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SPMACCESSR_EL3

SPMACCESSR_EL3, System Performance Monitors Access Register (EL3)

The SPMACCESSR_EL3 characteristics are:

Purpose

Controls access to System PMUs from EL2, EL1 and EL0.

Configuration

This register is present only when FEAT_SPMU is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to SPMACCESSR_EL3 are UNDEFINED.

Attributes

SPMACCESSR_EL3 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
P31P30P29P28P27P26P25P24P23P22P21P20P19P18P17P16
P15P14P13P12P11P10P9P8P7P6P5P4P3P2P1P0

P<m>, bits [2m+1:2m], for m = 31 to 0

System PMU <m> access. Controls access to System PMU <m>.

P<m>Meaning
0b00

MRS read and MSR write System register accesses to System PMU <m> at EL2, EL1, and EL0 are trapped to EL3, unless the instruction generates a higher priority exception.

0b01

MSR write System register accesses to System PMU <m> at EL2, EL1, and EL0 are trapped to EL3, unless the instruction generates a higher priority exception.

0b11

This control does not cause any instructions to be trapped.

All other values are reserved.

The registers trapped by this control are:

AArch64: SPMCFGR_EL1, SPMCGCR<n>_EL1, SPMCNTENCLR_EL0, SPMCNTENSET_EL0, SPMCR_EL0, SPMDEVAFF_EL1, SPMDEVARCH_EL1, SPMEVCNTR<n>_EL0, SPMEVFILT2R<n>_EL0, SPMEVFILTR<n>_EL0, SPMEVTYPER<n>_EL0, SPMIIDR_EL1, SPMINTENCLR_EL1, SPMINTENSET_EL1, SPMOVSCLR_EL0, SPMOVSSET_EL0, and SPMSCR_EL1.

The reset behavior of this field is:

Accessing this field has the following behavior:

Accessing SPMACCESSR_EL3

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, SPMACCESSR_EL3

op0op1CRnCRmop2
0b100b1100b10010b11010b011

if !(IsFeatureImplemented(FEAT_SPMU) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then Undefined(); elsif PSTATE.EL == EL2 then Undefined(); elsif PSTATE.EL == EL3 then X{64}(t) = SPMACCESSR_EL3(); end;

MSR SPMACCESSR_EL3, <Xt>

op0op1CRnCRmop2
0b100b1100b10010b11010b011

if !(IsFeatureImplemented(FEAT_SPMU) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then Undefined(); elsif PSTATE.EL == EL2 then Undefined(); elsif PSTATE.EL == EL3 then SPMACCESSR_EL3() = X{64}(t); end;


2026-03-12 12:23:09, 2025-09_rel_asl1

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