At 09:22 AM 3/31/2005 -0800, you wrote:
> > Hi Mauricio,
> > here is a PIC in-circuit programmer that does what you want:
> >   Supports PIC16F716; Press 1 button on the programmer and the target PIC
> > gets programmed,
> > plus it is only $135 ;-)
> >
> > 
> http://microcontrollershop.com/product_info.php?cPath=112_97&products_id=814
>
>Looks good, except that it doesn't appear to do Vcc margin testing during
>verification.
>
>-- Dave Tweed

Dave,
this programmer is either powered from its own internal 5V supply or uses 
the target boards
Vcc voltage. Verification is always done at the voltage selected.

To do Vcc margin testing would require to use the target board Vcc,
program and verify the chip at let's say the high margin voltage (by 
powering target board at high margin voltage),
then switch the board's voltage to the low margin voltage and do a second 
verify.

This of course defeats the one-button-push programming, as the second 
verify would have to be done via the PC
software interface.

In 90+% of applications however the PIC is powered by a voltage regulator, 
which means it always
runs at a single fixed voltage (+-10%). In those cases I would question the 
need to do a verify at both
the min and max Vcc of the chip. IMHO this is only required if your 
application uses the PIC over a wide voltage range.

best regards
Volker
MicroController Pros Corporation
The MicroController and Embedded Systems Tool Store
http://microcontrollershop.com
+1-408-333-9266 Phone
+1-800-510-3609 Toll-free phone
+1-215-243-6071 Fax 
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