Everything about ARM

ARM (stylised in lowercase as arm, previously an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of reduced instruction set computing (RISC) architectures for computer processors, configured for various environments.

Summary

  • ARM is the leading technology provider of processor IP, offering the widest range of processors to address the performance, power, and cost requirements of every device. Arm CPUs and NPUs include Cortex-A, Cortex-M, Cortex-R, Neoverse, Ethos and SecurCore.
  • ARM licenses their IP to Apple, Microsoft, Quacomm etc… which means the companies pays ARM the company to use it’s patents and designs for their CPUs and chips
  • ARM can be licensed to multiple companies to develop custom chips (from tablets, phones, smart tvs, smart speakers etc…)

ARM vs x86

  • x86 is a family of instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor
  • Both are ways to delivery instructions at the lowest level to the chipset
  • ARM requires a much smaller instruction set than x86
  • ARM gives instructions one at a time vs x86 gives a full list and lets the processor parse out the instructions and process it
  • x86 has the advantage where it can handle more complex instructions and can find the best way to manage all tasks all at once
  • ARM is a lot more power efficient + less heat produced
  • ARM is found in all mobile phones vs x86 are mostly personal computers, workstations servers and super computers.

Limitations Today

  • Most computer software today is built using x86 architecture. Microsoft/Apple built custom code to make x86 software compatitible with ARM, but the conversion isn’t perfect (buggy, glitchy and slow)