7.3 Debug and Trace Support

• The Data Watchdog and Trace (DWT) unit provides four data watchpoint comparators and execution monitoring.
• The Flash Patch and Breakpoint (FPB) unit provides up to eight hardware breakpoint comparators that debuggers can use.
• Implements Embedded Trace Buffer (ETB) for execution tracing.

CoreSight ETM-M4 Technical Reference Manual – ARM DDI 0440C provides a detailed description of the ETB or ETM operation. Configuration can be done by the debugger or the CPU but the debugger must know where the trace data will be placed in RAM.