Lpc2000

Hi Brian...

>> [Bill Wiese wrote:]
>> While code protection is "nice", you shouldn't count 
>> on it 100% and bet your future on it. Licensing 
>> contracts,  patents, etc. also have their roles.

> [Brian Lane wrote:]
> That is true, but doesn't help you at all when some anonymous 
> chinese company clones your new widget. It also doesn't help 
> much if you don't have 100k budgeted for lawyers to enforce 
> your patents.
> I have no faith in protection offered by patents or contracts. 
> I need to keep my code as secure as possible, given the 
> application and distribution of the device.

Yeah, I know. A patent is really just the "right to sue". And if you
let something slide by not defending it (because of time or financial
constraints) that can work against your patent because you "allowed" it
to happen.

>>[Bill Wiese wrote:]
>> A few years ago, in a past life doing reverse engineering, 
>> I managed to dump data from variety of 'secure' CPU ROMs, 
>> including oddball Japanese parts....

>[Brian Lane wrote:]
> I've never done any of that, but it sure sounds like an 
> interesting challenge. I have been surprised at the abuse 
> I can sometimes expose a chip to and have it survive :)

It was a LOT of fun. (Mostly for tweaking engine control firmware.)

In lotsa chip co's you'll see decapped ICs hanging around an engineer's
desk - on a working prototyping PCB. Say the chip has a bad subsystem
(i.e., jams the bus or gets really happy issuing interrupts).  Rather
than take time to re-spin new silicon, a small batch of chips will get
the troublesome subsystems deactivated via FIB work (Focused Ion Beam
?) and maybe even a couple of metal patches and the rest of the chip
can be tested/exercised. With passivation layer removed oxidiation can
take place but at least you have a chip that can be exercised for a
bit..

>>[Bill Wiese wrote:]
>>And the attacker has to figure out the same thing in 
>>reverse: how much effort is this task worth?
 
>[Brian Lane wrote:]
> That's the bottom line. And the LPC doesn't provide anything 
> that would prevent someone from cloning the chip using the 
> JTAG interface. You can cut the pins, but that introduces 
> extra assembly cost, and how hard is it to scrape off some 
> of the chip's plastic and re-attach to them?
> 
> Plans for future code protection in the LPC don't help us now. 
> And they are likely to be an after-thought when it ought to 
> have been included from the start.

You do have to know that the LPC21xx parts are intended as low-cost
microcontrollers - that is, 32-bit successors to 8051-like devices.
They're not positioned as ARM "system chips" like other ARM devices.
In the grand scheme of things the ARM CPU core itself prob doesn't take
much more die space than an 8051 core. The flash (charge pumps) and RAM
will take more area, so the ARM core is a cheap way of selling more
silicon ;)

The co's Philips is catering to are usu bulk buyers/bigger co's, so
little guys' complaints are prob not on the radar screen. Big guys can
use their legal prowess to avoid your issues....

Bill Wiese
San Jose CA






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Hi Bill (Wiese),

> You do have to know that the LPC21xx parts are intended as low-cost
> microcontrollers - that is, 32-bit successors to 8051-like devices.
> They're not positioned as ARM "system chips" like other ARM devices.
> In the grand scheme of things the ARM CPU core itself prob doesn't take
> much more die space than an 8051 core. The flash (charge pumps) and RAM
> will take more area, so the ARM core is a cheap way of selling more
> silicon ;)

I read your post with great interest, and as you can tell I'm quite new to
ARM.
It seems sign of the times is that we can expect single chip RF ICs with MCU
on-board to run ARM rather than the 8051 sooner than later, so I really need
to get in on the game :-)

I found thsi interesting article here :
http://www.heyrick.co.uk/assembler/history.html

I had no idea ARM came from Acorn ?
I really liked this bit (excerpt) :
"So when, in the early '90s, Apple announced the world's first RISC desktop
machine, we laughed.
And Acorn ran a good-humoured advert in the Times welcoming Apple to RISC."

Rather intrueguing.

-- Kris

On Mon, Feb 23, 2004 at 05:36:39AM +1100, microbit wrote:
> Hi Bill (Wiese),
> 
> > You do have to know that the LPC21xx parts are intended as low-cost
> > microcontrollers - that is, 32-bit successors to 8051-like devices.
> > They're not positioned as ARM "system chips" like other ARM devices.
> > In the grand scheme of things the ARM CPU core itself prob doesn't take
> > much more die space than an 8051 core. The flash (charge pumps) and RAM
> > will take more area, so the ARM core is a cheap way of selling more
> > silicon ;)
> 
> I read your post with great interest, and as you can tell I'm quite new to
> ARM.
> It seems sign of the times is that we can expect single chip RF ICs with MCU
> on-board to run ARM rather than the 8051 sooner than later, so I really need
> to get in on the game :-)
> 
> I found thsi interesting article here :
> http://www.heyrick.co.uk/assembler/history.html
> 
> I had no idea ARM came from Acorn ?

<nostalgia>
I remember when I was lucky to have an ARM2 in my Acorn A3000!
(those where the days, a man, his machine, and only a copy of BBC
BASIC Assemler for company)
</nostalgia>

I'm sure there must be others on here who've been working with ARM at least
as long?

-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.

> <nostalgia>
> I remember when I was lucky to have an ARM2 in my Acorn A3000!
> (those where the days, a man, his machine, and only a copy of BBC
> BASIC Assemler for company)
> </nostalgia>
> 
> I'm sure there must be others on here who've been working with ARM at least
> as long?

*sniffle*  Not me.  I'm an American living in the states and I've only been
able to worship them from afar.  I bought my first ARM a few years ago in
the form of a Webpal.  A little 40MHz 7500FE core set top box.  One of the
few ARM with a real FPU. Too bad nothing supports it. :(  It's now got a
small hard drive, 32 meg of memory, and runs Debian Linux in my closet.

*warning*

So, I guess you could say, I'm a closet ARM fan.

*ducks*

Cheers,
David

microbit wrote:

> I found thsi interesting article here :
> http://www.heyrick.co.uk/assembler/history.html
> 
> I had no idea ARM came from Acorn ?

Oh, yes. And it was designed by just one man and one woman, although the 
woman was sort of trapped in a man's body at the time, if I recall 
correctly, although mention of Sophie having been called Roger at the 
time is now rather scant - I gather she prefers not to be reminded.

http://en.wikipedia.org/wiki/Acorn_RISC_Machine
http://www.sophie.org.uk/
http://www.cs.man.ac.uk/apt/new/people/sfurber/

ABS

Ben Dooks wrote:

> <nostalgia>
> I remember when I was lucky to have an ARM2 in my Acorn A3000!
> (those where the days, a man, his machine, and only a copy of BBC
> BASIC Assemler for company)
> </nostalgia>
> 
> I'm sure there must be others on here who've been working with ARM at least
> as long?

My first contact with them was on Acorns. Ah, Econet! *FX! My current 
ARM instruction set reference, in fact, is the Dabhand Guide, which 
assumes I'm using the BASIC assembler...

ABS