EDDEVID1, External Debug Device ID register 1
The EDDEVID1 characteristics are:
Purpose
Provides extra information for external debuggers about features of the debug 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.
Attributes
EDDEVID1 is a 32-bit register.
Field descriptions
The EDDEVID1 bit assignments are:
| 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 | PCSROffset | ||||||||||||||||||||||||||||||
Bits [31:4]
Reserved, RES0.
PCSROffset, bits [3:0]
This field indicates the offset applied to PC samples returned by reads of EDPCSR. Permitted values of this field in Armv8 are:
| PCSROffset | Meaning |
|---|---|
| 0b0000 |
EDPCSR not implemented. |
| 0b0010 |
EDPCSR implemented, and samples have no offset applied and do not sample the instruction set state in AArch32 state. |
When FEAT_PCSRv8p2 is implemented, the only permitted value is 0b0000.
FEAT_PCSRv8p2 implements the PC Sample-based Profiling Extension in the Performance Monitors register space, as indicated by the value of PMDEVID.PCSample.
Accessing the EDDEVID1
EDDEVID1 can be accessed through the external debug interface:
| Component | Offset | Instance |
|---|---|---|
| Debug | 0xFC4 | EDDEVID1 |
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.