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TRCIDR1: Trace ID Register 1

Purpose

Returns the tracing capabilities of the trace unit.

Configuration

AArch64 System register TRCIDR1 bits [31:0] are architecturally mapped to External register TRCIDR1[31:0].

This register is present only when FEAT_ETE is implemented and System register access to the trace unit registers is implemented. Otherwise, direct accesses to TRCIDR1 are UNDEFINED.

Attributes

TRCIDR1 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
DESIGNERRES0RES1TRCARCHMAJTRCARCHMINREVISION

Bits [63:32]

Reserved, RES0.

DESIGNER, bits [31:24]

Indicates which company designed the trace unit. The permitted values of this field are the same as MIDR_EL1.Implementer.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Bits [23:16]

Reserved, RES0.

Bits [15:12]

Reserved, RES1.

TRCARCHMAJ, bits [11:8]

Major architecture version.

TRCARCHMAJMeaning
0b1111

If both TRCIDR1.TRCARCHMAJ and TRCIDR1.TRCARCHMIN == 0xF then refer to TRCDEVARCH.

All other values are reserved.

This field reads as 0b1111.

Access to this field is RO.

TRCARCHMIN, bits [7:4]

Minor architecture version.

TRCARCHMINMeaning
0b1111

If both TRCIDR1.TRCARCHMAJ and TRCIDR1.TRCARCHMIN == 0xF then refer to TRCDEVARCH.

All other values are reserved.

This field reads as 0b1111.

Access to this field is RO.

REVISION, bits [3:0]

Implementation revision.

Returns an IMPLEMENTATION DEFINED value that identifies the revision of the trace unit.

Arm deprecates any use of this field and recommends that implementations set this field to zero.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Accessing TRCIDR1

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, TRCIDR1

op0op1CRnCRmop2
0b100b0010b00000b10010b111

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && CPTR_EL3.TTA == '1' then UNDEFINED; elsif CPACR_EL1.TTA == '1' then AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && CPTR_EL2.TTA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGRTR_EL2.TRCID == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TTA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR2.TTA == '1' then Halt(DebugHalt_SoftwareAccess); else X[t, 64] = TRCIDR1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && CPTR_EL3.TTA == '1' then UNDEFINED; elsif CPTR_EL2.TTA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TTA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif !ELUsingAArch32(EL1) && IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR2.TTA == '1' then Halt(DebugHalt_SoftwareAccess); else X[t, 64] = TRCIDR1; elsif PSTATE.EL == EL3 then if CPTR_EL3.TTA == '1' then AArch64.SystemAccessTrap(EL3, 0x18); elsif !ELUsingAArch32(EL1) && IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR2.TTA == '1' then Halt(DebugHalt_SoftwareAccess); else X[t, 64] = TRCIDR1;