Surviving 1 second without battery power

[peu]

Hi, Peu

NO, you did not understand ...

1) You enable BODEN, nothing else required ...

2) AT program start, you first read the BOR bit

3) If BOR Bit = 0 THEN (and only IF ) you increase the EEPROM content : That means power is back, and did not reach ZERO !!! ( no Pb to write , then ...)

4) If BOR Bit = 1 power has gone to ZERO ( and BOR bit has been reset ) ... just read the EEPROM content .

5) you SET BOR bit

6) you run your "lighting" program ...

Think simple !!!

Alain

I still have a doubt: when does the BOD bit goes from the initialization value ZERO (table 9-6) to ONE (No Brown-out Detect occurred) in a cold start scenario?

At cold start the circuit should read the stored eeprom value not write a new one