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# PMSELR_EL0, Performance Monitors Event Counter Selection Register

The PMSELR_EL0 characteristics are:

## Purpose

Selects the current event counter PMEVCNTR<n>_EL1 or the cycle counter PMCCNTR.

Used in conjunction with PMXEVTYPER_EL0 to determine the event that increments a selected counter, and the modes and states in which the selected counter increments.

Used in conjunction with PMXEVCNTR_EL0 to determine the value of a selected counter.

## Configuration

AArch64 System register PMSELR_EL0 bits [31:0] are architecturally mapped to AArch32 System register PMSELR[31:0].

This register is present only when FEAT_PMUv3 is implemented. Otherwise, direct accesses to PMSELR_EL0 are UNDEFINED.

## Attributes

PMSELR_EL0 is a 64-bit register.

## Field descriptions

63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
RES0
RES0 | SEL

#### Bits [63:5]

Reserved, RES0.

#### SEL, bits [4:0]

Event counter select. Selects the counter accessed by subsequent accesses to PMXEVTYPER_EL0 and PMXEVCNTR_EL0.

SEL | Meaning
--- | ---
0b00000..0b11110 | Select event counter PMEVCNTR<n>_EL0, where n is the value of this field: MRS and MSR of PMXEVTYPER_EL0 access PMEVTYPER<n>_EL0. MRS and MSR of PMXEVCNTR_EL0 access PMEVCNTR<n>_EL0.
0b11111 | Select the cycle counter, PMCCNTR_EL0: MRS and MSR of PMXEVTYPER_EL0 access PMCCFILTR_EL0. MRS and MSR of PMXEVCNTR_EL0 are CONSTRAINED UNPREDICTABLE. For more information, see PMXEVCNTR_EL0.

If FEAT_FGT is not implemented and this field is set to a value greater than or equal to the number of implemented counters, but not equal to 31, then direct reads of this field return an UNKNOWN value.

For more information about the results of accesses to the event counters, including when PMSELR_EL0.SEL is set to the index of an unimplemented or inaccessible event counter, see PMXEVTYPER_EL0 and PMXEVCNTR_EL0.

The reset behavior of this field is:

- On a Warm reset, this field resets to an architecturally UNKNOWN value.

## Accessing PMSELR_EL0

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

#### MRS <Xt>, PMSELR_EL0

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b011 | 0b1001 | 0b1100 | 0b101

if PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TPM == '1' then UNDEFINED; elsif (IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0.<UEN,ER,EN> == '000') || (!IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0.<ER,EN> == '00') then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGRTR_EL2.PMSELR_EL0 == '1' 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); else X[t, 64] = PMSELR_EL0; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TPM == '1' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGRTR_EL2.PMSELR_EL0 == '1' 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); else X[t, 64] = PMSELR_EL0; 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); else X[t, 64] = PMSELR_EL0; elsif PSTATE.EL == EL3 then X[t, 64] = PMSELR_EL0;

#### MSR PMSELR_EL0, <Xt>

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b011 | 0b1001 | 0b1100 | 0b101

if PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TPM == '1' then UNDEFINED; elsif (IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0.<UEN,ER,EN> == '000') || (!IsFeatureImplemented(FEAT_PMUv3p9) && PMUSERENR_EL0.<ER,EN> == '00') then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.PMSELR_EL0 == '1' 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); else PMSELR_EL0 = X[t, 64]; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TPM == '1' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.PMSELR_EL0 == '1' 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); else PMSELR_EL0 = X[t, 64]; 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); else PMSELR_EL0 = X[t, 64]; elsif PSTATE.EL == EL3 then PMSELR_EL0 = X[t, 64];

AArch32 Registers | AArch64 Registers | AArch32 Instructions | AArch64 Instructions | Index by Encoding | External Registers | External Registers by Offset | Registers by Functional Group | Proprietary Notice

26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6

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