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Posts: 7
Registered: ‎06-15-2017
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EFM8SB1 RTC output

According to the reference manual, on the RTC I can assign a "Buffered clock output available for other system devices even in the lowest power mode." 

 

I take it that this is RTCOUT marked on the pin assignments for Port 0.2 and is the RTC clock signal i.e. a 16KHz waveform if using the Lowest frequency internal oscillator or am I mistaken in my interpretation?

 

Obviously I need to set P0MDIN, P0MDOUT, P0SKIP so that it is an output and included in XBAR enable but once this is done can anyone tell me how I actually assign the RTC output to the pin?

 

Posts: 2,112
Registered: ‎10-14-2014

Re: EFM8SB1 RTC output

@ChrisBD

It looks this part of document is not clear enough. I don't see the RTCOUT was controlled by crossbar in the section 12 of the reference manual. I suggest you filed a ticket http://www.silabs.com/support/Pages/default.aspx

and let Silabs to confirm if this a document mistake and really RTCOUT could routed to a GPIO.

 

My views are my own and do not necessarily represent the views of Silicon Labs

WeiguoLu
Posts: 7
Registered: ‎06-15-2017

Re: EFM8SB1 RTC output

Thank you.

As per your suggestion I've raised a support ticket.

Posts: 2,112
Registered: ‎10-14-2014

Re: EFM8SB1 RTC output

Thanks a lot, I saw it. Let wait for the answer from our AE support team.

 

WeiguoLu
Posts: 454
Registered: ‎02-21-2014

Re: EFM8SB1 RTC output

It's actually in the PMU0MD register, bit 7. This is in an awkward place, and difficult to find. We'll update the reference manual to make this easier to find in the future.

 

MCUAPPS-8705

Posts: 7
Registered: ‎06-15-2017

Re: EFM8SB1 RTC output

Found it.

Thank you.

I'd have found it if they had both been given the same name e.g. RTCOUT or RTCOE, so a change to make it easier to find would be great.

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Posts: 454
Registered: ‎02-21-2014

Re: EFM8SB1 RTC output

Yep. The plan is, at the very least, to add 'RTCOUT' to that bit description somewhere. We should also be adding links, whenever RTCOUT is mentioned, to jump to that bitfield.

 

Thanks for pointing this out!