Visit Jeremy's Blog.
Go Back > Forums > Linux Forums > Linux - Hardware > Linux - Embedded & Single-board computer
User Name
Linux - Embedded & Single-board computer This forum is for the discussion of Linux on both embedded devices and single-board computers (such as the Raspberry Pi, BeagleBoard and PandaBoard). Discussions involving Arduino, plug computers and other micro-controller like devices are also welcome.


  Search this Thread
Old 01-11-2008, 03:49 AM   #1
LQ Newbie
Registered: Dec 2007
Posts: 2

Rep: Reputation: 0
Question About RTC of PXA270


Please tell me about RTC of PXA270.

In my board, RTC Counter Register (RCNR) is cleared when I reset a CPU. (RCNR become zero).
So, "date" is always UNIX epoch when Linux is started.
RCNR is changed when I carry out "hwclock -w".
However, the other RTC registers do not change.
My question is as follows.

1. When a CPU was reset, is it right movement that RCNR is cleared?
2. if yes, where is "date" stored?


Last edited by xuhuang; 01-11-2008 at 03:50 AM.
Old 01-14-2008, 11:16 PM   #2
LQ Newbie
Registered: Dec 2007
Posts: 2

Original Poster
Rep: Reputation: 0
I'm sorry, I overlooked the following parts of PXA27x Processor Family Developer's Manual.

21.4 Operation
With the exception of the RTC Trim register, all registers
in the RTC controller are reset by hardware reset and
watchdog reset. The RTC Trim register (RTTR) is reset by the
hardware reset only.

The other resets(sleep-exit and GPIO) do not affect any of
the RTC controller blocks.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
PXA270 and it's framebuffer - 2700G OpenGL ES zelko Programming 2 04-23-2007 08:54 AM
LXer: Tiny Linux SBC steps up to PXA270 LXer Syndicated Linux News 0 03-30-2007 12:01 PM
Intel PXA270 development board help/newbie kev25 Linux - Newbie 2 01-20-2007 09:54 AM
LXer: Pxa270-based reference design runs Linux LXer Syndicated Linux News 0 07-12-2006 03:03 PM > Forums > Linux Forums > Linux - Hardware > Linux - Embedded & Single-board computer

All times are GMT -5. The time now is 05:43 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration