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Redirected from: Acorn RISC Machine

Definition: ARM


The most widely used microprocessors worldwide. Designed by ARM Holdings plc, Cambridge, England, the company was founded in 1990 by Acorn Computers, Apple and VLSI Technology. The ARM brand originally stood for Acorn RISC Machine and later Advanced RISC Machine.

In 2016, ARM was acquired by Japan-based Softbank, which agreed to sell the company to NVIDIA in 2020 for $40 billion, pending U.S. and U.K. approval. By 2022, the deal fell through.

Low Power Requirements
ARM chips are 32-bit and 64-bit RISC-based CPUs that are known for their low cost but primarily for their low power requirements (see RISC). In some cases, an ARM-based smartphone using five watts of battery can perform as well or better than a CISC-based desktop computer requiring more than 100 watts (see CISC).

Billions of ARM Chips Every Year
Manufactured under license from ARM by more than a dozen semiconductor companies, billions of ARM-based devices are made every year, including smartphones, tablets, e-book readers, TVs and myriad other consumer and industrial products. Apple surprised the industry in 2020 by using its new ARM-based chip in its laptop and desktop computers (see Apple M series).

Very often, multiple ARM processing cores make up the CPU in a system-on-chip (see SoC). For example, Qualcomm's Snapdragon and NVIDIA's Tegra are ARM-based smartphone and tablet SoCs. See Snapdragon and Tegra.

Cortex, SecurCore and StrongARM
ARM processor families are designated by the prefix "ARM" and a digit, such as ARM7, ARM9 and ARM11 or with names such as Cortex and SecurCore, the latter used for secure identification products such as smart cards.

The StrongARM was a high-speed version of the ARM chip that was jointly developed with Digital Equipment Corporation. The SA-100, the first StrongARM chip, was delivered in 1995, and Intel acquired the technology from Digital in 1997. See Intel Mac, Apple M series, StrongARM, Thumb and big.LITTLE.