At 12:01 PM 6/15/04 -0400, you wrote:
>> >Subject: Re: [PIC] PIC18F452 LVP pin needs to be tied low?>
>> >
>> >LVP on! As I said above I'm clear on the LVP pin problem when
>> >programming. So the new wrinkle is ICSP. Even when doing HVP
>> >only via ICSP one must make sure that the LVP pin doesn't float.

This thread has interested me because I have a board that leaves RB.5
floating (unconnected). And it has always worked correctly with ICSP.  So
have I just been lucky?

Answer: no. I think! :)

A quick experiment was performed. On my '252 board, I soldered a 2.2K
resistor from RB.5 to +5 volts.   If a pin floating high is a problem, then
this ought to find it.

Then I erased the part via ICSP using the ICD2.  Blank check showed erased
part.  Then I programmed it.

Result: no problem.  Board works fine.

It is possible that different programmers might work differently in this
regard, I don't know. But for the ICD2, there seems to be no problem with
RB.5 floating high.

Comments invited.
Tom

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