EDRCR, External Debug Reserve Control Register

The EDRCR characteristics are:

Purpose

This register is used to allow imprecise entry to Debug state and clear sticky bits in EDSCR.

Configuration

EDRCR is in the Core power domain.

Attributes

EDRCR 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																											CBRRQ	CSPA	CSE	RES0

Bits [31:5]

Reserved, RES0.

CBRRQ, bit [4]

Allow imprecise entry to Debug state. The actions on writing to this bit are:

CBRRQ	Meaning
0b0	No action.
0b1	Allow imprecise entry to Debug state, for example by canceling pending bus accesses.

Setting this bit to 1 allows a debugger to request imprecise entry to Debug state. An External Debug Request debug event must be pending before the debugger sets this bit to 1.

This feature is optional. If this feature is not implemented, writes to this bit are ignored.

CSPA, bit [3]

Clear Sticky Pipeline Advance. This bit is used to clear the EDSCR.PipeAdv bit to 0. The actions on writing to this bit are:

CSPA	Meaning
0b0	No action.
0b1	Clear the EDSCR.PipeAdv bit to 0.

CSE, bit [2]

Clear Sticky Error. Used to clear the EDSCR cumulative error bits to 0. The actions on writing to this bit are:

CSE	Meaning
0b0	No action.
0b1	Clear the EDSCR.{TXU, RXO, ERR} bits, and, if the PE is in Debug state, the EDSCR.ITO bit, to 0.

Bits [1:0]

Reserved, RES0.

Accessing EDRCR

EDRCR can be accessed through the external debug interface:

Component	Offset	Instance
Debug	0x090	EDRCR

Accessible as follows:

When DoubleLockStatus(), or !IsCorePowered(), or OSLockStatus(), accesses to this register generate an error response.
When SoftwareLockStatus(), accesses to this register are WI.
Otherwise, accesses to this register are WO.

21/03/2025 17:53; 154105dd5041532b480d9ef0c018b8420cbe5c19