TRCIDR0

External register TRCIDR0 bits [31:0] are architecturally mapped to AArch64 System register TRCIDR0[31:0].

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

Attributes

Field descriptions

Bit [31]

COMMTRANS, bit [30]

Transaction Start element behavior.

The value of this field is an IMPLEMENTATION DEFINED choice of:

COMMTRANS	Meaning
0b0	Transaction Start elements are P0 elements.
0b1	Transaction Start elements are not P0 elements.

Access to this field is RO.

COMMOPT, bit [29]

Indicates the contents and encodings of Cycle count packets.

The value of this field is an IMPLEMENTATION DEFINED choice of:

COMMOPT	Meaning
0b0	Commit mode 0.
0b1	Commit mode 1.

The Commit mode defines the contents and encodings of Cycle Count packets, in particular how Commit elements are indicated by these packets. See the descriptions of these packets for more details.

Accessing this field has the following behavior:

Access is RAO/WI if TRCIDR0.TRCCCI == 1 and UInt(TRCIDR8.MAXSPEC) == 0x0.
When TRCIDR0.TRCCCI == 0, access to this field is RAZ/WI.
Otherwise, access to this field is RO.

TSSIZE, bits [28:24]

Indicates that the trace unit implements Global timestamping and the size of the timestamp value.

The value of this field is an IMPLEMENTATION DEFINED choice of:

TSSIZE	Meaning
0b00000	Global timestamping not implemented.
0b01000	Global timestamping implemented with a 64-bit timestamp value.

All other values are reserved.

This field reads as 0b01000.

Access to this field is RO.

TSMARK, bit [23]

Indicates whether Timestamp Marker elements are generated.

The value of this field is an IMPLEMENTATION DEFINED choice of:

TSMARK	Meaning
0b0	Timestamp Marker elements are not generated.
0b1	Timestamp Marker elements are generated.

Access to this field is RO.

ITE, bit [22]

Indicates whether Instrumentation Trace is implemented.

The value of this field is an IMPLEMENTATION DEFINED choice of:

ITE	Meaning
0b0	Instrumentation Trace not implemented.
0b1	Instrumentation Trace implemented.

This field has the value 1 if FEAT_ITE is implemented.

Access to this field is RO.

Bits [21:18]

TRCEXDATA, bit [17]
When TRCIDR0.TRCDATA != 0b00:

Indicates if the trace unit implements tracing of data transfers for exceptions and exception returns. Data tracing is not implemented in ETE and this field is reserved for other trace architectures. Allocated in other trace architectures.

The value of this field is an IMPLEMENTATION DEFINED choice of:

TRCEXDATA	Meaning
0b0	Tracing of data transfers for exceptions and exception returns not implemented.
0b1	Tracing of data transfers for exceptions and exception returns implemented.

Access to this field is RO.

Otherwise:

QSUPP, bits [16:15]

Indicates that the trace unit implements Q element support.

The value of this field is an IMPLEMENTATION DEFINED choice of:

QSUPP	Meaning
0b00	Q element support is not implemented.
0b01	Q element support is implemented, and only supports Q elements with instruction counts.
0b10	Q element support is implemented, and only supports Q elements without instruction counts.
0b11	Q element support is implemented, and supports: Q elements with instruction counts. Q elements without instruction counts.

Access to this field is RO.

QFILT, bit [14]

Indicates if the trace unit implements Q element filtering.

The value of this field is an IMPLEMENTATION DEFINED choice of:

QFILT	Meaning
0b0	Q element filtering is not implemented.
0b1	Q element filtering is implemented.

If TRCIDR0.QSUPP == 0b00 then this field is 0.

Access to this field is RO.

CONDTYPE, bits [13:12]
When TRCIDR0.TRCCOND == 1:

Indicates how conditional instructions are traced. Conditional instruction tracing is not implemented in ETE and this field is reserved for other trace architectures. Allocated in other trace architectures.

The value of this field is an IMPLEMENTATION DEFINED choice of:

CONDTYPE	Meaning
0b00	Conditional instructions are traced with an indication of whether they pass or fail their condition code check.
0b01	Conditional instructions are traced with an indication of the APSR condition flags.

All other values are reserved.

Access to this field is RO.

Otherwise:

NUMEVENT, bits [11:10]
When TRCIDR4.NUMRSPAIR == 0b0000:

Indicates the number of ETEEvents implemented.

NUMEVENT	Meaning
0b00	The trace unit supports 0 ETEEvents.

All other values are reserved.

Access to this field is RO.

When TRCIDR4.NUMRSPAIR != 0b0000:

Indicates the number of ETEEvents implemented.

The value of this field is an IMPLEMENTATION DEFINED choice of:

NUMEVENT	Meaning
0b00	The trace unit supports 1 ETEEvent.
0b01	The trace unit supports 2 ETEEvents.
0b10	The trace unit supports 3 ETEEvents.
0b11	The trace unit supports 4 ETEEvents.

Access to this field is RO.

Otherwise:

RETSTACK, bit [9]

Indicates if the trace unit supports the return stack.

