Re: Do you see any future to the 8-bit MCU's?



On Fri, 22 Jul 2011 06:46:58 -0700, linnix wrote:

On Jul 21, 2:24 pm, Tim Wescott <t...@xxxxxxxxxxxxxxxx> wrote:
On Thu, 21 Jul 2011 12:15:19 -0700, linnix wrote:
On Jul 21, 11:14 am, Tim Wescott <t...@xxxxxxxxxxxxxxxx> wrote:
On Thu, 21 Jul 2011 11:06:23 -0700, linnix wrote:
On Jul 21, 9:46 am, Tauno Voipio <tauno.voi...@xxxxxxxxxxxxxxxxxx>
wrote:
On 21.7.11 6:30 , Antoni Lacasta i Sullà wrote:

Hi,

During the latest months I have been receiving offers for
32-bit MCU's, mostly based on ARM-Cortex CPU's, at prices I'm
currently paying for 8-bit devices, or even cheaper! This has
brought me to benchmark them with the MCU independent part of
my C++ code and surprisingly the results are quite similar.

Same price, same flash consumption ... what do yo think? Is
this the end of the 8-bit's? I guess it is.

Regards,
Toni.

I just redesigned an old card using a 8051, an A/D converter, a
static RAM (2 kilobytes) and some glue logic. The new card was
done with a Stellaris Cortex, LM3S818. All the IC:s on the new
card costed together less than the A/D converter chip on the old
design.

When our current AVR -based designs need to be replaced, the
Stellaris chips are the potential replacements.

The Stellaris chips run fast with minimal electricity, but there
is the price of a quite complicated set-up of the master and
peripheral clocks and port pins.

Except for the price of the tools.  AVR and PIC tools are still
much cheaper.  We expect to spend around $1k for the new tools;
unfortunately, the cheap/low cost version won't cut it.

I'm using the gnu-arm tool chain, built from source*.  It works
fine.

Does it work for Freescale's Cortex M4 w/ DSP?

I don't know -- but it took to the Cortex M3 like wildfire.  I suspect
that the best you could hope for would be that the 'ordinary' C and C++
stuff would compile just fine, but anything DSP would have to be done
in assembly, by hand.

But then, that's the best I've ever gotten out of a 'paid for' tool
chain.

How much does CodeSourcery want for the 'real' tools?

Around 1K for most of them.

Then unless you're facing a period of forced unemployment, just plain
want to learn how to build the tools, or head up a big group and can
set one person to being "the tools guy" it's probably worth it to buy,
or to try out their free tool chain.


Yes, we are going to need DSP. I have fixed gcc and gas before. I can
probably hack in the necessary DSP instructions. I still need some kind
of JTAG/SWD programmer. Do TI/LMI and NXP programmers work on other
chips? If not, i will get the Freescale one.

I am still waiting for the customer decision for this. If we buy, we
would need at least two licenses. If we build on a virtual server,
there is no limit.

I don't know about specific company's programmers -- so far I've only
used TI's. But I do know that the ARM JTAG programming interface is
pretty generic. Your best bet for a programmer may be to get a 3rd-party
one that's optimized for speed, or just get one of the cheapie Olimex
ones that's optimized for price.

--
www.wescottdesign.com
.