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TRCQCTLR

TRCQCTLR, Trace Q Element Control Register

The TRCQCTLR characteristics are:

Purpose

Controls when Q elements are enabled.

Configuration

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

This register is present only when FEAT_ETE is implemented, System register access to the trace unit registers is implemented, and TRCIDR0.QFILT == '1'. Otherwise, direct accesses to TRCQCTLR are UNDEFINED.

Attributes

TRCQCTLR is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
RES0MODERANGE[7]RANGE[6]RANGE[5]RANGE[4]RANGE[3]RANGE[2]RANGE[1]RANGE[0]

Bits [63:9]

Reserved, RES0.

MODE, bit [8]

Selects whether the Address Range Comparators selected by TRCQCTLR.RANGE indicate address ranges where the trace unit is permitted to generate Q elements or address ranges where the trace unit is not permitted to generate Q elements:

MODEMeaning
0b0

Exclude mode.

The Address Range Comparators selected by TRCQCTLR.RANGE indicate address ranges where the trace unit must not generate Q elements. If no ranges are selected, Q elements are permitted across the entire memory map.

0b1

Include Mode.

The Address Range Comparators selected by TRCQCTLR.RANGE indicate address ranges where the trace unit can generate Q elements. If all the implemented bits in RANGE are set to 0 then Q elements are disabled.

The reset behavior of this field is:

RANGE[<m>], bit [m], for m = 7 to 0

Specifies whether Address Range Comparator <m> controls Q elements.

RANGE[<m>]Meaning
0b0

The address range that Address Range Comparator <m> defines is not selected.

0b1

The address range that Address Range Comparator <m> defines is selected.

The reset behavior of this field is:

Accessing this field has the following behavior:

Accessing TRCQCTLR

Must be programmed if TRCCONFIGR.QE != 0b00.

Writes are CONSTRAINED UNPREDICTABLE if the trace unit is not in the Idle state.

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

MRS <Xt>, TRCQCTLR

op0op1CRnCRmop2
0b100b0010b00000b00010b001

if !(IsFeatureImplemented(FEAT_ETE) && IsFeatureImplemented(FEAT_TRC_SR) && TRCIDR0().QFILT == '1') then Undefined(); elsif 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().TRC == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3().TTA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1().OSLK == '0' && HaltingAllowed() && EDSCR2().TTA == '1' then Halt(DebugHalt_SoftwareAccess); else X{64}(t) = TRCQCTLR(); end; 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); end; elsif IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1().OSLK == '0' && HaltingAllowed() && EDSCR2().TTA == '1' then Halt(DebugHalt_SoftwareAccess); else X{64}(t) = TRCQCTLR(); end; elsif PSTATE.EL == EL3 then if CPTR_EL3().TTA == '1' then AArch64_SystemAccessTrap(EL3, 0x18); elsif IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1().OSLK == '0' && HaltingAllowed() && EDSCR2().TTA == '1' then Halt(DebugHalt_SoftwareAccess); else X{64}(t) = TRCQCTLR(); end; end;

MSR TRCQCTLR, <Xt>

op0op1CRnCRmop2
0b100b0010b00000b00010b001

if !(IsFeatureImplemented(FEAT_ETE) && IsFeatureImplemented(FEAT_TRC_SR) && TRCIDR0().QFILT == '1') then Undefined(); elsif 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') && HDFGWTR_EL2().TRC == '1' then AArch64_SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3().TTA == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; elsif IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1().OSLK == '0' && HaltingAllowed() && EDSCR2().TTA == '1' then Halt(DebugHalt_SoftwareAccess); else TRCQCTLR() = X{64}(t); end; 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); end; elsif IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1().OSLK == '0' && HaltingAllowed() && EDSCR2().TTA == '1' then Halt(DebugHalt_SoftwareAccess); else TRCQCTLR() = X{64}(t); end; elsif PSTATE.EL == EL3 then if CPTR_EL3().TTA == '1' then AArch64_SystemAccessTrap(EL3, 0x18); elsif IsFeatureImplemented(FEAT_TRBE_EXT) && OSLSR_EL1().OSLK == '0' && HaltingAllowed() && EDSCR2().TTA == '1' then Halt(DebugHalt_SoftwareAccess); else TRCQCTLR() = X{64}(t); end; end;


2026-03-26 20:27:25, 2026-03_rel

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