Your question, while seemingly simple, does not provide enough information to allow a simple answer.
For starters, the one pic output you describe would, ordinarily, be controlled by some manner of code. That code would dictate the output, i.e., starting condition (0 or 1), frequency, duration, etc. That in turn would be sent to a PWM circuit to control a servo on, say, a machining bed, and so on.
I may be stating the obvious, but CNC controllers are enormously complex devices, especially if taken from CAD file design all the way to finished product.
Please elaborate on your idea.