I am not sure what you do need exactly to do. But, if you need to generate the periodic interrupt it's better to use the "TimerInt" bean. Is there any reason why you could not to use the "TimerInt" bean?
Anyway, period is the time before re-initialization of a counter. The way to tell if the interrupt is due to a Compare or an Overflow is through the "Reset Counter on Compare" property.
- If the property is set to "yes", counter is reset each time when compare matches the counter value.
(On the MC9S12C64 CPU the "yes" value is possible to set only if the the "TC7" value in the "Device" property is set.)
- If the property is set to "no", counter is reset each time when the counter overflows.
More information and an example of typical usage you can find in the "Help" of the bean. You find it in the pop-up menu of the bean.
It's also not clear which PE version do you use. However, I recommend to update to the latest version of Processor Expert (PE 2.98 for CW 4.6).