Atmel and dreams!

[Scott Chicoine]

There exists a basic ARM7 core.  The letters after "ARM7" refer to
additional core features.  "T" mean "thumb mode".  "M" means it includes an
efficient 32 x 32 -> 64 bit multiplier.  I'm less clear what the "D" and "I"
stand for, although I suspect the "D" means it supports
multiply-and-accumulate instructions.  Possibly "I" means "integer", i.e. no
floating-point support.

I've found that using the Thumb mode results in smaller overall code size,
but at the expense of speed.  You can switch in and out of Thumb mode within
a program.  Another set of tools I'm using from Green Hills Software
(http://www.ghs.com/products/arm_development.html) has a compiler that lets
you specify which functions are Thumb mode and which are straight 32-bit.

I've used Intel i960 (weird, complicated) and Hitachi SH, (obscure, hard to
find) and I've grown to like the ARM the best.  And, if you're one of those
sick puppies that likes to hand-optimize assembly, the ARM's instruction set
allows for some serious tweaking.

> -----Original Message-----
> From: Theo [mailto:t.hogers at home.nl]
> Sent: Monday, November 06, 2000 4:11 PM
> To: Scott Chicoine; patchell
> Cc: synth-diy at node12b53.a2000.nl
> Subject: Re: Atmel and dreams!
> 
> 
> Thanks Scott this is use full information.
> One question, is a ARM7TDMI core a ARM whit the extra THUMB 
> instructions?
> From what you're saying I understand it is.
> Those Atmel marketing goofs presented the Thumb thing as an Atmel
> development.
> 
> Regards, Theo
> 
> 
> ----- Original Message -----
> From: Scott Chicoine <ScottC at zeno.com>
> To: 'Theo' <t.hogers at home.nl>; patchell <patchell at silcom.com>
> Cc: <synth-diy at node12b53.a2000.nl>
> Sent: Monday, November 06, 2000 10:45 PM
> Subject: RE: Atmel and dreams!
> 
> 
> > (lurk_suspend)
> >
> > You don't really need an AT91 compiler, you just need an ARM7TDMI
> compiler.
> > The only thing unique about the AT91 is that Atmel 
> surrounded an ARM7TDMI
> > core with a bunch of their own peripherals.
> >
> > They're certainly not the only chip manufacturer to do this.  My
> particular
> > project uses the same CPU core in a different chip (see
> > http://www.netsilicon.com/products/embedded.asp).  The 
> development system
> > I'm using is Tornado/VxWorks from Wind River.  Yes, it's 
> out of reach of
> > hobbyists, but my point is that they use the GNU tools, 
> including a GCC
> port
> > for their compiler.  I'll bet somebody has posted a feely 
> available port
> of
> > the GNU tools for the ARM.
> >
> > I notice that Red Hat has an "embedded development kit" for 
> the ARM for a
> > reasonable fee (about $200?), which includes the GNU tools. 
>  It appears
> they
> > have, or are working on, an ARM version.  I suppose you 
> could get that
> > package and just use the tools, ignoring the Linux stuff.
> >
> > Lastly, how about ARM themselves?  They have a low-cost 
> evaluation board
> > available that comes a tool chain as well.
> >
> http://www.arm.com/sitearchitek/devtools.ns4/html/evaluator_7t
> ?OpenDocument
> > You might be able to use these tools on Atmel's board, too.
> >
> > (lurk_resume)
> >
> >
> > > -----Original Message-----
> > > From: Theo [mailto:t.hogers at home.nl]
> > > Sent: Sunday, November 05, 2000 11:30 PM
> > > To: patchell
> > > Cc: Bjorn Julin; synth-diy at node12b53.a2000.nl
> > > Subject: Re: Atmel and dreams!
> > >
> > >
> > >
> > > From: patchell <patchell at silcom.com>
> > > >
> > > > Theo wrote:
> > > >
> > > > > A budget (<$200) eval board for AT91  has been around
> > > since 2  years or
> > > so.
> > > > > However so far no budget programming language. :(
> > > > >
> > > >
> > > >     Nobody has ported the GNU compiler to the Arm?
> > > >
> > >
> > > Probably yes, but the AT91 are no standard ARMs.
> > > There has to be support for the additional THUMB 
> instruction set to be
> > > useful on the AT91 parts.
> > > Have to look into this some time.....
> > >
> > > Theo
> > >
> > > > >
> > > > > Hope this will change soon, ARM are way cool processors.
> > > > >
> > > > > Reg. Theo
> > > > >
> > > > > ----- Original Message -----
> > > > > From: Bjorn Julin <bnillson at hotmail.com>
> > > > > Cc: <synth-diy at node12b53.a2000.nl>
> > > > > Sent: Thursday, November 02, 2000 11:35 PM
> > > > > Subject: Atmel and dreams!
> > > > >
> > > > > > Hi!
> > > > > > Atmel is claiming this:
> > > > > >
> > > > > > Atmel's AT91 ARM Thumb microcontrollers provide
> > > > > > the 32-bit performance every 8-bit microcontroller
> > > > > > user is dreaming of while staying within his tight
> > > > > > system budget.
> > > > > >
> > > > > > Yes, i like to dream to, but about naked women!
> > > > > > Anyone seen any prices for the AT91??????
> > > > > >
> > > > > > BJ
> > > > > >
> > > > > >
> > > ______________________________________________________________
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> > > >
> > > > --
> > > >  -Jim
> > > > ------------------------------------------------
> > > > * Visit:http://www.silcom.com/~patchell/
> > > > *-----------------------------------------------
> > > > *If you didn't buy a home in Santa Barbara,
> > > > * You didn't pay enough!
> > > > ------------------------------------------------
> > > >
> > > >
> > >
>