TRCQCTLR: Trace Q Element Control Register

Purpose

Controls when Q elements are enabled.

Configuration

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

This register is present only when FEAT_ETE is implemented, FEAT_TRC_EXT is implemented and TRCIDR0.QFILT == 1. Otherwise, direct accesses to TRCQCTLR are RES0.

Attributes

TRCQCTLR is a 32-bit register.

Field descriptions

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
RES0																							MODE	RANGE[7]	RANGE[6]	RANGE[5]	RANGE[4]	RANGE[3]	RANGE[2]	RANGE[1]	RANGE[0]

Bits [31:9]

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:

MODE	Meaning
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.

MODE

Meaning

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:

On a Trace unit reset, this field resets to an architecturally UNKNOWN value.

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:

On a Trace unit reset, this field resets to an architecturally UNKNOWN value.

Accessing this field has the following behavior:

When m >= UInt(TRCIDR4.NUMACPAIRS), access to this field is RES0.
Otherwise, access to this field is RW.

Accessing TRCQCTLR

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

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

TRCQCTLR can be accessed through the external debug interface:

Component	Offset	Instance
ETE	0x044	TRCQCTLR

This interface is accessible as follows:

When OSLockStatus(), or !AllowExternalTraceAccess() or !IsTraceCorePowered(), accesses to this register generate an error response.
Otherwise, accesses to this register are RW.