First we select the Basic application as Waveform timing and Timing mode as Period, frequency . We set the Signal input to Aux_CNT0 and inv(ert) the signal, so it is normally low; we can also set the signal Input filter to prevent glitches .

Then there is one additional field to tell the software what to do when no new value is available. The new value is calculated only when a signal changes the value from low to high. Therefore the value can't be calculated most of the time. If we choose to repeat the last value, then the same value will be added until a new transition is made. Alternately, we can select to output zero value when no new value is available, so we will have only spikes at the points of new data and the rest of data the value will be zero .

Channel setup

The example below shows how the measurement is performed. The two white cursors in the recorder show the time difference of the two pulses (it is shown on the left on the recorder setup screen ). It reads 1.529 seconds. The counter value is of course much more exact, as it shows 1524.002 . Since the counters are running with a 80 MHz clock, we have below a microsecond resolution. Out of the period, the counter also calculates a frequency, which is simple 1/period. We can set the units of period values and frequency in the channel list on the setup screen.

Analysis - Period measurement