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PMCNTENCLR_EL0, Performance Monitors Count Enable Clear register

The PMCNTENCLR_EL0 characteristics are:

Purpose

Disables the Cycle Count Register, PMCCNTR_EL0, and any implemented event counters PMEVCNTR<n>. Reading this register shows which counters are enabled.

Configuration

AArch64 System register PMCNTENCLR_EL0 bits [31:0] are architecturally mapped to AArch32 System register PMCNTENCLR[31:0] .

AArch64 System register PMCNTENCLR_EL0 bits [31:0] are architecturally mapped to External register PMCNTENCLR_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

PMCNTENCLR_EL0 is a 64-bit register.

Field descriptions

The PMCNTENCLR_EL0 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
00000000000000000000000000000000
CP<n>, bit [n]
313029282726252423222120191817161514131211109876543210

Bits [63:32]

Reserved, RES0.

C, bit [31]

PMCCNTR_EL0 disable bit. Disables the cycle counter register. Possible values are:

CMeaning
0b0

When read, means the cycle counter is disabled. When written, has no effect.

0b1

When read, means the cycle counter is enabled. When written, disables the cycle counter.

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

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

Event counter disable bit for PMEVCNTR<n>_EL0.

If N is less than 31, then bits [30:N] are RAZ/WI. When EL2 is implemented and enabled in the current Security state, in EL1 and EL0, N is the value in MDCR_EL2.HPMN. Otherwise, N is the value in PMCR_EL0.N.

P<n>Meaning
0b0

When read, means that PMEVCNTR<n>_EL0 is disabled. When written, has no effect.

0b1

When read, means that PMEVCNTR<n>_EL0 is enabled. When written, disables PMEVCNTR<n>_EL0.

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

Accessing the PMCNTENCLR_EL0

Accesses to this register use the following encodings:

MRS <Xt>, PMCNTENCLR_EL0

op0CRnop1op2CRm
0b110b10010b0110b0100b1100
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
        return PMCNTENCLR_EL0;
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 PMCNTENCLR_EL0;
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    else
        return PMCNTENCLR_EL0;
elsif PSTATE.EL == EL3 then
    return PMCNTENCLR_EL0;
              

MSR PMCNTENCLR_EL0, <Xt>

op0CRnop1op2CRm
0b110b10010b0110b0100b1100
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
        PMCNTENCLR_EL0 = 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
        PMCNTENCLR_EL0 = X[t];
elsif PSTATE.EL == EL2 then
    if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TPM == '1' then
        AArch64.SystemAccessTrap(EL3, 0x18);
    else
        PMCNTENCLR_EL0 = X[t];
elsif PSTATE.EL == EL3 then
    PMCNTENCLR_EL0 = X[t];
              


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