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ADM1069 EEPROM default value


I would like to ask what is the default value of ADM1069 EEPROM after manufacturing??

The value in EEPROM after it is erased is 0xFF in each register. 

I have following issue. I am developing an Extension module. There is and I2C interface to this module from

main board. The idea I am using is that after system is powered on for the first time with new module, the

SW of main system detects that there is no data in EEPROM of ADM1069. I am using few bytes from scratchpad

area to achieve this. If certain bit is in 0x1 I consider it as empty. Next, the SW will erase the EEPROM and

write new configuration (In,Out, Sequencing engine, ADC etc...) to EEPROM. At the end I mark this bit to

0x0, which gives SW information that ADM1069 now has configuration (during next startup) and does not

need to erase and program EEPROM again!

But what is the value of the output pins after first startup, if the EEPROM is not programmed before?? If the value

in whole EEPROM is 0xFF, then it is automatically downloaded at first start-up. Thus each output register PDOxCFG

is programmed to 0xFF. That means that according to CFG6...CFG4 bits each pin has 100 Khz clock on output!

I can observe this behaviour when I erase the EEPROM and then restart the circuit. After download from EEPROM

to RAM outputs are driven with 100 Khz clock. This is not really acceptable since outputs are connected to enable

pins of power supplies...  I dont really want the switching controllers go trough this kind of shock after first power up...

Could someone please explain me where do I have a mistake in my thinking?? Or is there 0x00 the default value

in the EEPROM after manufacutere and I am responsible for first erasing, then writing configuration without

re-powering, if I want to avoid having clock on outputs? Or is it intended behaviour to have clocks on outputs

at first power up???

Ondrej Ille

  • Hi Ondrej,

    The default values in the EEPROM of a new part is 0x00, which means the PDO will be disabled with weak pull down.

    So if you're writing your configuration with your own program you need to erase the EEPROM first and then write configuration data before you power cycle. When you power cycle after you write your configuration data to EEPROM it will redownload that data at power up. 



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