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tcbcats
- 3rd March 2004, 05:59
I have a 16F628 that the EPIC serial programmer will not program because the LVP pin on the device is held high in my circuit.
The programmer error is "Target device does not match selected device"

If I hold it low, it programs fine.
I have included the "DEFINE LVP_OFF" but it still thinks the pic is set up for LVP ?

Is there a way to get the chip to program without holding bin B4 low?... Is there another define or cfg setting that I should use?

No problrms on other 16 or 18F chips... only the 16F628.

Thanks,
tcbcats

NavMicroSystems
- 3rd March 2004, 19:59
as far as I can remember the problem is:

on an erased (or new) chip the LVP bit is set.
the datasheet says the high voltage mode overrides the LVP-mode but this is not really true.

To program the device RB4 must either be floating or pulled low.
With a pullup on RB4 you will not be able to program a device that has the LVP-Bit set.

regards