I wanted to find the capacitance at X,Y,P and Q in the diagram given below. Idea was to find the dynamic power consumption of the circuit and for that we need the capacitance(I got this idea from a IEEE paper 'StrongARM Latch'). Is there any method to get the capacitance using simulation and also get the capacitance using some formula or calculation? I know the dimension of the transistors used. It would be great if you can suggest a method that I could use for this circuit as well as any general circuit. I am sorry if the question is vague, please lemme know if any more information is needed.
Capacitance, like voltage, is not defined "at a point"; it is defined between two points.
In a VLSI circuit the capacitances include parasitic capacitances to all of the surrounding structures as well as junction capacitances and gate capacitances. Some of these vary with applied voltage.
The right way to do this is to create an actual layout and use your design tools to extract the capacitances for each node.