GPTM timer interval load value when up counting

Experience teaches that this "up count" (appears) easier.   (simply increment until the "match value" is reached.)

Timer's implementation adds complications.

So - perhaps a "wide timer" "loaded w/a value higher than ever expected to see use" (max_val) - and configured to "count down" UNTIL:

(max_val - "computed" interval_load_val = desired duration) enables the (simpler) down-count while (likely) avoiding the compication wrought by the prescaler.

Trick here is to pre-load the Timer w/a value which will never over-flow - and then subtract from that (high value) the number of timer ticks which equals the desired timer duration.   That calculated value - when reached - signals "timer match."   (different ARM MCUs are better suited to accommodate this method - I'm unsure about those here...)

Thinking about this bit more - the switch to "Wide Timer" and then the simple load of the Timer Start Register with a value equal to timer duration (system clock * timer ticks) should generate the Timer Interrupt when that timer's "Down Count" is exhausted.   (reaches zero)

No pre-scalers (and their complications/management) are required via this method.

Whether counting up - or counting down - use of the wide timer enables the SAME "timer tick" value to be employed. (thus removes the (seeming) advantage (directness) of the count-up method...)