3.5.1. Debug request output wiring
When the trigger condition occurs, you can set the ETM7 to
assert DBGRQ until DBGACK is observed under the control
of bit 9 in the ETM control register.
Note
ARM7 processors take at least one cycle to respond to DBGRQ. This means that the ARM processor
can execute a few instructions after the trigger condition is detected
but before the system has stopped. Some debug tools can report an
unrecognized breakpoint as a result.
It is recommended that you connect the DBGRQ output
of the ETM7 to the DBGRQ input
of the ARM processor. If this input is already in use, for example
a DBGRQ input is present on the
device, the DBGRQ signals can
be ORed together as shown in Figure 3.11.
PDF version