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ARM Compiler Version 5

Learning Platform

The ARM Compiler is specifically designed to optimize software running on ARM processors. It is the result of 20 years of development alongside the ARM Architecture. The ARM Compiler toolchain incorporates a highly optimizing C/C++ compiler, assembler, linker and libraries for embedded software development.

Billions of devices containing software built with ARM tools have shipped to date, covering all embedded markets. Whether your industry is avionics, consumer electronics, mobile, industrial automation, automotive or medical, the ARM compiler can play a key role in optimizing your code.

Superior Performance

The highly efficient ARM Compiler invokes powerful optimization techniques such as loop unrolling, function inlining, idiom recognition, and architecture-specific instruction scheduling.

Superior Code Size Reduction


The ARM Compiler has a long embedded heritage, where memory space is a prized commodity. It incorporates techniques that can reduce your application footprint by up to 30% compared to other compilers. The ARM Compiler reduces the best code size by up to 5% compared to the RVDS 4.0 compiler.

In addition, the ARM Compiler includes an optional MicroLib C library for Cortex-M series microcontrollers, which provides up to a 50% reduction in code size compared to the full standard C library.

The MicroLib C library provides a completely C-based development environment without the need to revert to assembly language - even for interrupt service routines. This removes the need for specific knowledge of the ARM architecture.

Superior Value

Whether you are creating a modern application targeting a Cortex-M7 microcontroller or or rebuilding a 10-year-old library targeting the ARM7TDMI®, you only need a single license. An MDK-ARM license works with older compiler versions, making modifications to legacy code easy.


The ARM Compiler features full support for C90, C99 and C++2003 with optimized routines for ARM and Thumb-2 which can greatly improve the performance of your code.

TÜV Certification, Compiler Qualification Kit & Extended Maintenance

TUV Certification

The ARM Compiler toolchain is certified by TÜV SÜD, a recognized safety industry expert. The TÜV Certificate and the accompanying report confirm that the ARM Compiler 5.04 fulfills the requirements for development tools classified T3 according to IEC 61508-3. This enables customers to apply the ARM Compiler 5.04 for safety-related development up to SIL3 (IEC 61508) or ASILD (ISO 26262) without further qualification activities when following the recommendations and conditions documented in the Qualification Kit.

The ARM Compiler Qualification Kit consists of a significant body of supporting evidence derived from our development process including defect reports, C90/C99 test reports and a compiler safety manual, so that you can increase your confidence in providing a justification argument for compliance.

Learn more about Keil MDK for Functional Safety Applications »

To complement this, we also provide Extended Maintenance and Support to protect your safety-critical projects against toolchain obsolescence. Initially supported in ARM Compiler v5.04, Extended Maintenance and Support is intended to maximize the stability of a fixed branch of the compiler toolchain by providing bug fixes and patches for a minimum of 5 years.

Learn more about the ARM Compiler Extended Maintenance & Support »

The ARM Compiler Qualification Kit with Extended Maintenance is part of MDK-Professional.

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