TRCSEQSTR, Trace Sequencer State Register

The TRCSEQSTR characteristics are:

Purpose

Use this to set, or read, the Sequencer state.

Configuration

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

This register is present only when FEAT_ETE is implemented, FEAT_TRC_EXT is implemented, and TRCIDR5.NUMSEQSTATE != 0b000. Otherwise, direct accesses to TRCSEQSTR are RES0.

Attributes

TRCSEQSTR 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																														STATE

Bits [31:2]

Reserved, RES0.

STATE, bits [1:0]

Set or returns the state of the Sequencer.

STATE	Meaning
0b00	State 0.
0b01	State 1.
0b10	State 2.
0b11	State 3.

The reset behavior of this field is:

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

Accessing TRCSEQSTR

Must be programmed if TRCRSCTLR<a>.GROUP == 0b0010 and TRCRSCTLR<a>.SEQUENCER != 0b0000.

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

Reads from this register might return an UNKNOWN value if the trace unit is not in either of the Idle or Stable states.

TRCSEQSTR can be accessed through the external debug interface:

Component	Offset	Instance
ETE	0x11C	TRCSEQSTR

Accessible as follows:

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

21/03/2025 17:53; 154105dd5041532b480d9ef0c018b8420cbe5c19