> > I'm using a low voltage programmer, so Vpp = Vdd = 5.25V.
> Is the low voltage programming enable bit set?

The LVP bit was set in the config register.

> I thought you couldn't erase code protected memory with low voltage
> programming, but I just checked the spec and found the same thing you did.
> I don't have any experience with low voltage programming.  My programmer
> always uses high voltage.

Well, as it turns out, you were right about low voltage programming being the problem.  I
converted my TLVP to a THVP with a Vpp of 11.5V and a Vdd of 5.25V.  After inverting the
MCLR pin in software to account for the circuit change, the code protected bulk erase
seemed to work perfectly in both fpp and my own programming software.

Here's some debug output from my programmer:

Config = 0x3FFF
Setting Config = 0x0000
Config = 0x0400
ID:  2EAA  1DD5  0CCC  3FB3
Starting Bulk Erase
Checking values after Bulk Erase
Config = 0x3FFF
ID:  3FFF  3FFF  3FFF  3FFF

The same sequence using the LVP programmer would only set a few bits in the config block
and wouldn't touch the ID bytes.

From this it would seem that a code protected bulk erase using a low voltage programmer
will not work in this series of PIC's, which is contrary to the datasheet.  Or maybe my
programmer wasn't all it could be...  Either way,  I would still like to hear from anyone
who has been able to perform a code protected bulk erase on the PIC16F87x series using a
low voltage on MCLR.

Thanks for the help Olin.

Sean


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