System Register XML
for Armv9
(2021-09)

30 September 2021


1. Introduction

This is the 2021-09 release of the System Registers XML for Armv9 A-profile architecture.

The Proprietary Notice gives details of the terms and conditions under which this package is provided.

If you have comments on the content of this package, please send them by e-mail to support-aarchv8@arm.com. Give:

Please see the Documentation for more information on the general structure of these descriptions.


2. Contents

This Version 2021-09 [HTML] [PDF] [XML]
Change Markups
2021-09 from 2021-06
[HTML] [PDF]
Previous Versions
2021-06
[HTML]


3. Release notes

Armv9 change history

Armv9 known issues

Armv8.8 change history

Arm v8.8 known issues

Potential upcoming changes

Arm is constantly exploring ways to make the architecture presentation precise and clear. Towards this, the following changes are expected in future releases (2021-12, 2022-03, 2022-06):

In addition, we are looking in improvements to the information that is provided in the XML. In some cases these changes may impact users. Here is a list of areas where we may make change in a future release:


4. Documentation

General

A description within the XML contains the following sections:

Purpose
A short description of the purpose of the register in the Armv8 Architecture.
Configuration
How the register is architecturally mapped onto another System register or a memory-mapped register. If the configuration of the PE affects the implementation of the register, then information about this is also included here.
Attributes
The size of the register.
Field descriptions
The register diagram and a description of the behavior of each field within the register.

Memory-mapped registers

A memory-mapped register description also contains the following sections:

Accessing ...
The address or offset of the register in the memory map, and the accessibility.

System registers

A System register description also contains an "Accessing ..." section, that includes: