1) Does anyone know a source of a programming adapter suitable for an
18LF8620 (80pin TQFP 0.5mm pitch) preferably suitable for use with a PS+
(i.e. 40PIN DIP)?

2) I am having a nightmare trying to program the above devices using ICSP.
I have been trying a Promate2 (with MPLAB 5.74 and MPLAB 6.30) and an ICD2
(with MPLAB 6.30) and the results with both are the same.  The PIC has to
run at 3.3 volts, and the power is shared by many devices that are not 5v
tolerant.

With a brand new PIC, if I perform a blank check, the programmer (either of
them) reports that the device is not blank.  Specificaly, the program memory
always has the same pattern in memory starting with 0xC0C0 at address
0x0000.  If I try to erase the PIC at 3.3volts, it fails to erase the
program memory, but the PROMATE then reports that the configuration fuses
are clear.  This is exactly the opposite to what logic dictates as the
datasheet states that the configuration fuses can only be cleared by a bulk
erase at >=4.5volts.  In any case, the PIC fails to program.

After pulling my hair out for a day, I stared lifting the Vdd pins on the
PIC so that I could power it from an external 4.5volt supply and perform a
bulk erase.  After this, the PIC will program happily at 3.3 volts.
However, this is really not practical as a) I have a stack of boards that
all exhibit this problem, and b) the PCB is made from a material suitable
for high frequency use and the copper delaminates very easily compared to
FR4.

In the (recent) past I have seen a simmilar issue with a few other 18F
series PIC's, notably 18LF452 and 18LF6620. However, it was only the
occaisional device and I was able to apply 4.5 volts without causing damage
to other components in those cases.

Has anyone else seen this, and does anyone have any suggestions as to what
to try next? (Microchip has been contacted, but deadlines are looming!)

Regards

Mike


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