ARM Cortex-M3 User Manual

System Debug
11-2 Copyright © 2005-2008 ARM Limited. All rights reserved. ARM DDI 0337G
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11.1 About system debug
The processor contains several system debug components that facilitate:
• low-cost debug
• trace and profiling
• breakpoints
• watchpoints
• code patching.
The system debug components are:
• Flash Patch and Breakpoint (FPB) unit to implement breakpoints and code
patches.
• Data Watchpoint and Trace (DWT) unit to implement watchpoints, trigger
resources, and system profiling.
• Instrumentation Trace Macrocell (ITM) for application-driven trace source that
supports printf style debugging.
• Embedded Trace Macrocell (ETM) for instruction trace. The processor is
supported in versions with and without the ETM.
All the debug components exist on the internal Private Peripheral Bus (PPB) and can
be accessed using privileged code.
The system debug components are optional. You can remove all of the system debug
components and have no trace or debug functionality. This means that breakpoints and
watchpoints in addition to instrumentation trace and triggers might not be supported.
Note
• For a description of the Core debug, see Chapter 10 Core Debug.

ARM Cortex-M3 Specifications

General

Architecture	ARMv7-M
Instruction Set	Thumb-2
Pipeline Stages	3-stage
Interrupts	Nested Vectored Interrupt Controller (NVIC)
Interrupt Controller	Nested Vectored Interrupt Controller (NVIC)
Memory Protection Unit	Optional
Power Consumption	Varies by implementation
Max Clock Speed	Up to 100 MHz
Debugging	JTAG and Serial Wire Debug (SWD)
Operating Voltage	1.8V to 3.6V
Manufacturing Process	Varies by implementation
Core Type	32-bit