Hi,

I made some modifications to the BasicLCD example for AT91SAM9261-EK so that the code is copied from the dataflash to the external SDRAM and run from there. Only the init code loaded by the AT91SAM9261 boot program and the stack is at the internal RAM.

A test code that runs normally in 25 seconds when run in the internal memory takes about 100 seconds when run from the SDRAM. Is a performance hit of this magnitude something to be expected? Turning LCD controller DMA on and off has effect of about 10%. The following observation makes me think I'm missing something:

After loading the code into the dataflash, running the same test in the internal RAM (debugger shows the code really is running there) takes about 50 seconds. If I use SAM-BA to clear the dataflash, the same code again runs in 25 seconds.

Any ideas?

I am working on getting my code to run from SDRAM, but have not been successful. I would like to evaluate this slower performance that you are seeing. If you could give me some instructions to help me get some code running out of SDRAM, I will let you know what type of performance I see and if perhaps I can help to make it faster.

-Drew

Posting a basic project would help. Are you sure you are setting up the EBI speed properly? It should be under a 50% hit from the internal full speed SRAM to the 100MHz access SDRAM unless your code is also using the EBI as part of its functionality.

That being said - the whole cleared dataflash makes it faster is truly baffling.

I am working on getting my code to run from SDRAM, but have not been successful. Could you please guide me how to do that ??

even I am also working on some example project(led blink). give me the steps what are al thethings needs to modify.