EDHSR, External Debug Halt Status Register

The EDHSR characteristics are:

Purpose

Provides Debug Halt Status information.

Configuration

EDHSR is in the Core power domain.

This register is present only when FEAT_SME is implemented. Otherwise, direct accesses to EDHSR are RES0.

This register is only valid when the PE is in Debug state and EDSCR.STATUS is 0b101011, indicating a Watchpoint debug event. Otherwise, it has an UNKNOWN value.

The field EDDEVID1.HSR indicates support for this register.

Attributes

EDHSR is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
RES0WPTWPTVWPFFnPRES0FnVRES0

Bits [63:24]

Reserved, RES0.

WPT, bits [23:18]

Watchpoint number, 0 to 15 inclusive.

All other values are reserved.

The reset behavior of this field is:

WPTV, bit [17]

Watchpoint number Valid.

WPTVMeaning
0b0

The WPT field is invalid, and holds an UNKNOWN value.

0b1

The WPT field is valid, and holds the number of a watchpoint that triggered an entry to Debug state.

When an entry to Debug state is triggered by a watchpoint match:

The reset behavior of this field is:

WPF, bit [16]

Watchpoint might be false-positive.

WPFMeaning
0b0

The watchpoint matched the original access or set of contiguous accesses.

0b1

The watchpoint matched an access or set of contiguous accesses where the lowest accessed address was rounded down to the nearest multiple of 16 bytes and the highest accessed address was rounded up to the nearest multiple of 16 bytes minus 1, but the watchpoint might not have matched the original access or set of contiguous accesses.

The reset behavior of this field is:

FnP, bit [15]

FAR not Precise.

This field only has meaning if the EDWAR is valid; that is, when the FnV field is 0. If the FnV field is 1, the FnP field is 0.

FnPMeaning
0b0

If the FnV field is 0, the EDWAR holds the virtual address of an access or set of contiguous accesses that triggered an entry to Debug state.

0b1

The EDWAR holds any address within the smallest implemented translation granule that contains the virtual address of an access or set of contiguous accesses that triggered an entry to Debug state.

The reset behavior of this field is:

Bits [14:11]

Reserved, RES0.

FnV, bit [10]

FAR not Valid.

FnVMeaning
0b0

The EDWAR is valid, and its value is as described by the FnP field.

0b1

The EDWAR is invalid, and holds an UNKNOWN value.

The reset behavior of this field is:

Bits [9:0]

Reserved, RES0.

Accessing EDHSR

EDHSR can be accessed through the external debug interface:

ComponentOffsetInstanceRange
Debug0x038EDHSR31:0

This interface is accessible as follows:

ComponentOffsetInstanceRange
Debug0x03CEDHSR63:32

This interface is accessible as follows:


05/07/2022 17:08; b0421fa9a8865165f9b91af9b4a566111f866305

Copyright © 2010-2022 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.