Can I do in-circuit programming with my PICWriter?

Submitted by: TechTools

Yes, but...

It is *POSSIBLE* to do in-circuit programming with ANY programmer if you take enough precautions.

Any programmer that is not designed for in-circuit programming, expects to be able to comtrol and power a PICmicro MCU. It does NOT expect to have any other out-side influences (loads, delays, capacitence..). Nor does it expect to have power back-fed to it.
If you make your in-circuit device LOOK like it is 'in-socket', then most any programmer will work. This often means completely isolating the devices programming related pins from the target (possibly including VCC), often making it too impractical.

Our QuickWriter, on the other hand, is DESIGNED to do in-circuit programming. It expects to see loads, delays and signal skews from the target.

It also expects the possibility of having Voltages back-fed to it. Dedicated circuitry monitors for faults and interlocks the programming timimg with the target signal delays and skews.

QuickWriter makes in-circuit programming more reliable, more fault tolerant and less demanding on the target design.

Regardless of which programmer you use, our 'In-circuit Programming with QuickWriter' is worth reviewing. Search for 'ICP' on our web pages.