MSP430 RTC_C

The MSP430F6736 has an auxiliary supply system (AUX), not the battery backup module (BAK). There are other differences between RTC_B and RTC_C. So I doubt the code will work for you.
Note that AUXVCC3 powers the RTC and the crystal. If it isn’t powered, both won’t operate.

And please don't ask the same question in multiple threads. It won't increase teh chance for an answer - it will only split the answers between multiple locations, making the forum less effective.

Sorry Jens,

The other thread seems to be created in 2011-12 and it does not have the complete answer, so i did created this new thread ..

I am using MSP430F6736 device where my 3v battery for RTC is connected to AUXVCC3 .. What i am observing is in power off condition, the RTC is holding the old value and it is not running.. The MSP430 user guide does not talk much about using the AUXVCC3 for the battery back system ... Please clarify.

I have the following observations today.

1.SVSHE and SVMHE bits are enabled by default on reset . When i disable the the supervising and monitoring for the High side, the RTC stops working even during the power on condition . WHY ??? .The values hours,mins,secs,day...all are read as zero.How does turning off SVSH affects RTC operation ?

2.If SVSH is enabled , whenever i turn off the DVCC power, does it not cause a Device RESET ? If it does , it is going to set the RTCHOLD bit as 1, which will eventually stops the RTC .

Any comments / suggestions will be greatly appreciated.

Thanks.

Sheik M said:

2.If SVSH is enabled , whenever i turn off the DVCC power, does it not cause a Device RESET ?

That’s what I guessed in the other thread.
And the calendar registers keep the old time because they are not initialized by a reset, and they didn’t lose power, so they are unaffected.

I haven't used the aux system myself, so I don't know all the reations between SVS and AUX. I'm sure the explanation is somewhere in the users guide.
The problem with the guide is, that you can't just look-up the informaiton you need. You need to read the whole chapter and then when you read this here, you'll have to rememebr that you also read that there and the two fit.
But that's a general problem. if all cross-dependencies were listed, the users guide would be ten times as big.

It might be that clearing the high-side monitoring the wrong way might set a lock on the registers (like in LPM3.5) and your RTC configuration doesn't take effect unless you clear LOCKLPM5. Yes, all those any features are making certain tasks quite complex. But everyhting that makes one application easier, makes a different one impossible.

It also bother me a lot .is it already applied ?

by th way, I use MSP430F6734