the problem I have is as simple as this:
Between a given interval (e.g. 500 .. 1000mS), I have to measure an
external frequency in the range of 10..80 kcs. While the WAKE-UP Timer might do the
cyclic wakeup-job and TIMER0 might generate the timeframe for the
incoming freqency (approx. 100ms) , I still need a COUNTER to count
the incoming pulses.
My idea was to use the LFXTAL - input pin for this purpose rather than
reconfiguring the WAKE-UP Timer back and forth every interval.
Is that doable and if yes: what are the constraints of this approach?
Or: is there a way to route EXTCLK to the LFXTAL signal path?
(In the preliminary UserGuide on page 9, there is a line shown between the
functional blocks "LFXTAL" and "EXTCLK" which I can't explain.)
BTW: counting external interrupts is a NO-NO, since the system has to run
at the slowest possible FCLK.
Does anyone have an idea on how to solve that "problem"?
Thanks in advance,