ARM Cambridge has a long and storied history as one of the pioneers in RISC processor technology. The company was founded in 1990 as a joint venture between Acorn Computers, Apple, and VLSI Technology. The aim was to commercialize the reduced instruction set computing (RISC) processor technology that Acorn had developed for its Archimedes personal computer in the 1980s.
The origins of ARM
The origins of ARM date back to the early 1980s when Acorn Computers was working on a successor to its successful BBC Micro home computer. Acorn engineers recognized the performance limitations of traditional complex instruction set computing (CISC) microprocessors and believed a RISC architecture could provide higher performance at lower cost and power. This led to the development of the Acorn RISC Machine (ARM) processor for use in Acorn’s new Archimedes computer.
The first ARM processor, the ARM1, was designed in 1985 by Sophie Wilson and Steve Furber. It had a simple 32-bit RISC architecture with just 27 instructions. Despite its simplicity, the ARM1 could outperform more complex CISC processors. The follow-on ARM2 in 1986 increased performance significantly while adding a multiplier and embedded DRAM controller.
Commercialization of ARM
With the success of the Archimedes computer, Acorn recognized the potential to commercialize its ARM technology and capitalize on the rapidly growing market for embedded RISC processors. This led to the formation of Advanced RISC Machines Ltd in 1990 as a joint venture between Acorn, Apple, and chipmaker VLSI Technology.
Advanced RISC Machines took over development of the ARM architecture and focused on licensing the technology to other companies. This business model proved highly successful and soon many major electronics firms were licensing ARM cores for use in their own custom chips and devices.
Apple & the Newton PDA
One of ARM’s first major customers was Apple. Apple licensed the ARM architecture in the early 1990s to develop a custom system-on-chip for its Newton personal digital assistant (PDA).
Introduced in 1993, the Newton featured an ARM 610 processor integrated with memory, I/O, and other system components on a single chip. This helped miniaturize the device while providing good performance for applications like handwriting recognition.
The Newton processor design validated ARM’s business model of licensing processor IP and highlighted the advantages of the ARM architecture for low-power embedded applications.
The ARM7 & ARM9 Families
In the mid-1990s, ARM transitioned to the ARM7 and ARM9 processor families. These provided higher performance along with features like on-chip cache, DSP extensions, and Jazelle technology for hardware acceleration of Java.
The ARM7TDMI variant became very popular in embedded systems and microcontrollers. It was widely used in devices like cell phones, MP3 players, routers, and hard disk drives. The ARM9 family extended ARM into higher-performance applications processors used in early PDAs and smartphones.
The Era of Low-Power Mobile Devices
By the early 2000s, ARM processors were being widely used by companies like Texas Instruments, Qualcomm, Samsung, and others to power the new generation of mobile phones, smartphones, and other portable devices. The combination of high performance and very low power consumption made ARM the dominant architecture in the mobile era.
Processor families like the ARM9 and ARM11were designed specifically for mobile applications. They incorporated features like dynamic voltage scaling, clock gating, and power-efficient pipelines to maximize battery life. ARM’s simplicity also made its cores easy to customize and integrate into low-power system-on-chip designs.
iPhone & the Smartphone Revolution
The release of the iPhone in 2007 marked a major inflection point for ARM. The iPhone used an ARM-based processor from Samsung, integrating the applications processor, graphics processing unit (GPU), and cellular modem on a single chip.
The iPhone proved the viability of ARM-based processors even for compute-intensive applications like web browsing, ushering in the smartphone revolution. The combination of high performance and low power consumption provided by ARM made it the ideal architecture for smartphones.
Advanced ARM Processor Cores
To address the increased performance demands of smartphones and mobile computing, ARM developed more advanced processor cores optimized for higher speeds. Important ARM releases included:
- Cortex-A8 – High-performance appications processor core
- Cortex-A9 – Dual and quad core appications processor
- Cortex-A15 – Higher clock speeds and performance optimizations
- Cortex-A50 – 64-bit core supporting the ARMv8 architecture
ARM also added technologies like NEON SIMD processing and hardware virtualization support to boost performance in mobile SoCs.
The Multicore Era
In the late 2000s, ARM began licensing multicore implementations of its cores to boost parallel processing performance. Important milestones included:
- ARM MPCore – Early symmetric dual core design
- ARM big.LITTLE – Heterogeneous cores for balancing performance and efficiency
- ARM Tri-Gate – Processor transistors for lower power and higher performance
ARM multicore processors enabled major performance gains in mobile devices while retaining power efficiency. This allowed smartphones and tablets to run ever more demanding applications and workloads.
Growth of ARM Ecosystem
A key factor in ARM’s success has been the ecosystem of third-party firms that design chips, software, and development tools around ARM architecture. Companies like Qualcomm, Samsung, Nvidia, Marvell, and many others now supply ARM-based processors and silicon.
Equally important has been software support for the ARM ecosystem. Operating systems like iOS, Android, Windows, and Linux all support ARM. There is also a large array of development tools, debuggers, emulators, and other software to support ARM processors.
ARM Today & the Future
Today, ARM remains the dominant player in mobile computing, with its processors featured in over 95% of smartphones. ARM is also making inroads into new markets like servers, networking infrastructure, and automotive. Over 100 billion ARM-based chips have been shipped to date.
Looking ahead, ARM is well positioned to capitalize on major technology trends like 5G, artificial intelligence, machine learning, computer vision, and edge computing. With its continued focus on power efficiency and performance innovations, expect ARM to continue leading the way into the future of computing.