The PMPCSR characteristics are:
Holds a sampled instruction address value.
This register is present only when FEAT_PMUv3_EXT is implemented and FEAT_PCSRv8p2 is implemented. Otherwise, direct accesses to PMPCSR are RES0.
PMPCSR is in the Core power domain.
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.
Support for 64-bit atomic reads is IMPLEMENTATION DEFINED. If 64-bit atomic reads are implemented, a 64-bit read of PMPCSR has the same side-effect as a 32-bit read of PMCSR[31:0] followed by a 32-bit read of PMPCSR[63:32], returning the combined value. For example, if the PE is in Debug state then a 64-bit atomic read returns bits[31:0] == 0xFFFFFFFF and bits[63:32] UNKNOWN.
PMPCSR is a 64-bit register.
This register is part of the PMU block.
| 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32 |
| 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 |
| NS | EL | T | NSE | RES0 | PCSample[55:32] | ||||||||||||||||||||||||||
| PCSample[31:0] | |||||||||||||||||||||||||||||||
Together with the NSE field, indicates the Security state that is associated with the most recent PMPCSR sample or, when it is read as a single atomic 64-bit read, the current PMPCSR sample.
| NSE | NS | Meaning |
|---|---|---|
| 0b0 | 0b0 | When Secure state is implemented, Secure. Otherwise reserved. |
| 0b0 | 0b1 | Non-secure. |
| 0b1 | 0b0 | Root. |
| 0b1 | 0b1 | Realm. |
Non-secure state sample. Indicates the Security state that is associated with the most recent PMPCSR sample or, when it is read as a single atomic 64-bit read, the current PMPCSR sample.
If EL3 is not implemented, this bit indicates the Effective value of SCR.NS.
| NS | Meaning |
|---|---|
| 0b0 |
Sample is from Secure state. |
| 0b1 |
Sample is from Non-secure state. |
The reset behavior of this field is:
Exception level status sample. Indicates the Exception level that is associated with the most recent PMPCSR sample or, when it is read as a single atomic 64-bit read, the current PMPCSR sample.
| EL | Meaning |
|---|---|
| 0b00 |
Sample is from EL0. |
| 0b01 |
Sample is from EL1. |
| 0b10 |
Sample is from EL2. |
| 0b11 |
Sample is from EL3. |
The reset behavior of this field is:
Transactional state of the sample. Indicates the Transactional state that is associated with the most recent PMPCSR sample or, when it is read as a single atomic 64-bit read, the current PMPCSR sample.
| T | Meaning |
|---|---|
| 0b0 |
Sample is from Non-transactional state. |
| 0b1 |
Sample is from Transactional state. |
The reset behavior of this field is:
Reserved, RES0.
Together with the NS field, indicates the Security state that is associated with the most recent PMPCSR sample or, when it is read as a single atomic 64-bit read, the current PMPCSR sample.
For a description of the values derived by evaluating NS and NSE together, see PMPCSR.NS.
Reserved, RES0.
Reserved, RES0.
Bits[55:32] of the sampled instruction address value. The translation regime that PMPCSR samples can be determined from PMPCSR.{NS,EL}.
The reset behavior of this field is:
Bits[31:0] of the sampled instruction address value.
PMPCSR[31:0] reads as 0xFFFFFFFF when any of the following are true:
If a branch instruction has retired since the PE left reset state, then the first read of PMPCSR[31:0] is permitted but not required to return 0xFFFFFFFF.
PMPCSR[31:0] reads as an UNKNOWN value when any of the following are true:
For the cases where a read of PMPCSR[31:0] returns 0xFFFFFFFF or an UNKNOWN value, the read has the side-effect of setting PMPCSR[63:32], PMCID1SR, PMCID2SR, and PMVIDSR to UNKNOWN values.
Otherwise, a read of PMPCSR[31:0] returns bits [31:0] of the sampled instruction address value and has the side-effect of indirectly writing to PMPCSR[63:32], PMCID1SR, PMCID2SR, and PMVIDSR. The translation regime that PMPCSR samples can be determined from PMPCSR.{NS,EL}.
For a read of PMPCSR[31:0] from the memory-mapped interface, if PMLSR.SLK == 1, meaning the OPTIONAL Software Lock is locked, then the side-effect of the access does not occur and PMPCSR[63:32], PMCID1SR, PMCID2SR, and PMVIDSR are unchanged.
The reset behavior of this field is:
IMPLEMENTATION DEFINED extensions to external debug might make the value of this register UNKNOWN, see 'Permitted behavior that might make the PC Sample-based profiling registers UNKNOWN'.
A 32-bit access to PMPCSR[63:32] does not update the PC sample registers. Only a 64-bit access to PMPCSR[63:0] or a 32-bit access to PMPCSR[31:0] updates the PC sample registers. This includes the value a subsequent 32-bit read of PMPCSR[63:32] will return.
Accesses to this register use the following encodings:
[63:0] Accessible at offset 0x200 from PMU
[31:0] Accessible at offset 0x200 from PMU
[63:32] Accessible at offset 0x204 from PMU
[63:0] Accessible at offset 0x220 from PMU
[31:0] Accessible at offset 0x220 from PMU
[63:32] Accessible at offset 0x224 from PMU
26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6
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