From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vladimir A. Gurevich <vag@paulidav.org>
Date: Sat, 18 Mar 2006 13:20:59 -0800
Subject: [U-Boot-Users] SPI EEPROM on MBX problem
In-Reply-To: <200603182135.45772.antonio.dibacco@aruba.it>
References: <200603182135.45772.antonio.dibacco@aruba.it>
Message-ID: <441C79BB.5050701@paulidav.org>
List-Id: <u-boot.lists.denx.de>
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To: u-boot@lists.denx.de

Hello Antonio,

Antonio Di Bacco wrote:

>I use the sspi command like this:
>
>sspi 0 8 05   (for Gurevitch patch)
> 05 is the code read a configuration register.
>
>Sometimes the EEPROM answer FF, some others 00 , it is completely randomic.
>  
>
The command you are using is not exactly correct. You specified only 8
bits to transfer and this is enough to only send the command (0x5). But
SPI master is also supposed to provide clock for the slave to answer.
So, use a different command:

    sspi 0 16 05

Then you'll see that the second byte of the response contains the corret
value.

Same applies when you decide to read your eeprom.

Happy hacking,
Vladimir