(One last somewhat general question)

If I'm using an external 20Mhz oscillator connected to the CLKIN/CLKOUT pins (RA5 & RA4, respectively) should I set their TRISA value to 1? Right now I have this:

Code:
TRISA    = %00000011     ' Make PortA pins 0-1 input for rotary encoder
Should that be:

Code:
TRISA    = %00011011     ' Make PortA pins 0-1 input for rotary encoder, 4-5 for external oscillator