peter green wrote:

> Taking a chip with LVP disabled into program mode,
 > bulk erasing it (which enables LVP) and reprogramming
 > it (disabling LVP again) seems to work fine with PGM
 > floating even if the programers VPP rise time is slow,
 > you just don't want to leave program mode while LVP
 > is enabled.

Right, if you do not cycle Vpp betweem the erase and
the re-porgramming, there should not be any problem
LVP floating. This might to a great degree depend
on the internal arhitecure in the programming
software. It would probably be simpler to make
the erase drop Vpp at the end and to have the programming
logic to raise Vpp in the beginning so that each routine
could be run alone. In that case you'd better keep
LVP low between the erase and the re-programming phases.

Jan-Erik.

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