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PMZR_EL0

PMZR_EL0, Performance Monitors Zero with Mask

The PMZR_EL0 characteristics are:

Purpose

Zero the set of counters specified by the mask written to PMZR_EL0.

Configuration

AArch64 System register PMZR_EL0 bits [63:0] are architecturally mapped to External register PMZR_EL0[63:0] when FEAT_PMUv3_EXT is implemented and FEAT_PMUv3p9 is implemented.

This register is present only when FEAT_PMUv3p9 is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to PMZR_EL0 are UNDEFINED.

Attributes

PMZR_EL0 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0F0
CP30P29P28P27P26P25P24P23P22P21P20P19P18P17P16P15P14P13P12P11P10P9P8P7P6P5P4P3P2P1P0

Bits [63:33]

Reserved, RES0.

F0, bit [32]
When FEAT_PMUv3_ICNTR is implemented:

Zero PMICNTR_EL0.

F0Meaning
0b0

Write is ignored.

0b1

Set PMICNTR_EL0 to zero.

Accessing this field has the following behavior:


Otherwise:

Reserved, RES0.

C, bit [31]

Zero PMCCNTR_EL0.

CMeaning
0b0

Write is ignored.

0b1

Set PMCCNTR_EL0 to zero.

Accessing this field has the following behavior:

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

Zero PMEVCNTR<m>_EL0.

P<m>Meaning
0b0

Write is ignored.

0b1

Set PMEVCNTR<m>_EL0 to zero.

Accessing this field has the following behavior:

Accessing PMZR_EL0

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

MSR PMZR_EL0, <Xt>

op0op1CRnCRmop2
0b110b0110b10010b11010b100

if !(IsFeatureImplemented(FEAT_PMUv3p9) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3().TPM == '1' then Undefined(); elsif PMUSERENR_EL0().EN == '0' && (!IsFeatureImplemented(FEAT_PMUv3p9) || PMUSERENR_EL0().UEN == '0') then if EL2Enabled() && HCR_EL2().TGE == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else AArch64_SystemAccessTrap(EL1, 0x18); end; elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3().FGTEn2 == '0') || HDFGWTR2_EL2().nPMZR_EL0 == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().TPM == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else ZeroPMUCounters(X{64}(t)); end; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3().TPM == '1' then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3().FGTEn2 == '0') || HDFGWTR2_EL2().nPMZR_EL0 == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().TPM == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else ZeroPMUCounters(X{64}(t)); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3().TPM == '1' then Undefined(); elsif HaveEL(EL3) && MDCR_EL3().TPM == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else ZeroPMUCounters(X{64}(t)); end; elsif PSTATE.EL == EL3 then ZeroPMUCounters(X{64}(t)); end;


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

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