Digitally controlled oscillator (DCO) design help required.

I guess TH = Time High, and TL = Time Low.
If you add the two values together you get the period.

JimB

I have a question regarding the design of the OP's DCO. What equation is used to determine the speed in which the feedback capacitor C1 is discharged from its maximum amplitude back to 0V (or near)? Since the RC time constant is chosen on this basis. I have simulated a similar design ans it is in the region of 5us., but how can this be shown?