Thanks ALL who replied.
I do use capacitors in the schematic.
Please see the schematic here
http://www.dilynamobily.cz/Media/Uploaded/Normal/Problem.jpg
( the link is case sensitive)

My problem is that I can not debug any program using PIC16f648A - ICD=20

Please check and let me  know if you can see any problem
Thanks
L.


> OK, whatever.
>=20
> We don't know for sure if there are any capacitors or not.
> And if not, isn't it a possible "problem" ?
> I think it is.
>=20
>=20
> jim wrote 2011-11-05 14:53:
> >
> > The main reason for the capacitors in a crystal circuit is to provide a=
n
> > intentional imbalance between the input of the oscillator and output pi=
n of
> > the oscillator so that when power is applied, the imbalance causess cur=
rent
> > to flow, and thereby guarantees the oscillator will start oscillating.
> >
> > Jim
> >
> > -----Original Message-----
> > From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behal=
f Of
> > Isaac Marino Bavaresco
> > Sent: Saturday, November 05, 2011 7:45 AM
> > To: Microcontroller discussion list - Public.
> > Subject: Re: [PIC] IS this faulty?
> >
> > Em 5/11/2011 10:57, Jan-Erik Soderholm escreveu:
> >>>> I *think* that the header is useless without a target circuit.
> >>> But what is the smallest target circuit?I thought adding only crystal=
 is
> >>> OK for starting debugging
> >> Right, but a crystal is useless without capacitors. And it is
> >> a bit unclear how the header is powered.
> >
> >
> > Not exactly. It may become unstable, or not to oscillate at all, but it=
 may.
> >
> >
> >>> Sorry, I have just only  started with microchips  - so a lot  of new
> >>> knowledge for me to learn.
> >> It's not about learing PICs, it's about telling everything and
> >> not hiding details. :-)
> >
> >
> > By my experience with teaching newbies in electronics and
> > microcontrollers, it takes time to notice that there's missing informat=
ion.
> > Because of this, I generally take it easy with them.
> >
> >
> > Isaac
> >
> --=20
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist


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