I appreciate the site author's projects very much. Regarding freq counter - elegant idea, but could not find any data on LMX2322. Also there is no source file for the processor, only hex.
What intrigues me a lot is PLL's charge pump CPo connected to the discrete RC0 PIC input. I cannot think of anything which could make this schematic to work
I would rather connect the divider output (FoLD) to the PIC's counter instead.
Also using PIC16F870 looks like overkill for this task.
Let me give some technical info about this counter.
The Counter actually use the pre-scaler inside the LMX2322.
The output is the CPo, even if it sounds odd.
The LMX2322 used in this counstruction is a 3 to 5V type.