Disambiguation: ARM Architecture

ARM architecture

is a computer instruction set architecture developed by ARM Holdings.

ARM = Advanced RISC Machine
RISC = Reduced Instruction Set Computer

An instruction set is a list of all the instructions that a processor can execute (e.g. add, subtract, move, load, store, etc.).


In 2005, about 98 percent of the more than one billion mobile phones sold each year used at least one ARM processor. ARM processors are used extensively in consumer electronics, including PDAs, mobile phones, digital media and music players, hand-held game consoles, calculators and computer peripherals such as hard drives and routers. [thanks dailymonivore]


Beginnings: In the 1980s, Acorn Computers Ltd. had some success with their BBC Micro shown here

OLYMPUS DIGITAL CAMERA and wanted to make something better than the CMOS processor it used.

CMOS = Complementary Metal-Oxide Semiconductor

The evolution of CMOS technology is commonly described by Moore’s Law. In 1963 Gordon Moore predicted that as a result of continuous miniaturization, transistor count would double every 18 months. The observation made by Gordon Moore was that the number of components on the most complex integrated circuit chip would double each year for the next 10 years. This doubling was based on a 50 – 60-component chip produced at that point of time compared with those produced in preceding years. Looks surprising, but his prediction has turned true and is being treated as a law.  The speed of transistors increases and their cost decreases as their size is reduced. The transistors manufactured today are 20 times faster and occupy less than 1% of the area of those built 20-30 years ago. [thanks engineersgarage]


for Acorn Computers, processors such as the Motorola 68000 were not powerful enough to handle graphics and GUIs, so Steve Furber and Sophie Wilson of Acorn Ltd. set out to make their own processors.

 GUI = Graphical User Interface


Sophie developed the instruction set and simulated it on the BBC Basic which convinced many in the company that it was not just anything half hearted shot aimed in darkness. With the support and permission of the then CEO Hermann Hauser, the ARM project formally took off in 1983 with VLSI Technology as their silicon partner, to produce an ARM processor with latencies as low as that of the 6502.

Technical note: In computers, latency is the delay between your computer sending the instruction to do something, and the processor actually doing it. (A processor with a high latency makes a computer very annoying computer to use.)

The first ARM core was the ARM1 delivered by VLSI Technology in 1985. This processor used in conjunction with the BBC Micro helped in the development of the next generation called ARM2. 1987 saw the release of ARM Archimedes.

Acorn created a new company Advanced RISC Machines Ltd. solely dedicated for ARM core development. In 1992, Acorn won the Queen’s Award for Technology for the ARM. Apple and ARM collaborated to develop the ARM6 cores on which the Apple Newton PDAs were based. Later, the technology was also transferred to Intel over a settlement of lawsuit. Intel further modified it and developed its own high performance line XScale, now sold to Marvell. ARM Inc. is involved with developing cores primarily while its licensees make microcontroller and processors, the most popular being the ARM7TDMI machines. Some prominent licensees of ARM machines are Alcatel Lucent, Apple, Atmel, Cirrus Logic, Freescale, DEC, Intel, LG, Marvell, Microsoft, Nvidia, Qualcomm, Samsung, Sharp, ST microelectronics, Symbios Logic, Texas Instruments, VLSI Technology, Yamaha, Zilabs etc. [thanks engineers garage]

Licensed worldwide, the ARM architecture is the most commonly implemented 32-bit instruction set architecture. ARM architecture is implemented on Windows, Unix, and Unix-like operating systems, including Apple iOS, Android, BSD, Inferno, Solaris, WebOS, Plan 9 and GNU/Linux. [thanks technopedia]

In short, ARM architecture is fairly useful stuff. If it’s a computer or a mobile phone, it probably does what it does because of ARM architecture. ARM architecture is not trying to be beautiful.

Do not confuse with the buildings designed by architects, ARM Architecture. Here’s their recently-completed Perth Arena. [thanks for the pic, wikipeeps]