Counter Bug

Well, given this is only a snippet, the best I can do is say that the CNTR_trigger_input only goes low when counter = FF. Remember the counter will go to FF after 00 (it doesnt actuaally, go up to FF, but down).

Without the full code, thats the best I can do.

Some tips -

dont call a signal a clock when its not a clock. From your diagram it looks more like an enable or trigger (I hope its not actually clocking anything).

Whats wrong with:

if counterValue = 0 then
  CounterValue <= Reload_value;
....

Stuff like this makes code much easier to read (rather than the long list of logic inputs).