A.2.1. Invasive debug

This section describes the invasive debug features that are available:

Debug events

All software debug events are supported, that is, BKPT instruction, breakpoints, watchpoints and vector catch.

Only one halting debug event is currently handled. External debug request is triggered by means of the signal port edgrq. The halting debug events, Halt Request and OS Unlock Catch are not currently implemented.

The external signal port is not connected in the VE platform.

Debug exceptions

Monitor debug mode is available in the AEM when configured through the DBGDSCR. In this mode software debug events cause a debug exception resulting in either:

  • a pre-fetch abort exception in the case of a BKPT instruction event, breakpoint event and vector catch event

  • a data abort exception in the case of a watchpoint event.

Debug state

You can configure the AEM to enter debug state in the case of a software debug event through the DBGDCSR. Halting debug events always enter debug state if debug is both enabled and permitted.

Invasive debug authentication

Debug is enabled or disabled by two signals on the external debug interface, dbgen and spiden. Signal ports for non-invasive debug, niden and spniden, are present but are currently unused.

The external signal interface is not connected in the VE platform.

Copyright © 2008-2013 ARM. All rights reserved.ARM DUI 0423O
Non-ConfidentialID060613