Additions to the Arm architecture are provided as version increments known as extensions. Extensions allow us to release new features regularly in response to the needs of our partners without making major changes to the main architecture.

We release a new extension every year. In line with this, our Cortex CPUs, which are our implementations of the architecture, utilize the latest extension depending on when they are released.

This guide explains extensions to the Arm architecture and provides guidance on how to read and use them. 

At the end of this guide, you can check your knowledge. You will have learned how the extensions are expressed, which features are available in which extensions, and how to determine which features of extension an Arm Cortex CPU implementation supports.