Beaglebone Black RTC issue

user4142249

Prodigy 90 points

Hardware Rev:beaglebone black RevC

linux platform: SDK6.0

System time add 131073s to the current time(RTC) sometime; checked the hardware, the osc gnd both to GND.

Then, which cause this issue? Is there happen this issue?

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Do you see the same issue with newer SDK versions?

0 user4142249 over 9 years ago in reply to Biser Gatchev-XID

Prodigy 90 points

Dear Biser，

We have use SDK6.0 long timer and test in the long term. We will have to retest while use newer version SDK. We want to resolve this fault in sdk6.0, if you have any suggestion, please tell me, thank you very much for your kindly help.

BRS

0 user4142249 over 9 years ago in reply to Biser Gatchev-XID

Prodigy 90 points

Dear Biser,
while you have any idea about this issue please let me know, I will try, thanks
BRS

0 Biser Gatchev-XID over 9 years ago in reply to user4142249

TI__Guru**** 393215 points

Is this a real BBB board or a custom board?

0 user4142249 over 9 years ago in reply to Biser Gatchev-XID

Prodigy 90 points

real BBB board;

BRS

0 Biser Gatchev-XID over 9 years ago in reply to user4142249

TI__Guru**** 393215 points

Are you using RTC in RTC-Only mode? If so, you are forced to use the 32.768 kHz crystal clock source from OSC1. If you only use RTC when the processor is powered, RTC can be clocked from an internal 32.768 KHz clock source that is divided down from one of the DPLLs. This would be the preferred option in this use case since this clock source is less susceptible to noise.

If you need to use OSC1 to support RTC-Only mode, it is important to understand if noise is coupling into the crystal circuit. Connecting the crystal circuit grounds per our latest recommendation increases noise immunity, but this does not guarantee the crystal circuit is 100% immune to noise. You may want to temporarily remove the crystal components and dead-bug a 1.8 volt LVCMOS clock source on the board to see it eliminates the issue. This will confirm if noise coupling into OSC1 is causing this issue.

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Beaglebone Black RTC issue