data retained when eeprom cleared

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REPROGRAMMING AVR YOU LOOSE ALSO THE DATA IN EEPROM.IF I COPY THEESE DATA IN RAM BEFORE PROGRAMMING, AND ASSUMING NO POWER OFF WILL DATA BE INCORRUPTED
WHEN PROGRAMMING END? THERE COULD BE SOME UNKNOWN FACTOR THAT DESTROYS MY
DATA? I DON'T HOPE SO. HAVE YOU ANY SUGGESTION ?I

charlie

If at first you don't suceed...
hook up the logic analyzer.

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Hello Charlie,

The EEPROM shouldn't be automatically erased when you program your Flash (program) memory. Could it be you're using the AVR ISP software and the "Autoprogram" button? This button could be configured to erase your EEPROM. Please check "Program->Auto-Program Options..." if you're using this software.

If I haven't answered your question, please specify.

Morten, Atmel FAE

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Ooops! My bad... :)

Please see Jacob's answer instead, in the thread above this one.

Morten

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PROBABLY MY QUESTION WAS NOT SO CLEAR. I'LL TRY TO EXPLAIN BETTER MY PROBLEM.
I HAVE A SYSTEM THAT COMUNICATES WITH MANY AVR8 RISK(8515).THEY ARE CONNECTED IN PARALLEL THROUGH MOSI-MISO AND SCLK.WHEN I PROGRAM, I SEND THE SAME SOFTWARE TO ALL THE RISKS SO THEY SHARE THE SAME PROGRAM BUT HAVE DIFFERENT DATA CONTENT IN EEPROM.YOU KNOW THAT EEPROM IS ERASED WHEN YOU PROGRAM THE FLASH, SO I TRYED TO SAVE,BEFORE PROGRAMMING, THESE EEPROM DATA INTO RAM.AFTER THE PROGRAMMING PHASE A COPY RAM DATA BACK TO EEPROM. THIS IDEA SEEMS OK BUT FOR SOME REASON DOESN'T WORK(I'M NOT SO SURE).MY QUESTION IS:THERE MAY BE SOME REASON THAT DESTROYS MY DATA IN RAM WHEN I SEND A NEW PROGRAM IN AVRS?
THANKS FOR A PROMPT REPLY.

charlie

If at first you don't suceed...
hook up the logic analyzer.

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Hi Charlie,

The SRAM should not be changed by the programming of the FLASH, but some compilers link a initialisation of SRAM into your program. The initialisation code is run first when code the part starts. Could this be the problem? (Did you read my posting in the thread above this thread?). Still, if you power down the part after the programming of it - the contents of the SRAM is most likely lost.

Since you believe you experience that the SRAM is changed, please describe the procedure that you are following - then we might be able to locate the problem. How are the lines connected, what programming tools are you using, how do you read out/verify the contents extracted from the EEPROM. Please provide most possible info.....

Jacob L. Lassen
Field Applications Engineer,
AVR products, Atmel

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I DON'T USE ANY AVAILABLE SOFWARE FOR PROGRAMMING; I USE ANOTHER MICROPROCESSOR THAT SENDS THE RIGHT PROTOCOL WRITTEN I ASSEMBLER.
THE ONLY THING I MAKE IS TO SEND THE COMMANDS FOR SERIAL PROGRAMMING.
I'M SURE THAT THE RISKS ITSELF DON'T WRITE ANY DATA IN THE SRAM EXEPT THE DATA FROM EEPROM.BYE CHARLIE

charlie

If at first you don't suceed...
hook up the logic analyzer.