I believe KhaledOsmani might have misinterpreted your request (or I did). His answer will work if you are using a crystal with the internal oscillator circuit of the PIC16F630. If I read your question correctly, you want to connect an external oscillator where the clock is generated outside of the PIC. If that is the case, connect the clock output to the CLKIN (pin 2) of the PIC.
You will need to set the configuration bits to define what clock source you are using. How you do it will depend on your compiler. Read your manual to find out how to do it.
For an external oscillator as I described, you need to set:
Code:
// EC: I/O function on RA4/OSC2/CLKOUT pin, CLKIN on RA5/OSC1/CLKIN
#define FOSC_EC 0xFFFB
If your are using a crystal as KhaledOsmani described, use:
Code:
// HS oscillator: High speed crystal/resonator on RA4/OSC2/CLKOUT and RA5/OSC1/CLKIN
#define FOSC_HS 0xFFFA
// XT oscillator: Crystal/resonator on RA4/OSC2/CLKOUT and RA5/OSC1/CLKIN
#define FOSC_XT 0xFFF9
// LP oscillator: Low power crystal on RA4/OSC2/CLKOUT and RA5/OSC1/CLKIN
#define FOSC_LP 0xFFF8
Which one you use will depend on the type of crystal you use so consult the data sheet.
The names of the configuration bits I listed are from HiTech C. Yours may be different. In either case, you need to configure the clock source or the PIC will not function as expected (if at all).