Review the SRM and the schematics.  The write protect for the on-board
EEPROM is a test point on the PCB.

On 5/26/2014 9:58 AM, Oscar Castiblanco wrote:
> How can I take the write protection off?, is it hardware or software this 
> protection?
> 
> On Tuesday, September 24, 2013 2:26:37 PM UTC+2, kiran gopalan wrote:
>>
>> Hi,
>>
>> I am trying to write to the main eeprom ( at i2c address 0x50) using the 
>> sysfs interface.
>>
>> I am able to read from this eeprom:
>>
>> =================
>> root@am335x-evm:/sys/bus/i2c/devices/1-0050# head -c 300  eeprom | hexdump 
>> -C
>> 00000000  aa 55 33 ee 41 33 33 35  42 4e 4c 54 30 41 35 41  
>> |.U3.A335BNLT0A5A|
>> 00000010  31 38 31 33 42 42 42 4b  32 30 35 39 ff ff ff ff  
>> |1813BBBK2059....|
>> 00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  
>> |................|
>> =================
>>
>> But I am unable to write anything to this:
>>
>> =================
>> root@am335x-evm:/sys/bus/i2c/devices/1-0050# echo "TEST" > eeprom 
>> root@am335x-evm:/sys/bus/i2c/devices/1-0050# head -c 300  eeprom | hexdump 
>> -C
>> 00000000  aa 55 33 ee 41 33 33 35  42 4e 4c 54 30 41 35 41  
>> |.U3.A335BNLT0A5A|
>> 00000010  31 38 31 33 42 42 42 4b  32 30 35 39 ff ff ff ff  
>> |1813BBBK2059....|
>> 00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  
>> |................|
>> *
>> 00000120
>> root@am335x-evm:/sys/bus/i2c/devices/1-0050# 
>> =================
>>
>>  I am not seeing any error messages in dmesg.
>>
>> AFAIK this EEPROM is write enabled and I am not required to do any extra 
>> configuration.
>>
>> Can anyone help me to make this work?
>>
>>
>> Kiran 
>>
>>
>>
>>
> 


-- 
Charles Steinkuehler
[email protected]

-- 
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