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PMEVCNTSVR<n>_EL1: Performance Monitors Event Count Saved Value Register <n>, n = 0 - 30

Purpose

Captures the PMU Event counter <n>, PMEVCNTR<n>_EL0.

Configuration

AArch64 System register PMEVCNTSVR<n>_EL1 bits [63:0] are architecturally mapped to External register PMU.PMEVCNTSVR<n>_EL1[63:0].

This register is present only when FEAT_PMUv3_SS is implemented. Otherwise, direct accesses to PMEVCNTSVR<n>_EL1 are UNDEFINED.

Attributes

PMEVCNTSVR<n>_EL1 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
EVCNT
EVCNT

EVCNT, bits [63:0]

Sampled Event Count. The value of PMEVCNTR<n>_EL0 at the last successful Capture event.

The reset behavior of this field is:

Accessing PMEVCNTSVR<n>_EL1

If <n> is greater-than-or-equal-to the number of implemented event counters, then direct reads of PMEVCNTSVR<n>_EL1 are UNDEFINED.

Otherwise, direct reads of PMEVCNTSVR<n>_EL1 generate a Trap exception to EL2 when all of the following are true:

Note

If EL2 is implemented and enabled in the current Security state, MDCR_EL2.HPMN identifies the number of accessible snapshot registers at EL1. Otherwise, the number of accessible snapshot registers is the number of implemented event counters. See MDCR_EL2.HPMN for more details.

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

MRS <Xt>, PMEVCNTSVR<m>_EL1 ; Where m = 0-30

op0op1CRnCRmop2
0b100b0000b11100b10:m[4:3]m[2:0]

integer m = UInt(CRm<1:0>:op2<2:0>); if m >= NUM_PMU_COUNTERS then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.EnPMSS == '0' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT2) && ((HaveEL(EL3) && SCR_EL3.FGTEn2 == '0') || HDFGRTR2_EL2.nPMSSDATA == '0') then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && m >= GetNumEventCountersAccessible() then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.EnPMSS == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = PMEVCNTSVR_EL1[m]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.EnPMSS == '0' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.EnPMSS == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = PMEVCNTSVR_EL1[m]; elsif PSTATE.EL == EL3 then X[t, 64] = PMEVCNTSVR_EL1[m];