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Flash on EVMDM642

Started by kalai vani June 27, 2006
Hi,
I am using EVMDM642 board in Flash boot mode. I have a few doubts regarding bootloading using Flash.
The bootloader stub (1 KB) is copied from Flash base address 0x90000000 to the RAM address 0x0000. The bootloader stub then configures the EMIF and then copies all sections from Flash to ROM on bootup.

1) How is the EMIF configured to copy the first 1KB of bootloader stub from Flash base to 0x0000?
2) Is there any default settings for the EMIF registers on RESET which it uses to copy the bootloader stub from the Flash?
3) In the EVMDM642 board, the Flash chip used is Am29LV033C. In case a different Flash chip is used, would the default EMIF settings change due to different timings for the new Flash?
4) If the default settings would change, how to set the EMIF registers to have another default value on RESET?

Thanks in advance,
Kalaivani.S
hi,

1)and 2): EMIF is used as it is. ie: with register
settings at reset.
3)and 4):as far as i understand, the reset settings
are maximum values. So ideally,there should not be any
problem even if you use a different memory chip which
falls within the allowable range.

regards,
Dileepan.
--- kalai vani wrote:

> Hi,
> I am using EVMDM642 board in Flash boot mode. I
> have a few doubts regarding bootloading using Flash.
>
> The bootloader stub (1 KB) is copied from Flash
> base address 0x90000000 to the RAM address 0x0000.
> The bootloader stub then configures the EMIF and
> then copies all sections from Flash to ROM on
> bootup.
>
> 1) How is the EMIF configured to copy the first 1KB
> of bootloader stub from Flash base to 0x0000?
> 2) Is there any default settings for the EMIF
> registers on RESET which it uses to copy the
> bootloader stub from the Flash?
> 3) In the EVMDM642 board, the Flash chip used is
> Am29LV033C. In case a different Flash chip is used,
> would the default EMIF settings change due to
> different timings for the new Flash?
> 4) If the default settings would change, how to set
> the EMIF registers to have another default value on
> RESET?
>
> Thanks in advance,
> Kalaivani.S
>
>
>
__________________________________________________
Hi,
According to my understanding:
1,2) The first 1K part is automatically copy by the
on-chip bootloader from flash to ram (see
spra999.pdf). But after this when the control comes to
your application, either you jump to _c_int00 point of
your application or write 2nd level bootloader for
some other initialization.
3) If you are using some other flash and timings are
different then you have to change the EMIF register
settings too.
4) Change the EMIF register settings........see any
reference code for this.

Bye.

> > Hi,
> > I am using EVMDM642 board in Flash boot mode.
> I
> > have a few doubts regarding bootloading using
> Flash.
> >
> > The bootloader stub (1 KB) is copied from Flash
> > base address 0x90000000 to the RAM address 0x0000.
> > The bootloader stub then configures the EMIF and
> > then copies all sections from Flash to ROM on
> > bootup.
> >
> > 1) How is the EMIF configured to copy the first
> 1KB
> > of bootloader stub from Flash base to 0x0000?
> > 2) Is there any default settings for the EMIF
> > registers on RESET which it uses to copy the
> > bootloader stub from the Flash?
> > 3) In the EVMDM642 board, the Flash chip used is
> > Am29LV033C. In case a different Flash chip is
> used,
> > would the default EMIF settings change due to
> > different timings for the new Flash?
> > 4) If the default settings would change, how to
> set
> > the EMIF registers to have another default value
> on
> > RESET?
> >
> > Thanks in advance,
> > Kalaivani.S
> >
> >
> >
> >
> >
> __________________________________________________
>
>
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