12.6.3. Behavior of the processor on debug events

This section describes how the processor behaves on debug events while not in debug state. See Debug state for information on how the processor behaves while in debug state. When the processor is in Monitor debug-mode, Prefetch Abort and Data Abort vector catch debug events are ignored. All other software debug events generate a debug exception such as Data Abort for watchpoints, and Prefetch Abort for anything else.

When debug is disabled, the BKPT instruction generates a debug exception, Prefetch Abort. All other software debug events are ignored.

When DBGENm is LOW, debug is disabled regardless of the value of DBGDSCR[15:14].

Table 12.38 shows the behavior of the processor on debug events.

Table 12.38. Processor behavior on debug events

DBGENmDBGDSCR[15:14]Debug mode

Action on software debug event

Action on halting debug event

0bxxDebug disabledIgnore or Prefetch Abort (for BKPT)Ignore
1b00NoneIgnore or Prefetch Abort (for BKPT)Debug state entry
1bx1HaltingDebug state entryDebug state entry
1b10MonitorDebug exceptionDebug state entry

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