The value of this field is an IMPLEMENTATION DEFINED choice of:

RETSTACK	Meaning
0b0	Return stack not implemented.
0b1	Return stack implemented.

Access to this field is RO.

Bit [8]

TRCCCI, bit [7]

Indicates if the trace unit implements cycle counting.

The value of this field is an IMPLEMENTATION DEFINED choice of:

TRCCCI	Meaning
0b0	Cycle counting not implemented.
0b1	Cycle counting implemented.

This field reads as 1.

Access to this field is RO.

TRCCOND, bit [6]

Indicates if the trace unit implements conditional instruction tracing. Conditional instruction tracing is not implemented in ETE and this field is reserved for other trace architectures.

The value of this field is an IMPLEMENTATION DEFINED choice of:

TRCCOND	Meaning
0b0	Conditional instruction tracing not implemented.
0b1	Conditional instruction tracing implemented.

This field reads as 0.

Access to this field is RO.

TRCBB, bit [5]

Indicates if the trace unit implements branch broadcasting.

The value of this field is an IMPLEMENTATION DEFINED choice of:

TRCBB	Meaning
0b0	Branch broadcasting not implemented.
0b1	Branch broadcasting implemented.

This field reads as 1.

Access to this field is RO.

TRCDATA, bits [4:3]

Indicates if the trace unit implements data tracing. Data tracing is not implemented in ETE and this field is reserved for other trace architectures.

The value of this field is an IMPLEMENTATION DEFINED choice of:

TRCDATA	Meaning
0b00	Data tracing not implemented.
0b11	Data tracing implemented.

All other values are reserved.

This field reads as 0b00.

Access to this field is RO.

INSTP0, bits [2:1]

Indicates if load and store instructions are P0 instructions. Load and store instructions as P0 instructions is not implemented in ETE and this field is reserved for other trace architectures.

The value of this field is an IMPLEMENTATION DEFINED choice of:

INSTP0	Meaning
0b00	Load and store instructions are not P0 instructions.
0b11	Load and store instructions are P0 instructions.

All other values are reserved.

When FEAT_ETE is implemented, the only permitted value is 0b00.

Access to this field is RO.

Bit [0]

Accessing TRCIDR0

TRCIDR0 can be accessed through the external debug interface:

TRCIDR0, Trace ID Register 0

Purpose

Configuration

Attributes

Field descriptions

Bit [31]

COMMTRANS, bit [30]

COMMOPT, bit [29]

TSSIZE, bits [28:24]

TSMARK, bit [23]

ITE, bit [22]

Bits [21:18]

TRCEXDATA, bit [17]
When TRCIDR0.TRCDATA != 0b00:

Otherwise:

QSUPP, bits [16:15]

QFILT, bit [14]

CONDTYPE, bits [13:12]
When TRCIDR0.TRCCOND == 1:

Otherwise:

NUMEVENT, bits [11:10]
When TRCIDR4.NUMRSPAIR == 0b0000:

When TRCIDR4.NUMRSPAIR != 0b0000:

Otherwise:

RETSTACK, bit [9]

Bit [8]

TRCCCI, bit [7]

TRCCOND, bit [6]

TRCBB, bit [5]

TRCDATA, bits [4:3]

INSTP0, bits [2:1]

Bit [0]

Accessing TRCIDR0

TRCIDR0 can be accessed through the external debug interface:

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	COMMTRANS	COMMOPT	TSSIZE					TSMARK	ITE	RES0				TRCEXDATA	QSUPP		QFILT	CONDTYPE		NUMEVENT		RETSTACK	RES0	TRCCCI	TRCCOND	TRCBB	TRCDATA		INSTP0		RES1

TRCIDR0, Trace ID Register 0

Purpose

Configuration

Attributes

Field descriptions

Bit [31]

COMMTRANS, bit [30]

COMMOPT, bit [29]

TSSIZE, bits [28:24]

TSMARK, bit [23]

ITE, bit [22]

Bits [21:18]

TRCEXDATA, bit [17]When TRCIDR0.TRCDATA != 0b00:

Otherwise:

QSUPP, bits [16:15]

QFILT, bit [14]

CONDTYPE, bits [13:12]When TRCIDR0.TRCCOND == 1:

Otherwise:

NUMEVENT, bits [11:10]When TRCIDR4.NUMRSPAIR == 0b0000:

When TRCIDR4.NUMRSPAIR != 0b0000:

Otherwise:

RETSTACK, bit [9]

Bit [8]

TRCCCI, bit [7]

TRCCOND, bit [6]

TRCBB, bit [5]

TRCDATA, bits [4:3]

INSTP0, bits [2:1]

Bit [0]

Accessing TRCIDR0

TRCIDR0 can be accessed through the external debug interface:

TRCEXDATA, bit [17]
When TRCIDR0.TRCDATA != 0b00:

CONDTYPE, bits [13:12]
When TRCIDR0.TRCCOND == 1:

NUMEVENT, bits [11:10]
When TRCIDR4.NUMRSPAIR == 0b0000: