ARM is a family of Reduced Instruction Set Computer (RISC) based processor architecture, configured for almost every environment. By Acorn Computers Ltd., ARM was founded in 1983 by the name of Acorn RISC Machine. It changed its name to Advanced RISC Machine in 1990. Since 1998, the company has been recognized as ARM Ltd.
Contrary to popular belief, ARM company does not produce processors. It only plays a role in the design and licensing of processor architectures. The companies that buy the licenses then produce the processors by making some customizations according to the intended use. Manufacturing companies have the opportunity to customize processors according to themselves. Therefore, some differences can be observed between processors of different manufacturers with the same architecture.
Figure 1: Acorn Computers Ltd. Logo 
Figure 2: Arm Holdings Logo 
Computer company Acorn Computers Ltd., founded in Cambridge, England in 1978, produced a group of computers such as Acorn Electron and Acorn Archimedes, which are particularly popular in the UK. The BBC Micro computer, introduced by Acorn in December 1981, was the company’s first large-scale successful design.
The company introduced the company’s first RISC-based processor architecture prototype ARM1 (Acron RICS Machine – 1), which was developed as an R&D project in 1985. Then, in 1986, the company introduced its first real product, the ARM2 architecture.
In the late 1980s, Apple began working with Acorn on new versions of the ARM architecture and VLSI Technology became the first investor and licensee to join these two companies. In 1990, Acorn transformed its design team into a new company named Advanced RISC Company.
As a result of the new Apple-ARM work, firstly the new processor architecture ARM6 was introduced in early 1992. Apple used the ARM6-based ARM610 processor as the basis for their Apple Newton PDA devices.
In 1998, Advanced RISC Machines Ltd. took the name ARM Ltd., with its parent company Arm Holdings Plc. floating on the NASDAQ and the London Stock Exchange.
In 2005, about 98% of mobile phones on the market used ARM architecture processors. In 2010, ARM-based chip manufacturers reported that 6.1 billion ARM-based processors were produced, which corresponds to 95% of smartphones, 35% of digital televisions and set-top boxes, and 10% of mobile computers. In 2011, the 32-bit ARM architecture was the most widely used processor architecture in mobile devices. It was also the most popular 32-bit architecture in the embedded systems branch. In 2013, the production has reached to 10 billion, and also ARM-based chips accounted for approximately 60% of mobile devices in the world.
By 2016, the company had an important place in the London Stock Exchange and NASDAQ. It was also part of the FTSE 100 Index. On July 18, 2016, SoftBank Group, a Japanese telecommunications company, made an offer worth £ 24.3 billion, subject to the approval of ARM shareholders. Then on September 5, 2016, it acquired ARM. On September 13, 2020, Nvidia, the leader of the graphics industry, announced that it purchased the ARM company from Softbank for $ 40 billion.
Figure 3: ARM in partnership 
As I mentioned at the beginning, ARM is a 32-bit RISC based processor architecture family. ARM-based processors with 32-bit architecture, high speeds, low power consumption and rich peripheral hardware; It is preferred in many areas such as mobile devices, computers, real-time systems, smart home appliances.
Figure 4: ARM cores 
The seventh version of the architecture, ARMv7 and later versions, comes with three different architectural profiles:
- Profile-A: The “Application” profile is used by 32-bit cores in the Cortex-A series cores. The A-Profile processor family is developed to be used in high technology applications where high speed is needed such as mobile devices and computers. For example, Apple’s A14 Bionic chip developed by Apple for iPhone 12 has a microprocessor with ARMv8.6-A architecture.
- Profile-R: The “Real-time” profile is used by cores in the Cortex-R series. R-Profile processor family is developed for use in computer controlled systems where very low latency and high security are required, such as electronic brake systems in automobiles.
- Profile-M: The “Microcontroller” profile is used by most cores in the Cortex-M series. The M-Profile processor family is designed for use in microcontrollers, ASICs, ASSPs, FPGAs and SoCs.
- Wikipedia. ARM Architecture
- Wikipedia. Acorn Computers
- Wikipedia. ARM Ltd
- Wikipedia. ARM Cortex-A
- Wikipedia. ARM Cortex-R
- Wikipedia. ARM Cortex-M
- ARM Ltd. Website
- Watelectronics. ARM Processor Architecture Working
- Chuang, Y. ARM Architecture