LPC MicrocontrollersのトピックLPC11U68 RTC configuration

LPC11U68 RTC configuration

lpcware — Wed, 15 Jun 2016 19:40:52 GMT

Content originally posted in LPCWare by mattiad on Mon Sep 08 13:24:47 MST 2014
Hi,

For the first time I'm using an LPC11U68 microprocessor.
It's not clear for me if, in order to obtain an Real Time Clock, some external components are necessary (crystal and capacitors at pins RTCXIN and RTCXOUT) or the microprocessor has a complete internal generato for this purpose.
Can anybody help me?

Thanks in advance!

Mattia

Re: LPC11U68 RTC configuration

lpcware — Wed, 15 Jun 2016 19:40:53 GMT

Content originally posted in LPCWare by LabRat on Mon Sep 08 13:39:05 MST 2014
Hardware: RTC Hardware is described in schematic of LPCXpresso LPC11U68:

http://www.embeddedartists.com/products/lpcxpresso/lpc11U68_xpr.php

Software: LPCOpen should include a RTC sample:

http://www.lpcware.com/content/nxpfile/lpcopen-software-development-platform-lpc11xx-packages-0

Re: LPC11U68 RTC configuration

lpcware — Wed, 15 Jun 2016 19:40:54 GMT

Content originally posted in LPCWare by mattiad on Mon Sep 08 14:22:01 MST 2014
Thank you,

so you can confirm me that the crystal is necessary? This is what I suppose.

Re: LPC11U68 RTC configuration

lpcware — Wed, 15 Jun 2016 19:40:55 GMT

Content originally posted in LPCWare by LabRat on Mon Sep 08 14:44:22 MST 2014
Yes, as described in Datasheet and UM10732:

Quote:
8.22 Real-Time Clock (RTC)
The RTC resides in a separate always-on voltage domain with battery back-up. The RTC uses an[color=#f00] independent oscillator[/color], also located in the always-on voltage domain.

Re: LPC11U68 RTC configuration

lpcware — Wed, 15 Jun 2016 19:40:55 GMT

Content originally posted in LPCWare by mattiad on Tue Sep 09 12:03:33 MST 2014
Thank you very much!
Question Solved

Re: LPC11U68 RTC configuration

lpcware — Wed, 15 Jun 2016 19:40:56 GMT

Content originally posted in LPCWare by nxp_apps on Fri Sep 12 14:45:17 MST 2014
Hi,

Please also refer to the "RTC oscillator component selection" in the datasheet to select the correct capacitors for the 32 kHz crystal you will be using.

Thanks.

nxp support

Re: LPC11U68 RTC configuration

lpcware — Wed, 15 Jun 2016 19:40:57 GMT

Content originally posted in LPCWare by dariush_abbasi868 on Mon Jun 29 01:12:23 MST 2015
Hi,
In LPCOPEN sample code there isn't any clear sample to read hour and minute and ... for lpc11e68 .
Is it has LPC_RTC->SEC or somthing like that ?