ARM (Advanced RISC Machines) is a set of RISC instruction set architectures for computer processors, developed by Arm Ltd. It’s widely used due to its affordability, energy efficiency, and suitability for portable devices like smartphones, laptops, and other embedded systems.

ARM processors aren’t just for portable devices; they’re also used in desktops and servers, with Fugaku, the world’s fastest supercomputer from 2020 to 2022, powered by ARM processors. The first ARM processor released in 1990 was a collaborative effort by Acorn and Apple computer.

ARM uses RISC (Reduced Instruction Set Computer) computer architectuere that was first developed by Acorn in 1985. RISC architecture is designed to simplify the instructions that are given to the computer. Compared to CISC (Complex Instruction Set Computer), which requires less albiet instructions for a processor to perform a certain task and thus less code, while RISC architecture requires more simple instructions to perform the same task, thus requiring more code. ARM works by executing a single instructions per clock cycle, engaging less transistors from the hardware than complex instructions.

Features of ARM processors:

  • Multiprocessing System: A multiprocessing system utilizes multiple processors to execute tasks simultaneously, boosting overall system performance.
  • Tightly Coupled Memory: Tightly coupled memory refers to a configuration where processors share access to a common memory space, enabling fast communication and data sharing between them.
  • Memory Management: Memory management involves organizing and optimizing the allocation, usage, and deallocation of memory resources within a computer system to ensure efficient operation and prevent memory-related issues.
  • Thumb-2 Technology: Thumb-2 technology is a feature commonly found in ARM processors that enhances code density and performance by providing a mix of 16-bit and 32-bit instructions.
  • One-Cycle Execution Time: Achieving one-cycle execution time means completing the execution of an instruction within a single clock cycle, maximizing processor throughput and efficiency.
  • Pipelining: Pipelining is a technique used in processor design to overlap the execution of multiple instructions, improving throughput and overall performance by allowing multiple instructions to be in different stages of execution simultaneously.
  • A Large Number of Registers: Having a large number of registers in a processor enables efficient execution of instructions by providing ample storage for intermediate values and reducing the need for frequent memory access, thus enhancing performance.


In conclusion, ARM processors are extremely energy efficient and suitable processors for a variety of computer devices. These processors are not capable of high performance. These processors also need highly skilled programmers because execution is very important for them since the entire performance of the processor depends on the execution. There are a lot of compatibility issues with these processors because some software may not be compatible with them.