TRCIDR4 Trace ID Register 4 when FEAT_ETE is implemented and FEAT_TRC_EXT is implemented ETE 0x1F0 TRCIDR4 When OSLockStatus() or !IsTraceCorePowered() ERROR RO TRCIDR4 Architectural AArch64 31 0 31 0 31 0 31 0 Returns the tracing capabilities of the trace unit. Trace TRCIDR4 is a 32-bit register. NUMVMIDC 31 28 31:28 Indicates the number of Virtual Context Identifier Comparators that are available for tracing. All other values are reserved. If the PE does not implement EL2 then this field is 0b0000. 0b0000..0b1000 The number of Virtual Context Identifier Comparators in this implementation. RO NUMCIDC 27 24 27:24 Indicates the number of Context Identifier Comparators that are available for tracing. All other values are reserved. 0b0000..0b1000 The number of Context Identifier Comparators in this implementation. RO NUMSSCC 23 20 23:20 Indicates the number of Single-shot Comparator Controls that are available for tracing. All other values are reserved. 0b0000..0b1000 The number of Single-shot Comparator Controls in this implementation. RO NUMRSPAIR 19 16 19:16 Indicates the number of resource selector pairs that are available for tracing. All other values are reserved. 0b0000 This implementation has zero resource selector pairs. 0b0001..0b1111 The number of resource selector pairs in this implementation, minus one. RO NUMPC 15 12 15:12 Indicates the number of PE Comparator Inputs that are available for tracing. All other values are reserved. 0b0000..0b1000 The number of PE Comparator Inputs in this implementation. RO 11 9 11:9 Reserved, RES0. SUPPDAC 8 8 0 Indicates whether data address comparisons are implemented. Data address comparisons are not implemented in ETE and are reserved for other trace architectures. Allocated in other trace architectures. This field reads as 0. 0b0 Data address comparisons not implemented. 0b1 Data address comparisons implemented. RO When TRCIDR4.NUMACPAIRS != '0000' 8 8 8 Reserved, RES0. Otherwise NUMDVC 7 4 7:4 Indicates the number of data value comparators. Data value comparators are not implemented in ETE and are reserved for other trace architectures. Allocated in other trace architectures. All other values are reserved. This field reads as 0b0000. 0b0000..0b1000 The number of data value comparators in this implementation. RO NUMACPAIRS 3 0 3:0 Indicates the number of Address Comparator pairs that are available for tracing. All other values are reserved. 0b0000..0b1000 The number of Address Comparator pairs in this implementation. RO 2026-03-26 20:27:25 2026-03_rel