Debug
ARM DDI 0388I
Copyright © 2008-2012 ARM. All rights reserved.
10-11
ID073015
Non-Confidential
The watchpoint value contained in the WVR always corresponds to a
Data Virtual Address
(DVA) and can be set either on:
•
a DVA
•
a DVA and context ID pair.
For a DVA and context ID pair, a WRP and a BRPs with context ID comparison capability must
be linked. A debug event is generated when both the DVA and the context ID pair match
simultaneously.
shows how the bit values correspond with the Watchpoint Value
Registers functions.
10.5.4
Watchpoint Control Registers
The WCRs contain the necessary control bits for setting:
•
watchpoints
•
linked watchpoints.
shows the WCRs bit assignments.
Figure 10-4 WCR Register bit assignments
shows the WCRs bit assignments.
Table 10-7 Watchpoint Value Registers bit functions
Bits
Name
Description
[31:2]
-
Watchpoint address
[1:0]
-
RAZ on reads, SBZP on writes
Reserved
Linked BRP
L/S
W
Reserved
Watchpoint
address mask
31
21 20 19
16 15
5
3 2
1
E
SP
24
4
0
14 13
29 28
23
Secure state access control
12
RAZ,SBZP on writes
8
9
Reserved
Byte
address
select
Table 10-8 WCR Register bit assignments
Bits
Name
Description
[31:29]
-
RAZ on reads, SBZP on writes.
[28:24]
Watchpoint
address
mask
Watchpoint address mask.
[23:21]
-
RAZ on reads, SBZP on writes.
[20]
E
Enable linking bit:
0
Linking disabled.
1
Linking enabled.
When this bit is set, this watchpoint is linked with the context ID holding BRP selected by the linked BRP
field.
[19:16]
Linked
BRP
Linked BRP number. The binary number encoded here indicates a context ID holding BRP to link this WRP
with. If this WRP is linked to a BRP that is not configured for linked context ID matching, it is
UNPREDICTABLE
whether a watchpoint debug event is generated.