5.3.9. ThumbEE check that goes to a handler, including the CHKA instruction

If the instruction at the target of a waypoint fails a ThumbEE check, then the PTM generates an exception branch address packet, indicating the ThumbEE exception type and the address of the handler. The instruction that failed the ThumbEE check is the target of the original waypoint.

Otherwise, if an instruction fails its ThumbEE check:

  1. If the instruction before the instruction fails its ThumbEE check is not a waypoint, the PTM generates a waypoint update packet indicating the address of that instruction.

  2. The PTM generates an exception branch address packet indicating the ThumbEE exception type and the address of the handler.

The instruction that failed the check is the instruction immediately after the last waypoint instruction or promoted nonwaypoint instruction.

CHKA is not a waypoint instruction, but if a CHKA instruction causes a branch to a handler then the PTM treats this branch like an exception and:

  1. If the instruction before the branching CHKA instruction is not a waypoint, generates a waypoint update packet indicating the address of that instruction.

  2. Generates an exception branch address packet indicating a ThumbEE exception.

The PTM does not generate any trace for a CHKA instruction that does not cause a branch to a handler.

Copyright © 1999-2002, 2004-2008, 2011 ARM. All rights reserved.ARM IHI 0035B
Non-ConfidentialID060811