Thanks for your advice !
--- In Curtis Monroe <> wrote:
>
> On January 17, 2007 08:55 am, Christopher Friedt wrote:
> > Hi James,
> >
> > Neither of these boards will execute any code from flash as
opposed to
> > ram, that would hinder the processor drastically. I don't even
think the
> > processor supports program addressing in flash-based devices.
>
> Technically NOR flash can execute code in-place (XIP). See article:
> http://www.edn.com/article-partner/CA6257144.html
>
> Nand Flash cannot XIP. It works more like a hard drive loading and
storing
> sectors. Nand also need to correct errors that occur in each pages
(ECC), NOR
> doesn't.
>
> I'm not sure if the TS-7200 with NOR flash uses XIP. But that
should not
> really matter. The EP9302 (or EP9301 on earlier TS-7200 boards)
has enough
> cache to store most of your critical code. Its the speed of the
cache that
> will be the biggest factor.
>
> So Nor and Nand will only make a difference in the speed of
loading code to
> your cache. Once the code is in the cache it will go at top speed!
>
>
> >
> > You're looking at nearly the exact same execution time. There
would only
> > be a very slight difference if one board had 32 MB sdram and one
had 64
> > MB sdram, since a board w/ 64 MB sdram has a dis-contiguous ram
layout
> > and thus would require a very very slight overhead in page table
> > translation from virtual addressing -> physical addressing.
>
> The 32MB sdram is discontinuous too. The EP9302 stores data and
code in the
> cache indexed by its virtual address, not its physical addresses.
So once the
> code is in the cache it does not need address translation to get
fetched
> again. So address translation will not slow it down.
>
>
> >
> > ~/Chris
> >
> > twhk2007 wrote:
> > > Hello all !
> > >
> > > TS-7200 uses NOR flash while TS-7260 uses NAND flash. I know
that the
> > > read time for NOR flash is faster than that of NAND flash. I
will use
> > > the board to do a lot of floating point calculations. Could
you anyone
>
> You may look into downloading the Cirrus Logic GCC compiler with
Maverick
> Crunch enabled. This could double the speed of your code. The only
problem is
> the TS Linux kernel does not support Maverick Crunch. So it isn't
initialized
> and you can't have more than one task using it, as the Crunch
registers are
> not preserved between tasks. You will also have trouble linking to
libraries
> that were not compiled with it.
>
> Some people have ported Linux 2.6 kernels that should support
Crunch.
>
> -Curtis.
>
>
> > > on the execution speed for these two boards ? Some people
mention that
> > > the code in NAND flash will be transfered to SDRAM during
excution, so
> > > the excution speed of a NAND flash-based board can be faster
than NOR
> > > flash-based board. Is this true for TS-7260 ?
> > >
> > > Best regards,
> > > James
> > >
> > >
> >
>
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