PIC EC question

You really should state which PIC you are talking about.  Anyway, in the
PICs that I use, the answer is no.  The datasheet is very clear for
these models that the other OSC pin is an I/O pin when EC mode is
selected.

It is not clear. If Fosc/4 is available in RC mode, one presumes these
transistors do not disappear in EC mode. Would it kill them to
explicitely state that the Fosc/4 available in the other mode is or is
not availble in EC mode? What a weird mess of features these PICs
have...
"Here's something useful but it only works in crappy RC mode. If you
use the better EC mode, we'll let you guess if the feature still works."

Here is a cut/paste from the 12F683 datasheet:

3.3.2 EC MODE
The External Clock (EC) mode allows an externally
generated logic level as the system clock source.
When operating in this mode, an external clock source
is connected to the OSC1 pin and the GP5 pin is
available for general purpose I/O. Figure 3-2 shows the
pin connections for EC mode.

I don't know how much more clear they could have made it.  OSC2 is an
I/O pin in EC mode.


works."

Maybe you could use the INTRC with the CLKOUT feature, but I still don't
know what PIC model you are using.