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 DBGEN is LOW, debug is disabled regardless of the value of DSCR[15:14].

Table 12.52 shows the behavior of the processor on debug events.

Table 12.52. Processor behavior on debug events

DBGENDSCR[15:14]Debug modeAction on software debug eventAction on halting debug event
0bxxDebug disabledIgnore or Prefetch Abort[1]Ignore
1b00NoneIgnore or Prefetch AbortaDebug state entry
1bx1HaltingDebug state entryDebug state entry
1b10MonitorDebug exception or Ignore[2]Debug state entry

[1] The BKPT instruction generates a Prefetch Abort. All other software debug events are ignored.

[2] Prefetch Abort and Data Abort vector catch debug events are ignored in Monitor debug-mode. All other software debug events generate a debug exception.


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