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# PMOVSCLR_EL0, Performance Monitors Overflow Flag Status Clear Register

The PMOVSCLR_EL0 characteristics are:

## Purpose

Allows software to clear the unsigned overflow flags for the following counters to 0:

- The cycle counter PMCCNTR_EL0.
- The event counters PMEVCNTR<n>_EL0.
- When FEAT_PMUv3_ICNTR is implemented, the instruction counter PMICNTR_EL0.

Reading from this register shows the current unsigned overflow flag values.

## Configuration

AArch64 System register PMOVSCLR_EL0 bits [31:0] are architecturally mapped to AArch32 System register PMOVSR[31:0].

AArch64 System register PMOVSCLR_EL0 bits [31:0] are architecturally mapped to AArch32 System register PMOVSSET[31:0].

AArch64 System register PMOVSCLR_EL0 bits [31:0] are architecturally mapped to External register PMU.PMOVSCLR_EL0[31:0].

AArch64 System register PMOVSCLR_EL0 bits [31:0] are architecturally mapped to External register PMU.PMOVSSET_EL0[31:0].

AArch64 System register PMOVSCLR_EL0 bits [63:32] are architecturally mapped to External register PMU.PMOVSCLR_EL0[63:32] when FEAT_PMUv3p9 is implemented or FEAT_PMUv3_EXT64 is implemented.

AArch64 System register PMOVSCLR_EL0 bits [63:32] are architecturally mapped to External register PMU.PMOVSSET_EL0[63:32] when FEAT_PMUv3p9 is implemented or FEAT_PMUv3_EXT64 is implemented.

AArch64 System register PMOVSCLR_EL0 bits [63:0] are architecturally mapped to External register PMU.PMOVS[63:0].

This register is present only when FEAT_PMUv3 is implemented. Otherwise, direct accesses to PMOVSCLR_EL0 are UNDEFINED.

## Attributes

PMOVSCLR_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 | F0
C | P30 | P29 | P28 | P27 | P26 | P25 | P24 | P23 | P22 | P21 | P20 | P19 | P18 | P17 | P16 | P15 | P14 | P13 | P12 | P11 | P10 | P9 | P8 | P7 | P6 | P5 | P4 | P3 | P2 | P1 | P0

#### Bits [63:33]

Reserved, RES0.

#### F<m>, bit [m+32], for m = 0
When FEAT_PMUv3_ICNTR is implemented:

Unsigned overflow flag for fixed-function counter <m> clear. On writes, allows software to clear the unsigned overflow flag for fixed-function counter <m> to 0. On reads, returns the unsigned overflow flag for fixed-function counter <m> overflow status.

F<m> | Meaning
--- | ---
0b0 | Fixed-function counter <m> has not overflowed.
0b1 | Fixed-function counter <m> has overflowed.

PMOVSCLR_EL0.F0 holds the overflow status for PMICNTR_EL0.

Accessing this field has the following behavior:

- This field reads-as-zero if all of the following are true:
  - Any of the following are true:
    - EL3 is implemented and SCR_EL3.FGTEn2 == 0.
    - HDFGRTR2_EL2.nPMICFILTR_EL0 == 0.
  - FEAT_FGT2 is implemented.
  - EL2 is implemented and enabled in the current Security state.
  - Accessed at EL1 or EL0.
  - The Effective value of HCR_EL2.{E2H, TGE} is not {1, 1}.
- Permitted reads and writes of this field are RAZ/WI if any of the following are true:
  - All of the following are true:
    - EL3 is implemented.
    - MDCR_EL3.EnPM2 == 0.
    - Accessed at EL2, EL1, or EL0.
  - All of the following are true:
    - PMUSERENR_EL0.UEN == 0 or PMUACR_EL1.F<m> == 0.
    - Accessed at EL0.
- Permitted writes of this field are ignored if any of the following are true:
  - All of the following are true:
    - EL3 is implemented and SCR_EL3.FGTEn2 == 0, or HDFGWTR2_EL2.nPMICFILTR_EL0 == 0.
    - FEAT_FGT2 is implemented.
    - EL2 is implemented and enabled in the current Security state.
    - Accessed at EL1 or EL0.
    - The Effective value of HCR_EL2.{E2H, TGE} is not {1, 1}.
  - All of the following are true:
    - Accessed at EL0.
    - PMUSERENR_EL0.IR == 1.
- Otherwise access to this field is W1C.

