PMDEVID, Performance Monitors Device ID register
The PMDEVID characteristics are:
Purpose
Provides information about features of the Performance Monitors implementation.
Configuration
If FEAT_DoPD is implemented, this register is in the Core power domain.
If FEAT_DoPD is not implemented, this register is in the Debug power domain.
This register is required from Armv8.2 and in any implementation that includes FEAT_PCSRv8p2. Otherwise, its location is RES0.
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.
Attributes
PMDEVID is a 32-bit register.
Field descriptions
The PMDEVID bit assignments are:
Bits [31:4]
Reserved, RES0.
PCSample, bits [3:0]
Indicates the level of PC Sample-based Profiling support using Performance Monitors registers.
| PCSample | Meaning |
|---|---|
| 0b0000 |
PC Sample-based Profiling Extension is not implemented in the Performance Monitors register space. |
| 0b0001 |
PC Sample-based Profiling Extension is implemented in the Performance Monitors register space. |
All other values are reserved.
FEAT_PCSRv8p2 implements the functionality identified by the value 0b0001.
Accessing the PMDEVID
PMDEVID can be accessed through the external debug interface:
| Component | Offset | Instance |
|---|---|---|
| PMU | 0xFC8 | PMDEVID |
This interface is accessible as follows:
- When FEAT_DoPD is not implemented or IsCorePowered() accesses to this register are RO.
- Otherwise accesses to this register generate an error response.