Crystal osc running but PIC not using it

[p15218]

I'm trying to use the PBP Count function with a bit more stability than the 16F690's internal RC oscillator provides.

My problem is that I have the crystal oscillator running with the following edit to 16f690.inc file:
; __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_ON & _CP_OFF ------- original code
__config _HS_OSC & _WDT_ON & _MCLRE_ON & _CP_OFF --------my edit

BUT it matters not if I remove or short the crystal, the code still runs!
I've checked the 4 MHz crystal's pins with a scope & counter and it is active at about 3999990 Hz, close enough to 4 MHz for me.
MCLR is pulled high with a 4.7k Ohm resistor.

What else do I have to do to enable the crystal oscillator internal to the PIC ?
thanks
Bob

[Charles Linquis]

Your problem lies with the line

__config _INTRC_OSC_NOCLKOUT

The "_INTC_OSC" part means to use the internal oscillator.

You should change this to "_XT_OSC" instead

[p15218]

Your problem lies with the line

__config _INTRC_OSC_NOCLKOUT

The "_INTC_OSC" part means to use the internal oscillator.

You should change this to "_XT_OSC" instead

Well thanks but I did...notice the ";" commenting the "_INTC_OSC" line out.
Changing to "_XT_OSC" has activity at the crystal as well as _HS_OSC did with the same result that pulling the crystal makes no difference, the code runs no matter.

[Darrel Taylor]

Make sure your programmer is updating the CONFIG settings of the chip.
Usually there's an option for that.

It may still be using the CONFIG settings from a previous program.
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[Archangel]

Hi Bob,
This particular PIC has special Oscillator, options and Has FSCM, which stands for Fail Safe Clock Monitor - datasheet page 49 of 294 and as I understand it, it automaticly deploys an internal clock when oscillator failure occurs, pretty darn nifty feature unless you are doing what You want to . Easiest way is use a cheaper PIC.

[mister_e]

Easiest way is use a cheaper PIC.

And never learn... not for me.