PMCID2SR, CONTEXTIDR_EL2 Sample Register

The PMCID2SR characteristics are:

Purpose

Contains the sampled value of CONTEXTIDR_EL2, captured on reading PMPCSR[31:0].

This register is part of the Performance Monitors registers functional group.

Usage constraints

This register is accessible as follows:

OffDLKOSLKSLKDefault
ErrorErrorErrorRORO

IMPLEMENTATION DEFINED extensions to external debug might make the value of this register UNKNOWN, see the section describing 'Permitted behavior that might make the PC Sample-based profiling registers UNKNOWN' in chapter H7 'The PC Sample-based Profiling Extension' of the ARM Architecture Reference Manual, for ARMv8-A architecture profile.

Configuration

PMCID2SR is in the Core power domain.

Fields in this register reset to architecturally UNKNOWN values. These apply only on a Cold reset. The register is not affected by a Warm reset and is not affected by an External debug reset.

Implemented only when ARMv8.2-PCSample is implemented.

Note

Before ARMv8.2, the PC Sample-based Profiling Extension can be implemented in the external debug register space, as indicated by the value of EDDEVID.PCSample.

If EL2 is not implemented, this register is RES0.

This register is introduced in ARMv8.2.

Attributes

PMCID2SR is a 32-bit register.

Field descriptions

The PMCID2SR bit assignments are:

313029282726252423222120191817161514131211109876543210
CONTEXTIDR_EL2

CONTEXTIDR_EL2, bits [31:0]

Context ID. The value of CONTEXTIDR that is associated with the most recent PMPCSR sample.

Because the value written to PMCID2SR is an indirect read of CONTEXTIDR, therefore it is CONSTRAINED UNPREDICTABLE whether PMCID2SR is set to the original or new value if a read of PMPCSR samples:

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

Accessing the PMCID2SR

PMCID2SR can be accessed through the external debug interface:

ComponentOffset
PMU 0x22C



28/09/2017 08:24

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