[U-Boot-Users] Configure the wait states

Ulf Samuelsson ulf at atmel.com
Fri Mar 2 09:01:30 CET 2007

----- Original Message ----- 
From: "JOAKIM NORDELL" <TDE02003 at stud.mah.se>
To: <u-boot-users at lists.sourceforge.net>
Sent: Friday, March 02, 2007 7:57 AM
Subject: [U-Boot-Users] Configure the wait states

> Hello.
> I'm working with a Atmel AT91RM9200 board and I would like to set the memory timing. I think that the board can be faster, the read from and write to memory can be done faster than now. So, I would like to laborate with the wait state register. Is that possible to do inside of u-boot or within the source code?
> Greetings
> ---
> Joakim Nordell

It is possible to change anything in U-Boot source, but
I am not sure U-boot supports writing to the EBI while you are executing
from SDRAM

The bus will run the internal/external bus at a fraction of the CPU speed.
I believe you should be able to run the bus at 80 Mhz or so, but
that means that you have to reduce the CPU speed to 160 MHz
from 180 MHz, and I am not sure you gain anything in the process.
The AT91SAM9260 has about the same functionality but can
run the bus at 100 MHz.

Best Regards
Ulf Samuelsson

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