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).

PMCNTENSET_EL0

PMCNTENSET_EL0, Performance Monitors Count Enable Set Register

The PMCNTENSET_EL0 characteristics are:

Purpose

Allows software to enable the following counters:

Reading from this register shows which counters are enabled.

Configuration

External register PMCNTENSET_EL0 bits [31:0] are architecturally mapped to AArch64 System register PMCNTENSET_EL0[31:0] when FEAT_PMUv3_EXT32 is implemented, FEAT_PMUv3p9 is not implemented, and FEAT_PMUv3_ICNTR is not implemented.

External register PMCNTENSET_EL0 bits [31:0] are architecturally mapped to AArch64 System register PMCNTENCLR_EL0[31:0] when FEAT_PMUv3_EXT32 is implemented, FEAT_PMUv3p9 is not implemented, and FEAT_PMUv3_ICNTR is not implemented.

External register PMCNTENSET_EL0 bits [63:0] are architecturally mapped to AArch64 System register PMCNTENSET_EL0[63:0] when FEAT_PMUv3_EXT64 is implemented or FEAT_PMUv3p9 is implemented.

External register PMCNTENSET_EL0 bits [63:0] are architecturally mapped to AArch64 System register PMCNTENCLR_EL0[63:0] when FEAT_PMUv3_EXT64 is implemented or FEAT_PMUv3p9 is implemented.

External register PMCNTENSET_EL0 bits [31:0] are architecturally mapped to AArch32 System register PMCNTENCLR[31:0].

External register PMCNTENSET_EL0 bits [31:0] are architecturally mapped to AArch32 System register PMCNTENSET[31:0].

This register is present only when FEAT_PMUv3_EXT is implemented and FEAT_PMUv3 is implemented. Otherwise, direct accesses to PMCNTENSET_EL0 are RES0.

PMCNTENSET_EL0 is in the Core power domain.

Attributes

PMCNTENSET_EL0 is a:

This register is part of the PMU block.

Field descriptions

When FEAT_PMUv3_EXT64 is implemented, or FEAT_PMUv3p9 is implemented, or FEAT_PMUv3_ICNTR is implemented:

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0F0
CP30P29P28P27P26P25P24P23P22P21P20P19P18P17P16P15P14P13P12P11P10P9P8P7P6P5P4P3P2P1P0

Bits [63:33]

Reserved, RES0.

F0, bit [32]
When FEAT_PMUv3_ICNTR is implemented:

PMICNTR_EL0 enable. On writes, allows software to enable PMICNTR_EL0. On reads, returns the PMICNTR_EL0 enable status.

F0Meaning
0b0

PMICNTR_EL0 disabled.

0b1

PMICNTR_EL0 enabled.

The reset behavior of this field is:

Accessing this field has the following behavior:


Otherwise:

Reserved, RES0.

C, bit [31]

PMCCNTR_EL0 enable. On writes, allows software to enable PMCCNTR_EL0. On reads, returns the PMCCNTR_EL0 enable status.

CMeaning
0b0

PMCCNTR_EL0 disabled.

0b1

PMCCNTR_EL0 enabled.

The reset behavior of this field is:

Accessing this field has the following behavior:

P<m>, bit [m], for m = 30 to 0

PMEVCNTR<m>_EL0 enable. On writes, allows software to enable PMEVCNTR<m>_EL0. On reads, returns the PMEVCNTR<m>_EL0 enable status.

P<m>Meaning
0b0

PMEVCNTR<m>_EL0 disabled.

0b1

PMEVCNTR<m>_EL0 enabled.

The reset behavior of this field is:

Accessing this field has the following behavior:

Otherwise:

313029282726252423222120191817161514131211109876543210
CP30P29P28P27P26P25P24P23P22P21P20P19P18P17P16P15P14P13P12P11P10P9P8P7P6P5P4P3P2P1P0

C, bit [31]

PMCCNTR_EL0 enable. On writes, allows software to enable PMCCNTR_EL0. On reads, returns the PMCCNTR_EL0 enable status.

CMeaning
0b0

PMCCNTR_EL0 disabled.

0b1

PMCCNTR_EL0 enabled.

The reset behavior of this field is:

Accessing this field has the following behavior:

P<m>, bit [m], for m = 30 to 0

PMEVCNTR<m>_EL0 enable. On writes, allows software to enable PMEVCNTR<m>_EL0. On reads, returns the PMEVCNTR<m>_EL0 enable status.

P<m>Meaning
0b0

PMEVCNTR<m>_EL0 disabled.

0b1

PMEVCNTR<m>_EL0 enabled.

The reset behavior of this field is:

Accessing this field has the following behavior:

Accessing PMCNTENSET_EL0

Accesses to this register use the following encodings:

When FEAT_PMUv3_EXT64 is implemented, or FEAT_PMUv3_ICNTR is implemented, or FEAT_PMUv3p9 is implemented

[63:0] Accessible at offset 0xC00 from PMU

When FEAT_PMUv3_EXT32 is implemented, FEAT_PMUv3_ICNTR is not implemented, and FEAT_PMUv3p9 is not implemented

[31:0] Accessible at offset 0xC00 from PMU


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

Copyright © 2010-2026 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.