Another odd thing that can happen is, if there is no power to the chip=20
but some inputs are high, the chip will be powered through the=20
protection diodes of the inputs.  As conditions change (inputs go high=20
or low) the power to the chip changes.

Kerry


Barry Gershenfeld wrote:
> The "slowly decreasing" statement reminds me of times when I thought I wa=
s
> connected to ground, but wasn't.  So make sure that besides all the verif=
ied
> grounds you also verify the ground to the scope and the power supply, and
> the debugger.
>
> Otherwise it kinda sounds like the supply voltage is sagging.  You didn't
> say what you're debugging with, but the ICD's have a "power from
> target/power from debugger" choice.  And don't ask me how I know, but the
> power has to actually be turned on.  Putting in more capacitors gives it
> more opportunity to "charge up" off of stray supply sources and then work
> for a few milliseconds.
>
> I've never hurt an ICD, but I have sent PM3's back to the factory on two
> occasions for losing their ability to power the target.
>
> Barry
>
>
> ...When looking at the PGC and PGD data during a connect, it seems like
>  =20
>> there is some
>> capacitance between the signal lines and ground.  Both the clock and dat=
a
>> signals
>> slowly decrease in voltage magnitude throughout an attempted
>> connection/program
>> operation to the PIC.  I added decoupling capacitors between power and
>> ground, which
>> temporarily fixed the problem....
>>
>>    =20



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