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PMEVTYPER<n>_EL0, Performance Monitors Event Type Registers, n = 0 - 30

The PMEVTYPER<n>_EL0 characteristics are:

Purpose

Configures event counter n, where n is 0 to 30.

Configuration

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

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

PMEVTYPER<n>_EL0 is in the Core power domain. RW fields in this register reset to architecturally UNKNOWN values. These apply on a Warm or Cold reset. The register is not affected by an External debug reset.

Attributes

PMEVTYPER<n>_EL0 is a 32-bit register.

Field descriptions

The PMEVTYPER<n>_EL0 bit assignments are:

313029282726252423222120191817161514131211109876543210
PUNSKNSUNSHMMTSH00000000evtCount[15:10]evtCount[9:0]

P, bit [31]

Privileged filtering bit. Controls counting in EL1. If EL3 is implemented, then counting in Non-secure EL1 is further controlled by the PMEVTYPER<n>_EL0.NSK bit. The possible values of this bit are:

PMeaning
0b0

Count events in EL1.

0b1

Do not count events in EL1.

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

U, bit [30]

User filtering bit. Controls counting in EL0. If EL3 is implemented, then counting in Non-secure EL0 is further controlled by the PMEVTYPER<n>_EL0.NSU bit. The possible values of this bit are:

UMeaning
0b0

Count events in EL0.

0b1

Do not count events in EL0.

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

NSK, bit [29]

Non-secure EL1 (kernel) modes filtering bit. Controls counting in Non-secure EL1. If EL3 is not implemented, this bit is RES0.

If the value of this bit is equal to the value of the PMEVTYPER<n>_EL0.P bit, events in Non-secure EL1 are counted.

Otherwise, events in Non-secure EL1 are not counted.

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

NSU, bit [28]

Non-secure EL0 (Unprivileged) filtering bit. Controls counting in Non-secure EL0. If EL3 is not implemented, this bit is RES0.

If the value of this bit is equal to the value of the PMEVTYPER<n>_EL0.U bit, events in Non-secure EL0 are counted.

Otherwise, events in Non-secure EL0 are not counted.

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

NSH, bit [27]

EL2 (Hypervisor) filtering bit. Controls counting in EL2. If EL2 is not implemented, this bit is RES0. If Secure EL2 is implemented, counting in Secure EL2 is further controlled by the PMEVTYPER<n>_EL0.SH bit.

NSHMeaning
0b0

Do not count events in EL2.

0b1

Count events in EL2.

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

M, bit [26]

Secure EL3 filtering bit. If EL3 is not implemented, this bit is RES0.

If the value of this bit is equal to the value of the PMEVTYPER<n>_EL0.P bit, cycles in Secure EL3 are counted.

Otherwise, cycles in Secure EL3 are not counted.

Most applications can ignore this field and set its value to 0b0.

Note

This field is not visible in the AArch32 PMEVTYPER<n> System register.

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

MT, bit [25]

Multithreading. When the implementation is multi-threaded, the valid values for this bit are:

MTMeaning
0b0

Count events only on controlling PE.

0b1

Count events from any PE with the same affinity at level 1 and above as this PE.

When the implementation is not multi-threaded, this bit is RES0.

Note
  • When the lowest level of affinity consists of logical PEs that are implemented using a multi-threading type approach, an implementation is described as multi-threaded. That is, the performance of PEs at the lowest affinity level is highly interdependent. On such an implementation, the value of the MPIDR_EL1.MT bit, when read at the highest implemented Exception level, is 0b1.
  • Events from a different thread of a multithreaded implementation are not Attributable to the thread counting the event.

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

SH, bit [24]

When ARMv8.4-SecEL2 is implemented:

Secure EL2 filtering.

If the value of this bit is not equal to the value of the PMEVTYPER<n>_EL0.NSH bit, events in Secure EL2 are counted.

Otherwise, events in Secure EL2 are not counted.

If Secure EL2 is not implemented or is disabled, this field is RES0.

Note

This field is not visible in the AArch32 PMEVTYPER<n> System register.

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


Otherwise:

Reserved, RES0.

Bits [23:16]

Reserved, RES0.

evtCount[15:10], bits [15:10]

From Armv8.1:

Extension to evtCount[9:0]. See evtCount[9:0] for more details.

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


Otherwise:

Reserved, RES0.

evtCount[9:0], bits [9:0]

Event to count. The event number of the event that is counted by event counter PMEVCNTR<n>_EL0.

Software must program this field with an event that is supported by the PE being programmed.

There are three types of event:

  • Common architectural and microarchitectural events.

  • Arm recommended common architectural and microarchitectural events.

  • IMPLEMENTATION DEFINED events.

The ranges of event numbers allocated to each type of event are shown in Allocation of the PMU event number space.

If evtCount is programmed to an event that is reserved or not supported by the PE, the behavior depends on the event type:

  • For the range 0x000 to 0x03F, no events are counted, and the value returned by a direct or external read of the evtCount field is the value written to the field.

  • For IMPLEMENTATION DEFINED events, it is UNPREDICTABLE what event, if any, is counted, and the value returned by a direct or external read of the evtCount field is UNKNOWN.

Note

UNPREDICTABLE means the event must not expose privileged information.

Arm recommends that the behavior across a family of implementations is defined such that if a given implementation does not include an event from a set of common IMPLEMENTATION DEFINED events, then no event is counted and the value read back on evtCount is the value written.

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

Accessing the PMEVTYPER<n>_EL0

Note

SoftwareLockStatus() depends on the type of access attempted and AllowExternalPMUAccess() has a new definition from Armv8.4. Refer to the Pseudocode definitions for more information.

PMEVTYPER<n>_EL0 can be accessed through the external debug interface:

ComponentOffsetInstance
PMU0x400 + 4nPMEVTYPER<n>_EL0

This interface is accessible as follows:

  • When IsCorePowered(), !DoubleLockStatus(), !OSLockStatus(), AllowExternalPMUAccess() and SoftwareLockStatus() access to this register is RO.
  • When IsCorePowered(), !DoubleLockStatus(), !OSLockStatus(), AllowExternalPMUAccess() and !SoftwareLockStatus() access to this register is RW.
  • Otherwise access to this register returns an Error.


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