Step signals for Z motor (1 reply)

I was viewing the step signals of Z motor on an oscilloscope and found that the signals were just of a 10 percent duty cycle and were very less in number compared to what the required steps per mm demanded. Anybody can guide me on where to look for the step signal generation source code of Marlin as I'd like to understand the logic behind it? I have gone through the header files in Marlin but I'm not able to grasp it.
Thanks in advance!