STM32VL Discovery Input Capture Mode

Enable the interrupt when you get the button press, disable it once you have the measurements you need.

Good approach indeed, thank you for reply. But, I've been thinking if i get just one result. When I press the button, I will get the results along few miliseconds more or less. Is it possible that I get only one result at rising edge of trigger?

I'd honestly think you'd need multiple measurements, not least for the reason that you don't know if the button push is coherent with the input signal. The latency to getting a good measurement will depend on the frequency of the signal you are attempting to measure.

I understand. That's very helpful, thank you.