OpenTDC is a Time to Digital Converter (TDC) and a Fine Delay (FD) design.

The TDC can timestamp a pulse with a precision below 1 ns, while the
FD can generate a pulse with the same precision.

TDC could be used to measure distances using time-of-flight of laser
pulses. It is also used to measure the time-of-flight of particules
in High Energy Physic experiments. A TDC could also be used in LIDAR.