hi sir, i am new to this rtc ds1307 and want to know dat according to its datasheet it is battery backed....does that mean that you need not initialize it when you use it for the first time?????
and if i want to simulate it on proteus software it shows correct date and time automatically without writing it for the first time.....
i m unable to understand all this plzzz help me out....and i m sorry if i irritated you...
Doesn't matter if a RTC have battery or not. Your code must still make a decision if you believe it has a valid time or not, when your device boots.
Next thing is that if you did read the datasheet, you would know that the DS1307 do not have any internal battery. It just supports a battery. Didn't you look at the "Typical operating circuit" picture in the datasheet.
Third thing is that even if a RTC "has time", it will slowly drift. So you need to give the user a way to correct the time.
Fourth is that even when the time is perfect, you will either have to replace a battery or (if using a supercap) suffer the results of the battery running dry. So it doesn't matter if the RTC at some point have had a valid time.
By the way - why ????? or large numbers of .....?