Conditions for Starting/Stopping Triggers

In the HCS08 target, A and B are two address comparators referred as triggers that make one big trigger. The trace collection starts or ends depending on the From or Until trigger selected along with a combination of actions involving A and B.

Both the triggers, A and B, perform the same action depending on the option selected from the Trace Start/Stop Conditions group. If you select the Collect Trace From Trigger option, both A and B are used for starting the trace collection. If you select the Collect Trace Until Trigger option, both A and B are used for stopping the trace collection.

If From trigger is selected, the application activates the trace when conditions A and B are met and starts collecting the trace data.

If Until trigger is selected, the application starts collecting trace and stops when conditions for A and B are met.

For the following trigger modes, trace starts from the triggered address rather than from the first address in the trace buffer.

For the following trigger modes, the trigger address cannot be determined. Therefore, trace starts from the first entry in the trace buffer.

Note: For more information on trigger modes, refer Table 1.
Warning: If you are setting breakpoints with triggers for trace control in the HCS08 target, ensure that you do not to use more than one breakpoint. This is because on HCS08, two hardware debug modules, BDC (Background debug controller) and DBG (debug module) are used. Both debug modules can be used for setting hardware breakpoints, while only DBG can be used for setting triggers. The first breakpoint is set using BDC, any other breakpoints will use DBG and will conflict with the triggers. Therefore, it is mandatory not to use more than one breakpoint when setting triggers on the HCS08 platform.