TRCIDR2, ID Register 2
The TRCIDR2 characteristics are:
Purpose
Returns the tracing capabilities of the trace unit.
Configuration
External register TRCIDR2 bits [31:0] are architecturally mapped to AArch64 System register TRCIDR2[31:0] .
This register is present only when FEAT_ETE is implemented. Otherwise, direct accesses to TRCIDR2 are RES0.
Attributes
TRCIDR2 is a 32-bit register.
Field descriptions
The TRCIDR2 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 |
| WFXMODE | VMIDOPT | CCSIZE | DVSIZE | DASIZE | VMIDSIZE | CIDSIZE | IASIZE | ||||||||||||||||||||||||
WFXMODE, bit [31]
Indicates whether WFI and WFE instructions are classified as P0 instructions:
| WFXMODE | Meaning |
|---|---|
| 0b0 |
WFI and WFE instructions are not classified as P0 instructions. |
| 0b1 |
WFI and WFE instructions are classified as P0 instructions. |
VMIDOPT, bits [30:29]
Indicates the options for Virtual context identifier selection.
| VMIDOPT | Meaning |
|---|---|
| 0b00 |
Virtual context identifier selection not supported. TRCCONFIGR.VMIDOPT is RES0. |
| 0b01 |
Virtual context identifier selection supported. TRCCONFIGR.VMIDOPT is implemented. |
| 0b10 |
Virtual context identifier selection not supported. TRCCONFIGR.VMIDOPT is RES1. |
All other values are reserved.
If TRCIDR2.VMIDSIZE == 0b00000 then this field is 0b00.
If TRCIDR2.VMIDSIZE != 0b00000 then this field is 0b10.
CCSIZE, bits [28:25]
When TRCIDR0.TRCCCI == 1:
When TRCIDR0.TRCCCI == 1:
Indicates the size of the cycle counter.
| CCSIZE | Meaning |
|---|---|
| 0b0000 |
The cycle counter is 12 bits in length. |
| 0b0001 |
The cycle counter is 13 bits in length. |
| 0b0010 |
The cycle counter is 14 bits in length. |
| 0b0011 |
The cycle counter is 15 bits in length. |
| 0b0100 |
The cycle counter is 16 bits in length. |
| 0b0101 |
The cycle counter is 17 bits in length. |
| 0b0110 |
The cycle counter is 18 bits in length. |
| 0b0111 |
The cycle counter is 19 bits in length. |
| 0b1000 |
The cycle counter is 20 bits in length. |
All other values are reserved.
Otherwise:
Otherwise:
Reserved, RES0.
DVSIZE, bits [24:20]
When TRCIDR0.TRCDATA != 0b00:
When TRCIDR0.TRCDATA != 0b00:
Indicates the data value size in bytes. Data tracing is not implemented in ETE and this field is reserved for other trace architectures. Allocated in other trace architectures.
| DVSIZE | Meaning |
|---|---|
| 0b00000 |
Data value tracing not implemented. |
| 0b00100 |
Data value tracing has a maximum of 32-bit data values. |
| 0b01000 |
Data value tracing has a maximum of 64-bit data values. |
All other values are reserved.
Otherwise:
Otherwise:
Reserved, RES0.
DASIZE, bits [19:15]
When TRCIDR0.TRCDATA != 0b00:
When TRCIDR0.TRCDATA != 0b00:
Indicates the data address size in bytes. Data tracing is not implemented in ETE and this field is reserved for other trace architectures. Allocated in other trace architectures.
| DASIZE | Meaning |
|---|---|
| 0b00000 |
Data address tracing not implemented. |
| 0b00100 |
Data address tracing has a maximum of 32-bit data addresses. |
| 0b01000 |
Data address tracing has a maximum of 64-bit data addresses. |
All other values are reserved.
Otherwise:
Otherwise:
Reserved, RES0.
VMIDSIZE, bits [14:10]
Indicates the trace unit Virtual context identifier size.
| VMIDSIZE | Meaning |
|---|---|
| 0b00000 |
Virtual context identifier tracing is not supported. |
| 0b00001 |
8-bit Virtual context identifier size. |
| 0b00010 |
16-bit Virtual context identifier size. |
| 0b00100 |
32-bit Virtual context identifier size. |
All other values are reserved.
If the PE does not implement EL2 then this field is 0b00000.
If the PE implements EL2 then this field is 0b00100.
CIDSIZE, bits [9:5]
Indicates the Context identifier size.
| CIDSIZE | Meaning |
|---|---|
| 0b00000 |
Context identifier tracing is not supported. |
| 0b00100 |
32-bit Context identifier size. |
All other values are reserved.
This field reads as 0b00100.
IASIZE, bits [4:0]
Virtual instruction address size.
| IASIZE | Meaning |
|---|---|
| 0b00100 |
Maximum of 32-bit instruction address size. |
| 0b01000 |
Maximum of 64-bit instruction address size. |
All other values are reserved.
This field reads as 0b01000.
Accessing the TRCIDR2
TRCIDR2 can be accessed through the external debug interface:
| Component | Offset |
|---|---|
| ETE | 0x1E8 |
This interface is accessible as follows:
- When OSLockStatus() or !IsTraceCorePowered() accesses to this register generate an error response.
- Otherwise accesses to this register are RO.