Yes, but there is a good workaround...Just read in the program words you
want to keep and re-write them. Similar situation on the PICF24 and DsPIC.

--Bob

> I started working on a bootstrap for the PIC18F44J10, and was surprised
> to find that the size of a block erase is 1024 bytes.  The datasheet
> says that the block erase is required for at least every third write
> which makes me think I have to use it rather than writing a block of all
> FFFF to a 64 byte flash write block to do a pseudo erase.  The problem I
> have with that is that if I want to maintain memory on the part that is
> never erased, the size of that memory must be at least 1K.  So, if I
> want to have the boot block at the start of memory to encompass the
> reset and interrupt vectors, that's 1K of codespace that I can't erase
> at the start, and in addition, if I want to maintain the configuration
> bytes at the end of program memory, that's another 1K of code that I
> don't want to ever erase.  That leaves me with only 14K of usable code
> space for the part.  I can live with that for my current application,
> but it seems pretty wasteful.  Am I not thinking about this correctly?
> Will a 64 byte block write of all 1's effectively substitute for a cell
> erase?  I've looked at the App note 851, and although it claims to apply
> to all PIC18F devices, it was released in 2002, and refers to
> configuration bytes in different memory spaces so I don't think it
> covers this part.
>
> Thanks,
>
> Tony
>
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