Siheyuan starts from the stationmaster

One of these temporary registers is used as a (word-sized) program counter, and its front 6 bits and back 2 bits are used to save the processor status flag (Processor Status Flags).

ARM2可能是全世界最简单实用的32位微处理器，其仅容纳了30，000个晶体管（相较于Motorola六年后的68000其包含了70，000颗）。ARM2工作时钟为8mhz，它的运算能力，比集成了13万个晶体管，最大时钟频率为20mhz的80286更为出色。

At that time, not many people noticed this great chip that was newly released but was destined to go down in history. All the eyes of the industry were focused on the 1985 processor released on October 10, 17.

ARM2的性能虽远超16位元286，但相比于同样32位元的386处理器却显得很寒酸，没能给英特尔公司造成一丝的波澜。

The subsequent processor ARM3 is equipped with a 4KB high-speed cache, so that it can play a better performance.But Intel's 80486 has come out again, and the performance of the two is still not much comparable.

In the late 1980s, Apple Computer began to cooperate with Acorn to develop a new version of the ARM core. Due to the importance of this project, Acorn even formed a new design team called Advanced RISC Machines Ltd. in 1990. company.For this reason, ARM is sometimes called Advanced RISC Machine instead of Acorn RISC Machine.

Since its parent company, ARM Holdings plc, was listed on the London Stock Exchange and NASDAQ in 1998, Advanced RISC Machines became a product owned by ARM Ltd.

This project later entered ARM6, the first version of the style was released in 1991, and then Apple Computer used the ARM6 architecture ARM 610 as the basis for their Apple Newton PDA.In 1994, Acorn used the ARM 610 as the CPU in their Risc PC computer.

In 1993, Acorn successfully developed the ARM7, the most important processor core since the company was established. The power consumption of ARM7 is very low, suitable for handheld applications, and the manufacturing cost is also very cheap.

Just to avoid Intel's patented technology, Acorn can only choose RISC technology that can use less chip resources and fewer developers, but realize a processor chip with relatively high performance.

The instruction set architecture developed by Acorn for its own PC, finally showed its talents in the mobile Internet era 40 years later. ARM microprocessor core technology is widely used in portable communication products, handheld computing, multimedia and embedded solutions Programs and other areas have become the standard for RISC.

But in the field of pc processors, ARM has never surpassed Intel's X86 architecture.The reason is that Intel's influence in the PC field is deeply rooted, and the difference between ARM and the existing x86windows is obvious. In any case, computers with an X86 structure are much faster and stronger than systems with an ARM structure in terms of performance.

Although according to the original development trajectory of the previous life, using ARM and Intel's x86 to head-to-head, the future is gloomy.Bai Zirui did not believe in this evil, because he understood the reason why the ARM in his previous life could not gain a foothold in the PC field.

Those application developers will not spend a lot of research and development energy on a new processor whose life or death is uncertain, as they did with Intel's x86 architecture. If users want to adopt a new processor, they must endure the lack of optional software.

Almost all ARM systems use the Linux operating system, and almost all hardware systems have to build their own systems independently, which is not compatible with other systems, which also makes its application software not easy to transplant, which has seriously restricted the ARM system. development and application.

Acorn's financial situation has been poor, and research and development funds have been very limited, which has created a vicious circle.Backward technology makes it impossible for Acorn to expand R&D investment to catch up with Intel x86.So ARM fell one step behind in the competition with x86, and fell behind step by step, and never got the chance to stand on the same starting line to compete head-on.

In 1990, Apple and Acorn became independent and established a new Acorn Technology. At that time, the new company had only twelve people.It was not until ti and Nokia joined the ARM camp that ARM Technology's financial situation improved, and the number of companies finally reached 1993 in 50.

In fact, the ARM architecture has not kept up with the progress of the Intel x86 architecture from the very beginning. When the ARM architecture gradually smoothed the technological gap between the two, Intel has already erected thick invisible barriers in the PC field. Compatibility issues are enough to discourage potential users.

It is obviously unrealistic for ARM to directly compete with the x86 series in terms of performance. ARM intentionally or unintentionally chose a different design route from Intel - Intel continues to move towards x86 high-performance design, while ARM focuses on low-cost, low-power R&D.

But technology research and development is a very fair field, and only with input can there be output.With such a small number of people in ARM Technology, even if one person can be used as ten people, it is far inferior to Intel, which has thousands of R&D personnel.So ARM later turned to fields such as mobile communications to avoid direct competition with Intel.

Not just ARM, but all other RISC (reduced instruction set) architecture processors have never formed a real threat to Intel in the PC field.Intel's processors have never been technologically advanced. On the contrary, for a long time, every new Intel CPU has been criticized by the industry as useless.

The X86 system is dominated by the Wintel alliance built by Microsoft and Intel, monopolizing the personal computer operating system for nearly 30 years, forming a huge user base, and deeply solidifying the usage habits of many users. Forming a unified standard, almost all x86 hardware platforms can directly use Microsoft's Windows system and almost all popular tools and software, so the x86 system has unparalleled advantages in terms of compatibility.

However, with the advantage of forward compatibility, Intel saves software developers from the cost of developing from scratch. It just relies on CISC (Complex Instruction Set), which is said to be backward and inefficient among all the population, and should be swept into the garbage dump of history, sweeping across the PC field. all competitors. The RISC architecture simply cannot gain a foothold in the field of personal PCs, and finally can only move to the field of workstations and servers.

When Anmou Technology is leading the way in the field of mobile communications, he is unwilling to continue to stay in a corner and is determined to launch an attack on the PC field again, but this time he has to face not only technical competition, but also invisible market monopoly .

Intel has also been ambitious in the field of mobile communications, which is ARM's own land.As a result, both sides failed miserably in trying each other. In a field where the other party has already formed a market monopoly, it is too difficult to gain a foothold.

Bai Zirui knew the development history of the two architectures, and found opportunities for ARM to develop vigorously.On August 1981, 8, before IBM launched the world's first personal computer into the market, the hottest microcomputer in the computer field was undoubtedly Apple's apple series. Apple12 and apple1 used MOS 2 processors, and Intel The 6502 is unobtrusive.

IBM just saw the rapid commercialization of microcomputers represented by Apple, which largely replaced iIBM's mid-range and mainframe markets. In 1979, the company's profit experienced negative growth for the first time.So IBM executives decided to launch a competitive microcomputer to regain the market, which led to the launch of the IBM5150 personal computer.

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