>From my experience with 12F629/675, erased it first by
ERASE command and then use the WRITE command does help 
in the cases. I guess it is really less demanding. 
Still it needs to read the device ID bits and then
preserve the bandgap bits (within the configuration
word) and the OSCCAL value. So I am also not so sure
why the ERASE command can do the trick in my test
cases. Without the ERASE command first, test of xwisp2
using 12F629/675 with INTOSC and internal /MCLR
will fail.

Regards,
Xiaofan

-----Original Message-----
From: Jan-Erik Soderholm
Sent: Wednesday, September 21, 2005 4:07 PM
To: piclist@mit.edu
Subject: RE: [PIC] Trouble programming 16LF648A using Wisp628

I don't follow here...

*If* you have chip that has problem with re-programmiong if
int-MCLR is enabled (like the 12F629/675), I don't see how it
can be erased, since you have to be able to put the chip in
"programming mode" no matter what you'd like to do with it, not ?

Or is an "erase-only" operation less demanding on the access to
the chip ? Such as that you don't have to read the device ID bits
(or something) ?


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