On 8/16/06, Steve Smith <xygax@blueyonder.co.uk> wrote:
>
> Guys;
> Probably a stupid q

Not stupid at all. Been there.

> With an F629 using ICD2 I have programmed it to use mclr internal. Can you
> reprogram it ?? (haven't tried yet )

Quite possible you will not be able to do it if you use internal MCLR and
internal RC oscillator.

I ended up using a PICKit 1 and later a Promate III when I was using 12F629
for a project. PICkit 2 is a better choice now.

***********************************
>From MPLAB Help:
ICDWarn0033: You have selected Internal MCLR and Internal Oscillator
in your configuration settings. If your code makes use of port pins
that correspond to Clock and Data pins in programming mode, you may
not be able to reprogram your device. See on-line help for this
warning for more information. (OK/Cancel)

When Internal MCLR is used with MPLAB ICD 2 for programming, both Vpp
and Vdd are powered together, and then Vpp is pulled high to Vihh to
enter programming mode. This means that your code will be running
before Vpp goes to Vihh. If that code makes use of port pins that
correspond to Clock and Data pins in programming mode, there is a
chance their values may not be 0, as necessary to enter programming
mode. Therefore, the device could not be reprogrammed.

Click OK to continue programming or click Cancel to cancel the
programming operation.

Work-Around

When External MCLR is used, this is not a problem, as Vpp can go
directly to Vihh. Also, if External Oscillator is used, the external
oscillator can be kept from running, thus keeping the code from
running, until Vpp is at Vihh.

***********************************************

The real walk-around is not to use ICD2 for 12F629 programming.

Regards,
Xiaofan
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