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# PMEVCNTR<n>_EL0, Performance Monitors Event Count Registers, n = 0 - 30

The PMEVCNTR<n>_EL0 characteristics are:

## Purpose

Holds event counter n, which counts events, where n is 0 to 30.

## Configuration

AArch64 System register PMEVCNTR<n>_EL0 bits [31:0] are architecturally mapped to AArch32 System register PMEVCNTR<n>[31:0] .

AArch64 System register PMEVCNTR<n>_EL0 bits [31:0] are architecturally mapped to External register PMEVCNTR<n>_EL0[31:0] .

This register is in the Warm reset domain. On a Warm or Cold reset RW fields in this register reset to architecturally UNKNOWN values.

## Attributes

PMEVCNTR<n>_EL0 is a 64-bit register.

## Field descriptions

The PMEVCNTR<n>_EL0 bit assignments are:

### When ARMv8.5-PMU is implemented:

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
Event counter n
Event counter n
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

#### Bits [63:0]

Event counter n. Value of event counter n, where n is the number of this register and is a number from 0 to 30.

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

### Otherwise:

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
RES0
Event counter n
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

#### Bits [63:32]

Reserved, RES0.

#### Bits [31:0]

Event counter n. Value of event counter n, where n is the number of this register and is a number from 0 to 30.

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

## Accessing the PMEVCNTR<n>_EL0

PMEVCNTR<n>_EL0 can also be accessed by using PMXEVCNTR_EL0 with PMSELR_EL0.SEL set to the value of <n>.

If <n> is greater than or equal to the number of accessible counters, reads and writes of PMEVCNTR<n>_EL0 are CONSTRAINED UNPREDICTABLE, and the following behaviors are permitted:

- Accesses to the register are UNDEFINED.
- Accesses to the register behave as RAZ/WI.
- Accesses to the register execute as a NOP.
- If EL2 is implemented and enabled in the current Security state, and <n> is less than the number of implemented counters, accesses from EL1 or permitted accesses from EL0 are trapped to EL2.

Note

In EL0, an access is permitted if it is enabled by PMUSERENR_EL0.{ER,EN}.

If EL2 is implemented and enabled in the current Security state, in EL1 and EL0, MDCR_EL2.HPMN identifies the number of accessible counters. Otherwise, the number of accessible counters is the number of implemented counters. See MDCR_EL2.HPMN for more details.

Accesses to this register use the following encodings:

#### MRS <Xt>, PMEVCNTR<n>_EL0

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b011 | 0b1110 | 0b10[n:4:3] | 0b[n:2:0]

if PSTATE.EL == EL0 then if !ELUsingAArch32(EL1) && PMUSERENR_EL0.<ER,EN> == '00' then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)]; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)]; elsif PSTATE.EL == EL3 then return PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)];

#### MSR PMEVCNTR<n>_EL0, <Xt>

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b011 | 0b1110 | 0b10[n:4:3] | 0b[n:2:0]

if PSTATE.EL == EL0 then if !ELUsingAArch32(EL1) && PMUSERENR_EL0.EN == '0' then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)] = X[t]; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TPM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)] = X[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)] = X[t]; elsif PSTATE.EL == EL3 then PMEVCNTR_EL0[UInt(CRm<1:0>:op2<2:0>)] = X[t];

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

27/03/2019 21:59; e5e4db499bf9867a4b93324c4dbac985d3da9376

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