Lpc2000

--- In lpc2000@yahoogroups.com, Robert Adsett <subscriptions@...> > 
I don't care about virtualization or compressing the heap but making 
sure 
> only certain processes can write to specific address ranges, now 
that I'd 
> like to see.  I just haven't seen an implementation on a 
microcontroller yet.
> 
> Robert
> 

If you're looking for an ARM9 or similar with MMU try the Cirrus 
Logic EP9302 - see http://tinyurl.com/8v9ar or one of the Intel 
Xscale parts - see http://tinyurl.com/psbfv

Of course, it's debatable wither these are microcontrollers or not, 
but both have CPU, MMU, (some) memory and a peripheral set on-board.

I agree that the primary use of MMU is to support protected mode 
operating systems: I can't see how it would really help with 
compressing heaps etc. Although protected mode operating systems 
used to be associated with "big systems", there's no doubt there's a 
big move to them for embedded systems. Costs are falling, Linux is 
available, demand for smarter and more general purpose systems 
increasing etc.

Right now you can go from a $1 Cortex processor to a $10 ARM9/MMU 
micro with a lot of blurring in between in terms of CPU performance, 
on-board memory size and mix, MMU support, peripheral mix, pin-count 
etc. In other words, there's plenty of choice out there, and more 
every day. 

Due to the range of parts, cost and track record I'd expect Philips 
to continue to do well at the low end with the LPC2000. No doubt 
they're hoping to do as well at the higher end with the LPC3000 
series, but I'd say it's still pretty open as to who will be the 
winner in that space. Just an opinion, of course....

Brendan