EDITR, External Debug Instruction Transfer Register

The EDITR characteristics are:

Purpose

Used in Debug state for passing instructions to the PE for execution.

Configuration

EDITR is in the Core power domain.

Attributes

EDITR is a 32-bit register.

Field descriptions

The EDITR bit assignments are:

When AArch32 is supported at any Exception level and in AArch32 state:

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
T32Second																T32First

T32Second, bits [31:16]

Second halfword of the T32 instruction to be executed on the PE. When EDITR contains a 16-bit T32 instruction, this field is ignored. For more information, see 'Behavior in Debug state'.

T32First, bits [15:0]

First halfword of the T32 instruction to be executed on the PE.

When AArch64 is supported at any Exception level and in AArch64 state:

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
A64 instruction to be executed on the PE

Bits [31:0]

A64 instruction to be executed on the PE.

Accessing the EDITR

If EDSCR.ITE == 0 when the PE exits Debug state on receiving a Restart request trigger event, the behavior of any instruction issued through the ITR in Normal access mode that has not completed execution is CONSTRAINED UNPREDICTABLE, and must do one of the following:

• It must complete execution in Debug state before the PE executes the restart sequence.
• It must complete execution in Non-debug state before the PE executes the restart sequence.
• It must be abandoned. This means that the instruction does not execute. Any registers or memory accessed by the instruction are left in an UNKNOWN state.

EDITR ignores writes if the PE is in Non-debug state.

EDITR can be accessed through the external debug interface:

This interface is accessible as follows:

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