Lpc2000

Hi Jaya,
I suspect that (for example) LPC2104/5/6 do use identical
dies. Devices would be sold as LPC2104 primarily because of
defects in the FLASH memory. Philips could see which / how
many banks of FLASH are usable, and (by way of undocumented
FLASH locations) tell the ARM how to configure the good
memory to appear as a particular chip. It would not surprise
me if Philips built in 10% - 20% more memory than is needed
even for an LPC2106 to allow them to swap out any blocks
which do not pass production testing.

If demand for the smaller devices picks up, first Philips
would start configuring / marking more parts as an LPC2104.
But if demand really takes off, they might spend $100000
(that sort of money) on a new mask set that only has enough
memory for the LPC2104 to get more chips per wafer.

It is possible that you could get an LPC2104 where the other
memory is merely turned off. But it might be turned off
because it doesn't work. And as soon as you start re-mapping
the memory away from what Philips' tests showed to be good,
all bets are off.

Going from Flash to ROM for the bootloader (without any
change in chip area) is probably only one mask change,
say $15000. The saving is that the bootloader does not have
to be programmed. But you still have to test the entire
memory.

My suspicion is based only on previous knowlege of the
semiconductor industry - I have no evidence for this
particular case. And the fact that Philips FLASH includes
error-correction cells does not make me think my suspicion
any less likely.

An interesting article on yeild and quality for
semiconductors was written by Bob Pease of National
Semiconductor and published in EDN in
http://www.elecdesign.com/Articles/ArticleID/6135/6135.html

Regards,
Danish
--- In lpc2000@yahoogroups.com, "jayasooriah" <jayasooriah@...> wrote:
>
> --- In lpc2000@yahoogroups.com, "unity0724" <unity0724@> wrote:
> >
> > Hello!!..  Bootloader...
> > Why not you do something more fantastic for group members here:
> > 
> > =>Something that able is to copy the bootloader from one chip 
> > to another.
> 
> You could (possibly) use it to upgrade LPC2104 to LPC2106 by simply
> copying the boot loader across.  Philips will not like this.
> 
> [Newer variants of LPC2104/5/6 are rom'ed, but the same applies to any
> other compatible variant that is not rom'ed.]