This is a collection of Intel®’ IA32® Software Developer's Manuals (URL of the day) and AMD' AMD64 Architecture Programmer's Manual together with the related specifications, application notes, white papers, and change logs. The collection aims to keep all available revisions. It was originally created by Michal Necasek, see OS/2 Museum.

If you have a public document, related to the IA32® specifications and missing from the collection, please mail it to me. The content of this URL and all sub-ULRs is available for convenient bulk download by rsync x86docs password "" (empty).

GITS_MPAMIDR

GITS_MPAMIDR, Report maximum PARTID and PMG Register

The GITS_MPAMIDR characteristics are:

Purpose

Reports the maximum support PARTID and PMG values.

Configuration

This register is present only when GICv3.1 is implemented. Otherwise, direct accesses to GITS_MPAMIDR are RES0.

A copy of this register is provided for each ITS.

When GITS_TYPER.MPAM==0, this register is RES0.

Attributes

GITS_MPAMIDR is a 32-bit register.

Field descriptions

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
RES0								PMGmax								PARTIDmax

Bits [31:24]

Reserved, RES0.

PMGmax, bits [23:16]

Maximum PMG value supported.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

PARTIDmax, bits [15:0]

Maximum PARTID value supported.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Accessing GITS_MPAMIDR

GITS_MPAMIDR can be accessed through the memory-mapped interfaces:

Component	Offset
GIC ITS control	0x0010

Accesses to this register are RO.

2026-03-26 20:27:25, 2026-03_rel