Signal Descriptions
ARM DDI 0388I
Copyright © 2008-2012 ARM. All rights reserved.
A-25
ID073015
Non-Confidential
WPTPC[31:0]
O
PTM device
Waypoint last executed address indicator.
This is the base Link Register in the case of an exception.
Equal to 0 if the waypoint is a reset exception.
WPTT32LINK
O
Indicates the size of the last executed address when in Thumb state:
0
16-bit instruction.
1
32-bit instruction.
WPTTAKEN
O
The waypoint passed its condition codes. The address is still used,
irrespective of the value of this signal.
Must be set for all waypoints except branch.
WPTTARGETJBIT
O
J bit for waypoint destination.
WPTTARGETPC[31:0]
O
Waypoint target address.
Bit [1] must be zero if the T bit is zero.
Bit [0] must be zero if the J bit is zero.
The value is zero if
WPTTYPE
is either prohibited or debug.
WPTTARGETTBIT
O
T bit for waypoint destination.
WPTTRACEPROHIBITED
O
PTM device
Trace is prohibited for the waypoint target.
Indicates entry to prohibited region. No more waypoints are traced until
trace can resume.
This signal must be permanently asserted if
NIDEN
and
DBGEN
are both
LOW, after the in-flight waypoints have exited the processor. Either an
exception or a serial branch is required to ensure that changes to the inputs
have been sampled.
Only one
WPTVALID
cycle must be seen with
WPTTRACEPROHIBITED
set.
Trace stops with this waypoint and the next waypoint is an Isync packet.
See the
CoreSight PTM Architecture Specification
for a description of the
packets used in trace.
WPTTYPE[2:0]
O
Waypoint type.
b000
Direct branch.
b001
Indirect branch.
b010
Exception.
b011
DMB, DSB, ISB.
b100
Debug entry.
b101
Debug exit.
b110
Invalid.
b111
Invalid.
Debug Entry must be followed by Debug Exit.
Note
Debug exit does not reflect the execution of an instruction.
Table A-29 PTM interface signals (continued)
Name
I/O
Source or
destination
Description