Debug
ARM DDI 0363G Copyright © 2006-2011 ARM Limited. All rights reserved. 12-27
ID073015 Non-Confidential
12.4.14 Watchpoint Value Registers
Each DBGDSWVR is associated with a Watchpoint Control Register (DBGWCR). DBGWCRy
is the corresponding register for WVRy.
A pair of watchpoint registers, DBGWVRy and DBGWCRy, is called a Watchpoint Register
Pair (WRP). DBGWVR0-7 are paired with DBGWCR0-7 to make WRP0-7.
The watchpoint value contained in the DBGDSWVR always corresponds to a data address and
can be set either on:
• a data address
• a data address and context ID pair.
For a data address and context ID pair, a WRP and a BRP with context ID comparison capability
must be linked. A debug event is generated when both the data address and the context ID pair
match simultaneously.
Table 12-18 Meaning of DBGBVR bits [22:20]
DBGBVR[2
2:20]
Meaning
b000 The corresponding DBGBVR[31:2] is compared against the instruction address bus and the state of the
processor against this DBGBCR. It generates a breakpoint debug event on a joint instruction address and
state match.
b001 The corresponding DBGBVR[31:2] is compared against the instruction address bus and the state of the
processor against this DBGBCR. This BRP is linked with the one indicated by DBGBCR[19:16] linked
BRP field. They generate a breakpoint debug event on a joint instruction address, context ID, and state
match.
b010 The corresponding DBGBVR[31:0] is compared against CP15 Context ID Register, c13 and the state of
the processor against this DBGBCR. This BRP is not linked with any other one. It generates a breakpoint
debug event on a joint context ID and state match. For this BRP, DBGBCR[8:5] must be set to b1111.
Otherwise it is Unpredictable whether a breakpoint debug event is generated.
b011 The corresponding DBGBVR[31:0] is compared against CP15 Context ID Register, c13. This BRP links
another BRP (of the DBGBCR[21:20]=b01 type), or WRP (with DBGWCR[20]=b1). They generate a
breakpoint or watchpoint debug event on a joint instruction address or data address and context ID match.
For this BRP, DBGBCR[8:5] must be set to b1111, DBGBCR[15:14] must be set to b00, and
DBGBCR[2:1] must be set to b11. Otherwise it is Unpredictable whether a breakpoint debug event is
generated.
b100 The corresponding DBGBVR[31:2] and DBGBCR[8:5] are compared against the instruction address bus
and the state of the processor against this DBGBCR. It generates a breakpoint debug event on a joint
instruction address mismatch and state match.
b101 The corresponding DBGBVR[31:2] and DBGBCR[8:5] are compared against the instruction address bus
and the state of the processor against this DBGBCR. This BRP is linked with the one indicated by
DBGBCR[19:16] linked BRP field. It generates a breakpoint debug event on a joint instruction address
mismatch, state and context ID match.
b11x Reserved. The behavior is Unpredictable.
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