[En-Nut-Discussion] SAM9260-EK getting started

[Alain M.]

search for "ramfunc", I found it in sam7 code. It inicializes a prefix 
that sends a single function to ram. It can be further expanded to use 
both internal ram blocks.

Alain
PS: I send a message by mistake to the list, I was just checking info 
from some comments (it was in portuguese)

steve escreveu:
> Hi,
> 
>   Further to my problems getting the expected performance from the
>   9260 processor it seems the limiting factor is bus speed to the
>   external SDRAMs (notwithstanding the lack of clarity over whether
>   or not the caches are actually doing anything).  Given that the
>   max bus speed is 100MHz plus the necessary latencies in SDRAM
>   accesses this results in a best-case net performance NO BETTER
>   than a 48MHz ARM7!
> 
>   It would therefore seem that the only hope of achieving any
>   improvement on this would be if best use could be made of the
>   8Kbytes internal fast ram.  Does anyone know of any mechanism
>   to persuade the compiler/linker to place critical bits of code
>   / data and perhaps the stack in internal SRAM?
> 
>   Thanks a lot.
> 
> Cheers,
> Steve.
> 
> 
> At 14:01 13/07/2008, you wrote:
>> steve wrote:
>>>   If I program the webradio application into dataflash on my 9260-EK,
>>>   (along with the Atmel bootloader) then it works.  Programming directly
>>>   into SDRAM @ 0x20000000 it fails.  Clearly there's something in that
>>>   bootloader that makes all the difference, does this make any sense?
>> Indeed, there may be a missing initialization in the SAM-BA ROM or the
>> Webradio, which is provided by the boot loader. Unfortunately I haven't
>> had the time to test all this here. At least I do have the same board
>> revision 1.0.
>>
>>>   I now have another problem - my LJG JPEG decompression application
>>>   runs slightly _SLOWER_ on the 9260-EK (CPU clk 90.3MHz) than on my old
>>>   SAM7X-EK (CPU clock at 48MHz).  I moved to ARM9 specifically to get
>>>   more speed, does anyone have any idea why?
>> I had a discussion with Atmel about similar experiences with the MP3
>> fixed point software decoder used in the webradio. They later changed
>> the SDRAM initialization (SAM-BA script and bootloader) and performance
>> increased. It was still slower than expected, but significantly faster
>> than the SAM7X. In case you are using an old SAM-BA Tool or boot loader...
>>
>> Harald
>>
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