5.3.5 Preventing EEPROM CorruptionDuring periods of low VCC, the EEPROM data can be corrupted because the supply voltage istoo low for the CPU and the EEPROM to operate properly. These issues are the same as forboard level systems using EEPROM, and the same design solutions should be applied.An EEPROM data corruption can be caused by two situations when the voltage is too low. First,a regular write sequence to the EEPROM requires a minimum voltage to operate correctly. Secondly,the CPU itself can execute instructions incorrectly, if the supply voltage is too low.EEPROM data corruption can easily be avoided by following this design recommendation:Keep the AVR RESET active (low) during periods of insufficient power supply voltage. This canbe done by enabling the internal Brown-out Detector (BOD). If the detection level of the internalBOD does not match the needed detection level, an external low VCC reset Protection circuit canbe used. If a reset occurs while a write operation is in progress, the write operation will be completedprovided that the power supply voltage is sufficient.
Why do you think it's disabled, have you read the fuses out?
Thanks Jack,So that quote, sounds like a brownout problem if trying to write to EEPROM.
Secondly, the CPU itself can execute instructions incorrectly, if the supply voltage is too low.
I have read on the internet, that "by default, the boards have the brownout disabled".
If you are not logging data into the EEPROM, does that mean brownout is not a problem?
No, for the reason stated above. I probably worry about these things more than other folks.
You mean you worry about the program not running correctly?
You think it will send signals to devices that will cause them to burn up? Please elaborate.
Embedded designers can't afford "the blue screen of death." Desktop operating systems can get rebooted every so often, but embedded systems--good ones, at least--often have to run for years without a single reboot or power cycle. Medical devices are one obvious example in which reliability is absolutely paramount. But industrial-automation systems, security systems, motion controllers, automotive systems, and most other embedded devices have to be just as reliable. And that means building on a reliable foundation.
why do we not have more people on this thread. If you play poker, (Jacks or better), we just barely make it here. LOL
Well, I don't let this out often, so keep it under your hat. My parents named me Jackie. Don't you ever call me that tho. LOL
For what it's worth, that point is somewhere below 1.6V for the ATtiny85V I tested.
What speed were you using?
(Or were you testing SRAM data retention?)