The reset behavior of this field is:

- On a Warm reset, this field resets to 0.

####
Otherwise:

Reserved, RES0.

#### C, bit [31]

Unsigned overflow flag for PMCCNTR_EL0 clear. On writes, allows software to clear the unsigned overflow flag for PMCCNTR_EL0 to 0. On reads, returns the unsigned overflow flag for PMCCNTR_EL0 overflow status.

C | Meaning
--- | ---
0b0 | PMCCNTR_EL0 has not overflowed.
0b1 | PMCCNTR_EL0 has overflowed.

PMCR_EL0.LC controls whether an overflow is detected from unsigned overflow of PMCCNTR_EL0[31:0] or unsigned overflow of PMCCNTR_EL0[63:0].

Accessing this field has the following behavior:

- Permitted reads and writes of this field are RAZ/WI if all of the following are true:
  - FEAT_PMUv3p9 is implemented.
  - Accessed at EL0.
  - PMUSERENR_EL0.UEN == 1.
  - PMUACR_EL1.C == 0.
- Permitted writes of this field are ignored if all of the following are true:
  - FEAT_PMUv3p9 is implemented.
  - Accessed at EL0.
  - PMUSERENR_EL0.{UEN,CR} == {1,1}.
- Otherwise access to this field is W1C.

The reset behavior of this field is:

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

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

Unsigned overflow flag for PMEVCNTR<m>_EL0 clear. On writes, allows software to clear the unsigned overflow flag for PMEVCNTR<m>_EL0 to 0. On reads, returns the unsigned overflow flag for PMEVCNTR<m>_EL0 overflow status.

P<m> | Meaning
--- | ---
0b0 | PMEVCNTR<m>_EL0 has not overflowed.
0b1 | PMEVCNTR<m>_EL0 has overflowed.

If FEAT_PMUv3p5 is implemented, MDCR_EL2.HLP and PMCR_EL0.LP control whether an overflow is detected from unsigned overflow of PMEVCNTR<m>_EL0[31:0] or unsigned overflow of PMEVCNTR<m>_EL0[63:0].

Accessing this field has the following behavior:

- Permitted reads and writes of this field are RAZ/WI if any of the following are true:
  - All of the following are true:
    - FEAT_PMUv3p9 is implemented.
    - Accessed at EL0.
    - PMUSERENR_EL0.UEN == 1.
    - PMUACR_EL1.P<m> == 0.
  - All of the following are true:
    - EL2 is implemented and enabled in the current Security state.
    - m >= UInt(MDCR_EL2.HPMN).
    - Accessed at EL0 or EL1.
  - m >= UInt(PMCR_EL0.N).
- Permitted writes of this field are ignored if all of the following are true:
  - FEAT_PMUv3p9 is implemented.
  - Accessed at EL0.
  - PMUSERENR_EL0.{UEN,ER} == {1,1}.
- Otherwise access to this field is W1C.

The reset behavior of this field is:

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

## Accessing PMOVSCLR_EL0

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

#### MRS <Xt>, PMOVSCLR_EL0

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

if PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TPM == '1' then UNDEFINED; elsif PMUSERENR_EL0.EN == '0' && (!IsFeatureImplemented(FEAT_PMUv3p9) || PMUSERENR_EL0.UEN == '0') 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.PMOVS == '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] = PMOVSCLR_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.PMOVS == '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] = PMOVSCLR_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] = PMOVSCLR_EL0; elsif PSTATE.EL == EL3 then X[t, 64] = PMOVSCLR_EL0;

#### MSR PMOVSCLR_EL0, <Xt>

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

if PSTATE.EL == EL0 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TPM == '1' then UNDEFINED; elsif PMUSERENR_EL0.EN == '0' && (!IsFeatureImplemented(FEAT_PMUv3p9) || PMUSERENR_EL0.UEN == '0') 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.PMOVS == '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 PMOVSCLR_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.PMOVS == '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 PMOVSCLR_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 PMOVSCLR_EL0 = X[t, 64]; elsif PSTATE.EL == EL3 then PMOVSCLR_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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