Regarding using the internal oscillator, I don't know right off hand,=20
but I don't see why not.   However, when developing a circuit and/or=20
software, don't change direction in the middle of an effort.  =20
In this case, keep working with the external oscillator until you get it to
work. =20
Then change oscillators.  That way, you start at a known starting point
where the=20
hardware and software already work.
If, when you change to an internal oscillator, and the circuit no longer
works,=20
you know the problem lies in that last step.  You can then work backwards t=
o
find=20
the cause.  =20

If you change in the middle of something, you don't know where you are
regarding=20
Functionality.  You have just entered another variable into the equation.
And you=20
haven't solved the first part of the problem yet.

With that said, I have added a few lines to your initial program below.
These extra=20
Lines toggle the output on and off.  The way you had it in your post, as
soon as the
Program gets to the last line, it then keeps going through memory executing
whatever is there. =20
In most cases, that will be 0x3ff, which happens to be generally speaking,
undefined. =20
However, it could be "ADDLW"

One other thing I just remembered, when using the ICD, location '0x00' has
to be a NOP.

I have added that in the code I have included here.  Although what I am
about to say goes
Against what I said above about not changing in midstream, you might want t=
o
try the code
I have included to see if it works.

Let me know what you find out.

My code snippet is...



#include "P16F628A.INC"  ; Include header file=20
;   CONFIG=3DCP_OFF & _LVP_OFF & _BOREN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE=
_ON
& _INTOSC_OSC_NOCLKOUT=20

	_CONFIG =3D 0x2170			; I like writing it this way
to save space.  But that's just me.
						; It does the same thing as
the "CONFIG" line above.
		org 0x0			; Start at location zero, not 0x10
start=09
		nop				; For ICD use, location zero
has to be a 'nop'
		movlw	0x07
		movwf	CMCON
		bsf 	STATUS,RP0		;bank1
		bcf 	TRISA,2
		bcf 	STATUS,RP0		;bank0
toggle	=09
		bsf 	PORTA,2
		call	delay			; Sets up a short (20us)
delay to give a little time between flashes
		bcf 	PORTA,2		; Added this to give more operations
to look at
		call	delay
		goto	toggle		; Causes the program to repeat the
flashing action
		goto	start
	=09
	=09
	=09
delay
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		goto	$+1
		return
			=09
	=09
		END

Regards,

Jim












-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
jana1972@centrum.cz
Sent: Saturday, November 05, 2011 12:56 PM
To: Microcontroller discussion list - Public.
Subject: RE: [PIC] IS this faulty?

Jim ,
Thank you for your reply.
But do you think that I can also use an internal oscilator instead?
I successfully programmed ( into normal PIC16F628A) this code

  #include "P16F628A.INC"  ; Include header file=20
   __CONFIG   _CP_OFF & _LVP_OFF & _BOREN_OFF & _MCLRE_ON & _WDT_OFF &=20
_PWRTE_ON & _INTOSC_OSC_NOCLKOUT=20

		org 10
		movlw	0x07
		movwf	CMCON
		bsf STATUS,RP0		;bank1
		BCF TRISA,2
		bcf STATUS,RP0		;bank0
		BSF PORTA,2
		END

As you can see it uses internal oscilator and it works in normal PIC16F628A
/ 648A
but still it does not work in PIC16F648A - ICD, no debugging possible.
Must I use external oscilator with PIC16F648A - ICD or also internal
oscilator must work?
Thanks again
L


> Let me try this again.
>=20
> PGC and PGD are RB6 and RB7 respectively.  In your schematic you show the
> PGC and PGD pins going to the OSC1 and OSC2 pins.
> This is why there is no ICD functionality with your circuit.
>=20
> If you connect the ICD pins to OSC1 and 2, you effectively disable the
> oscillator.
>=20
> Try moving the ICD PGC and PGD pins to RB6 and RB7.  You should be able t=
o
> use the ICD then.
>=20
> Regards,
>=20
> Jim
>=20
> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf
Of
> jana1972@centrum.cz
> Sent: Saturday, November 05, 2011 9:45 AM
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC] IS this faulty?
>=20
> 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)
>=20
> My problem is that I can not debug any program using PIC16f648A - ICD=20
>=20
> Please check and let me  know if you can see any problem
> Thanks
> L.
>=20
>=20
> > 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
an
> > > intentional imbalance between the input of the oscillator and output
pin
> of
> > > the oscillator so that when power is applied, the imbalance causess
> current
> > > to flow, and thereby guarantees the oscillator will start oscillating=
..
> > >
> > > Jim
> > >
> > > -----Original Message-----
> > > From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On
Behalf
> 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 ne=
w
> > >>> 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
> information.
> > > 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
>=20
>=20
> --=20
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>=20
> --=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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