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SPMZR_EL0

SPMZR_EL0, System Performance Monitors Zero with Mask

The SPMZR_EL0 characteristics are:

Purpose

Zero the set of System PMU event counters specified by the mask written to SPMZR_EL0.

Configuration

This register is present only when FEAT_SPMU2 is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to SPMZR_EL0 are UNDEFINED.

Attributes

SPMZR_EL0 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
P63P62P61P60P59P58P57P56P55P54P53P52P51P50P49P48P47P46P45P44P43P42P41P40P39P38P37P36P35P34P33P32
P31P30P29P28P27P26P25P24P23P22P21P20P19P18P17P16P15P14P13P12P11P10P9P8P7P6P5P4P3P2P1P0

P<m>, bit [m], for m = 63 to 0

Zero event counter <m>.

P<m>Meaning
0b0

Write is ignored.

0b1

Set event counter<m> in System PMU <s> to zero.

The reset behavior of this field is:

Accessing this field has the following behavior:

Accessing SPMZR_EL0

To access SPMZR_EL0 for System PMU <s>, set SPMSELR_EL0.SYSPMUSEL to s.

SPMZR_EL0 ignores writes if System PMU <s> is not implemented.

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

MSR SPMZR_EL0, <Xt>

op0op1CRnCRmop2
0b100b0110b10010b11000b100

if !(IsFeatureImplemented(FEAT_SPMU2) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3().EnPM2 == '0' then Undefined(); elsif HaveEL(EL3) && EL3SDDUndefPriority() && SPMACCESSR_EL3()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then Undefined(); elsif MDSCR_EL1().EnSPM == '0' then if EL2Enabled() && HCR_EL2().TGE == '1' then AArch64_SystemAccessTrap(EL2, 0x18); else AArch64_SystemAccessTrap(EL1, 0x18); end; elsif !ELIsInHost(EL0) && SPMACCESSR_EL1()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' 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().nSPMEVCNTRn_EL0 == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().EnSPM == '0' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && SPMACCESSR_EL2()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3().EnPM2 == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif HaveEL(EL3) && SPMACCESSR_EL3()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else SPMZR_EL0(UInt(SPMSELR_EL0().SYSPMUSEL)) = X{64}(t); end; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3().EnPM2 == '0' then Undefined(); elsif HaveEL(EL3) && EL3SDDUndefPriority() && SPMACCESSR_EL3()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3().FGTEn2 == '0') || HDFGWTR2_EL2().nSPMEVCNTRn_EL0 == '0') then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2().EnSPM == '0' then AArch64_SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && SPMACCESSR_EL2()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3().EnPM2 == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif HaveEL(EL3) && SPMACCESSR_EL3()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else SPMZR_EL0(UInt(SPMSELR_EL0().SYSPMUSEL)) = X{64}(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3().EnPM2 == '0' then Undefined(); elsif HaveEL(EL3) && EL3SDDUndefPriority() && SPMACCESSR_EL3()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then Undefined(); elsif HaveEL(EL3) && MDCR_EL3().EnPM2 == '0' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif HaveEL(EL3) && SPMACCESSR_EL3()[UInt(SPMSELR_EL0().SYSPMUSEL) * 2+:2] != '11' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else SPMZR_EL0(UInt(SPMSELR_EL0().SYSPMUSEL)) = X{64}(t); end; elsif PSTATE.EL == EL3 then SPMZR_EL0(UInt(SPMSELR_EL0().SYSPMUSEL)) = X{64}(t); end;


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

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