Andy Warren wrote:-

     
    >I have four suggestions, Tom:
     
    >1.  Make sure that the Oscillator Type is set to HS (High Speed). 
    >2.  ONLY put the scope on Pin 15 (OSCOUT); unless you have a very
        high-impedance probe, putting it on Pin 16 (OSCIN) will load 
        down the oscillator and can stop the clock.  Note that the 
        frequency on OSCOUT is OSCIN/4, so don't be surprised if you 
        see "only" 5 MHz on that pin.
    I thought OSCOUT was OSCIN/4 only for RC not crystals. Also probing OSCOUT 
    can stop the clock or alter the frequency, unless it is high impedance, low 
    capacitance.
    
    >3.  Check Vdd and Vss, and make sure the oscillator caps are tied
        to Vss, not Vdd.
    Does connecting osc caps to vdd affect the clock? (as long as the supply is 
    decoupled well, I've not *yet* had a problem)
    
    >4.  With the crystal, try using smaller caps (15 pF instead of 33
        pF).  With the ceramic resonator with built-in caps, make 
        sure that those internal caps are in the 10 pF range.
     
     Yep, 15 or 18pf, not 33pf
    Hope this helps...
     
    -Andy
     
=== Andrew Warren - fastfwd@ix.netcom.com
=== Fast Forward Engineering, Vista, California 
=== http://www.geocities.com/SiliconValley/2499