unknown areas. They have no reason not to transform and optimize the original ARM architecture and add their own unique understanding of the architecture. In other words, the A53+A72 architecture used in Huawei Kirin processors already has its own technology and innovation (this innovation is similar to the small changes made by Samsung Hummingbird to Coretex-A8). In fact, the architecture used by Apple processors is also evolved from the ARM architecture. Therefore, Huawei Kirin processors will definitely have their own architecture in the future, but this requires a long period of research and development and technology accumulation. That is: launching things like Qualcomm's Scorpion, Krait, Kryo, Samsung's Mongoose, Apple's Swift (based on ARMv7), Cyclone, TYphoon, Twister, and Nvidia's Denver.