MSP430F5338: Quickest way to enable RTC after Reboot

John Fedak

Expert 6715 points

Part Number: MSP430F5338

Hi MSP430 Team,

Good afternoon, my customer is interested in the quickest way to enable RTC after reboot:

It seems the RTC is placed in HOLD automatically upon re-boot and then needs to be enable and re-configured… we are trying to determine the most efficient way to do this and have the least “loss of time”. (When the RTC is on HOLD, we are essentially losing time which impacts our overall accuracy).

Please let me know if there are any questions.

Regards,

~John

over 5 years ago

0 James Evans over 5 years ago

TI__Mastermind 49692 points

Hello John,

Please take a look at the following related thread and app note. These should help answer your questions.

MSP430F5335 RTC Stops running

Using the MSP430™ RTC_B Module With Battery Backup Supply

Regards,

James

0 John Fedak over 5 years ago in reply to James Evans

TI__Expert 6715 points

Hi James,

Thank you for the link to the other thread - there is a follow-up question:

Is there any expected amount of RTC time loss during a power transitions, such as, as long as the reset line is held, the RTC will not increment. Or any other equivalent specifications. Or is the design setup in such a way that as long as there is a battery backup and SW does the transition correctly, not a single clock edge should be missed.

Regards,

~John

0 James Evans over 5 years ago in reply to John Fedak

TI__Mastermind 49692 points

Hello John,

Have you had a chance to read through the app note that I linked above, Using the MSP430™ RTC_B Module With Battery Backup Supply? These details are discussed in great detail there, specifically main power supply transitions. If there is a power failure on the Battery Backup System, then the RTC won't continue to count. Obviously, the time loss will be equal to how long that power failure lasts.

Regards,

James

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MSP430F5338: Quickest way to enable RTC after Reboot