Debug
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
11-4
ID021414
Non-Confidential
11.2
Debug register interfaces
The processor implements the ARMv8 Debug architecture and debug events as described in the
ARM
®
Architecture Reference Manual ARMv8, for ARMv8-A architecture profile
.
The Debug architecture defines a set of debug registers. The debug register interfaces provide
access to these registers from:
•
Software running on the processor.
•
An external debugger.
This section describes:
•
Processor interfaces
.
•
Effects of resets on debug registers
.
•
External access permissions
on page 11-5
.
11.2.1
Processor interfaces
System register access allows the processor to directly access certain debug registers. The
external debug interface, see
External debug interface
on page 11-37
, enables both external and
self-hosted debug agents to access debug registers. Access to the debug registers is partitioned
as follows:
Debug registers
This function is system register based and memory-mapped. You can access the
debug register map using the APB slave port. See
External debug interface
on
page 11-37
.
Performance monitor
This function is system register based and memory-mapped. You can access the
performance monitor registers using the APB slave port. See
External debug
interface
on page 11-37
.
Trace registers
This function is memory-mapped. See
External debug interface
on page 11-37
.
Cross Trigger Interface registers
This function is debug register based and memory-mapped. See
Chapter 14
Cross
Trigger
.
11.2.2
Effects of resets on debug registers
The processor has the following reset signals that affect the debug registers:
nCPUPORESET
This signal initializes the processor logic, including the debug,
Embedded Trace
Macrocell
(ETM) trace unit, breakpoint, watchpoint logic, and performance
monitors logic. This maps to a cold reset that covers reset of the processor logic
and the integrated debug functionality.
nCORERESET
This signal resets some of the debug and performance monitor logic. This maps
to a warm reset that covers reset of the processor logic.