[U-Boot-Users] Re : MV64460 Burst reads from BootCS

Jerry Van Baren gerald.vanbaren at smiths-aerospace.com
Mon Oct 2 14:14:09 CEST 2006


sebastien.douheret wrote:
> 	Hi,
> Marvell MV64460 only supports burst reads/writes on 32bits
> width peripherals ;-(
> I have the same issue with a Lauterbach probe. You must deny
> burst on BootCS if this peripheral is not 32bits width !
> This restriction also penalize boot process ! If your boot
> flash is 16 or 8 bits witdh, you can't directly execute
> instructions in flash. Because CPU like MPC74xx always load
> instructions with burst reads.
> 
> Regards.
> Sebastien.

I don't believe the above is strictly correct.  The 74xx does burst 
reads only if the cache is enabled for that memory area, so you should 
be able to execute out of flash but would be unable to enable caching on 
the boot memory area.  After all, I presume the board boots out of flash.

gvb




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