This guide introduces the main features of Advanced Microcontroller Bus Architecture (AMBA) AXI4, highlighting the differences from the previous version AXI3. The guide explains the key concepts and details that help you implement the AXI4 protocol.

In this guide, we describe:

  • What AMBA is.
  • Why AMBA is so popular in modern SoC design.
  • The concepts of transfers and transactions, which underpin how AMBA operates.
  • The different channel signals and the functionality that they provide.
  • Exclusive access transfers, which allow multiple requesters to access the same completer at the same time.
  • The rules and conditions that the AMBA protocol dictates.
  • The key attributes and support for common elements like mixed endian structures.

At the end of this guide, you can Check your knowledge.

Note: Diversity and inclusion are important values to Arm. Because of this, we are re-evaluating the terminology we use in our technical documentation. Older Arm documentation, including the AMBA AXI and ACE protocol specification, uses the terms master and slave. This guide uses replacement terminology, as follows:

  • The new term requester is synonymous with master in older documentation.
  • The new term completer is synonymous with slave in older documentation.