One of these registers is used as a (word-sized) program counter, the first 6 bits and the last 2 bits of which are used to store the processor status flags (Processor Status Flags).

ARM2 may be the simplest and most practical 32-bit microprocessor in the world. It only accommodates 30,000 transistors (compared to 70,000 transistors in the 68000 six years later). The ARM2 operating clock is 8mhz, and its computing power is more than

The 80286, which integrates 130,000 transistors and has a maximum clock frequency of 20mhz, is even better.

At that time, not many people paid attention to this great chip that was newly released but destined to go down in history. All the eyes of the industry were focused on the 80386 processor released on October 17, 1985.

Although the performance of ARM2 far exceeds that of the 16-bit 286, it is very shabby compared to the same 32-bit 386 processor and failed to make any waves for Intel.

The successor processor ARM3 is also equipped with a 4KB cache, allowing it to perform better. However, Intel's 80486 has already been released, and there is still not much comparison in performance between the two.

In the late 1980s, Apple Computer began to cooperate with Acorn to develop a new version of the ARM core. Because this project was so important, Acorn even formed a new design team in 1990 called Advanced RISC Machines Ltd.

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.

The project later moved into ARM6, with the first version released in 1991, and Apple Computer used the ARM6 architecture ARM 610 as the basis for their Apple Newton PDA. In 1994, Acorn used the ARM 610 as their Risc PC

The CPU in a computer.

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

Precisely in order to avoid Intel's patented technology, Acorn can only choose RISC technology that can use less chip resources and fewer developers to achieve a relatively high-performance processor chip.

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

The research and development direction of consumption.

The x86 system is dominated by the Wintel Alliance built by Microsoft and Intel. It has monopolized the personal computer operating system for nearly 30 years, forming a huge user base and deeply solidifying the usage habits of many users. At the same time, the x86 system has already developed in terms of hardware and software development.

Forming a unified standard, almost all x86 hardware platforms can directly use Microsoft's Windows system and almost all popular tool software, so the x86 system has unparalleled advantages in terms of compatibility.

But technology research and development is a very fair field, and there will be output only if there is investment. With just such a small number of people in Amou Technology, even if one person can be used by ten people, it is far less than having thousands of people.

Intel has a number of R&D personnel. So ARM later turned to mobile communications and other fields to avoid direct competition with Intel.

Acorn's financial situation has been very poor, and its investment in R&D funds has been very limited, which has created a vicious cycle. The backward technology has made it impossible for Acorn to expand its R&D investment to catch up with Intel's x86. As a result, ARM has taken a step forward in the competition with x86.

Falling behind, falling behind step by step, and never getting the chance to compete head-on on the same starting line.

The instruction set architecture developed by Acorn Company for its own PCs finally showed its prowess in the mobile Internet era forty years later. ARM microprocessor core technology is widely used in portable communication products, handheld computing, multimedia and embedded

Solutions and other fields, RISC has become the standard.

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

ARM systems almost all use Linux operating systems, and almost all hardware systems have to build their own systems separately, which are incompatible with other systems. This also results in the inability of its application software to be easily transplanted, which has always seriously restricted the ARM system.

development and application.

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

Not just ARM, but all other RISC (reduced instruction set) architecture processors have never posed a real threat to Intel in the PC field. Intel's processors have never been technologically leading. On the contrary, for a long time,

Every new CPU from Intel is criticized by the industry as useless.

In 1990, Apple and Acorn became independent and established a new ARM 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 people in the company

Finally, in 1993, the number of people reached 50.

In fact, the ARM architecture has never kept up with the progress of Intel's x86 architecture from the beginning. When the ARM architecture slowly smoothed the technological gap between the two, Intel had already erected thick invisible barriers in the PC field. Just software

Compatibility issues are enough to deter potential users.

However, Intel relied on the advantage of forward compatibility to save software developers from the cost of research and development from scratch. Instead, it relied on CISC (Complex Instruction Set), which everyone said was backward and inefficient and should be swept into the garbage heap of history, to sweep the PC field.

All competitors were eliminated. The RISC architecture simply could not gain a foothold in the field of personal PCs, and finally had to move to the field of workstations and servers.

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. The difference between ARM and existing x86 windows is obvious. X86-structured computers are better than ARM-structured computers anyway.

The system is much faster and more powerful in terms of performance.

When Arm Technology took the lead in the field of mobile communications, it was unwilling to continue to be content and determined to launch an attack on the PC field again. But this time it had to face not only technical competition, but also an invisible market monopoly.

.

Intel has also been ambitious in the field of mobile communications, which is ARM's exclusive territory. As a result, both parties failed miserably in trying each other. It is too difficult to gain a foothold in a field where the other party has formed a market monopoly.

Bai Zirui knew the development history of the two architectures and discovered the opportunity for ARM to develop vigorously. Before IBM launched the world's first personal computer on August 12, 1981 and put it on the market, the most popular microcomputer in the computer field was undoubtedly Apple.

The company's apple series, apple1, and apple2 all use MOS 6502 processors, and Intel's 8086 is not conspicuous.

IBM saw the rapid commercialization of microcomputers represented by Apple, which largely replaced IBM's mid-sized computers and mainframes in the market. The company's profits experienced negative growth for the first time in 1979. So IBM executives decided to launch a

Competitive microcomputers regained the market, and this led to the launch of the IBM 5150 personal computer.
Chapter completed!