Lpc2000

--- In lpc2000@yahoogroups.com, "jayasooriah" <jayasooriah@y...> wrote:
> The response from Philips is what you would expec.  Philips is not the
> only manufacturer that produces devices with flash memory.  The other
> manufacturs do change their technology too.
> 
> Unlike Philips, they publish the programming algorithm so that we all
> can evaluate it for what it is worth.  
Not all of them do, in fact ST pops immediately to mind as one who has
done a very similar thing.  And I suspect it was for much the reason
the Philips has claimed (to keep the changes in flash technology from
having to be propagated up to the user).  They got bit by that once.

Philips left out an obvious and related reason.  By keeping the flash
algorithm hidden in an internal state machine they reduce the
inevitable support cost associated with exposing it.  

In some sense I haven't seen a flash in quite some time that had it's
programming algorithm exposed.  The last one I saw was probably in the
early to mid 90's. Even the external ones hide it behind an internal
state machine.  NAND flash on the other hand I don't know about.


I can understand your security concerns even if I don't share them but
your angst over them not exposing the flash programming algorithm
seems to be overdone.  That the programming section is somewhat
vulnerable is unfortunate even if you are one of very few people who
have reported a problem with it, but it is no worse than any micro
with no built-in isp algorithm.  ISP support is, after all, a fairly
recent innovation.  I still know of systems where development testing
is done by unsocketing an EPROM and placing under a UV lamp while
replacing it with a newly programmed replacement.

Better protection of that boot block is desireable, but if Philips is
really moving that into ROM as has been suggested then that is already
happening.

Advertising what is essentially a 120K device as a 128K device is
another question, but it is unfortuately the sort of specmanship I've
come to expect from semiconductor companies.

RTFM and caveat emptor

Robert