TRCVISSCTLR, ViewInst Start/Stop Control Register

The TRCVISSCTLR characteristics are:

Purpose

Use this to select, or read, the Single Address Comparators for the ViewInst start/stop function.

Configuration

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

This register is present only when FEAT_ETE is implemented, FEAT_TRC_EXT is implemented and UInt(TRCIDR4.NUMACPAIRS) > 0. Otherwise, direct accesses to TRCVISSCTLR are RES0.

Attributes

TRCVISSCTLR 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
STOP[15]	STOP[14]	STOP[13]	STOP[12]	STOP[11]	STOP[10]	STOP[9]	STOP[8]	STOP[7]	STOP[6]	STOP[5]	STOP[4]	STOP[3]	STOP[2]	STOP[1]	STOP[0]	START[15]	START[14]	START[13]	START[12]	START[11]	START[10]	START[9]	START[8]	START[7]	START[6]	START[5]	START[4]	START[3]	START[2]	START[1]	START[0]

STOP[<m>], bit [m+16], for m = 15 to 0

Selects whether Single Address Comparator <m> is used with the ViewInst start/stop function, for the purpose of stopping trace.

STOP[<m>]	Meaning
0b0	The Single Address Comparator <m>, is not selected as a stop resource.
0b1	The Single Address Comparator <m>, is selected as a stop resource.

This bit is RES0 if m >= 2 × TRCIDR4.NUMACPAIRS.

The reset behavior of this field is:

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

START[<m>], bit [m], for m = 15 to 0

Selects whether Single Address Comparator <m> is used with the ViewInst start/stop function, for the purpose of starting trace.

START[<m>]	Meaning
0b0	The Single Address Comparator <m>, is not selected as a start resource.
0b1	The Single Address Comparator <m>, is selected as a start resource.

This bit is RES0 if m >= 2 × TRCIDR4.NUMACPAIRS.

The reset behavior of this field is:

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

Accessing TRCVISSCTLR

Must be programmed if TRCIDR4.NUMACPAIRS > 0b0000.

For any 2 comparators selected for the ViewInst start/stop function, the comparator containing the lower address must be a lower numbered comparator.

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

TRCVISSCTLR can be accessed through the external debug interface:

Component	Offset	Instance
ETE	0x088	TRCVISSCTLR

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.

04/07/2023 11:27; 1b994cb0b8c6d1ae5a9a15edbc8bd6ce3b5c7d68