[beagleboard] RTC base address
sanju More
Hi, What is RTC register address? i want to enable RTC in u-boot? is it possible to enable RTC in u-boot. --Sanjeev |
Søren Steen Christensen
> is it possible to enable RTC in u-boot.
The RTC is in the TPS65950-chip, which you can access using the I2C-bus. Take care - It isn't battery-backed-up and thereby loosing it's state when the power is removed from the board...
You find information about its registers in the TRM for the TPS65950-chip (http://focus.ti.com/lit/ug/swcu050d/swcu050d.pdf) chapter 3...
Best regards - Good luck
Søren
sanju More
| I am writing values to RTC registers using imd(u-boot command), is it works? --Sanjeev --- On Tue, 5/5/09, Søren Steen Christensen <sorensch...@stofanet.dk> wrote: |
Søren Steen Christensen
works?
I would expect so - You might however need to control the mSecure signal
(see TRM and schematics for RevC) to be able to set the RTC value - I can't
remember for sure, but go ahead and give it a try...
Philip Balister
providing a battery backup as simple as connecting a suitable battery
(or capacitor), or is there more to it than this?
Philip
Søren Steen Christensen
> it
> > works?
> >
> > I would expect so - You might however need to control the mSecure
> signal
> > (see TRM and schematics for RevC) to be able to set the RTC value - I
> can't
> > remember for sure, but go ahead and give it a try...
>
> Speaking of the RTC, the Overo brings out the VBACKUP line. Is
> providing a battery backup as simple as connecting a suitable battery
> (or capacitor), or is there more to it than this?
>
> Philip
>
AFAIR - Connect the battery/capacitor and remember to enable charging using
a couple of I2C writes to TPS65950.
In order to be completely sure - Please double check the TRM and Data
Manual, but straight out of my mind I'm 99.9% confident it's that easy :-)
Søren
Sean D'Epagnier
rely on ntp. Does anyone have a software solution which can ensure
that we don't have future timestamp problems? I have been running
into this lately where I am compiling programs and "make" sometimes
gets confused and does the wrong thing. I just need to store the time
at shutdown and restore it at boot so I never have files with future
times.
Sean
Koen Kooi
Op 5 mei 2009 om 14:59 heeft "Sean D'Epagnier"
<geckos...@gmail.com> het volgende geschreven:\
>
> I just need to store the time
> at shutdown and restore it at boot
Preston Wilson
> Op 5 mei 2009 om 14:59 heeft "Sean D'Epagnier"
>
>
> > I just need to store the time
> > at shutdown and restore it at boot
>
> Angstrom does that by default
Create a shutdown script that does this
date +%m%d%H%M%Y > /etc/savedate
And in a startup script that does this
date `cat /etc/savedate`
The above is not tested. man date and man strftime will help in
correcting any problems.
-Preston
sanju More
| Hi, i did following commands at u-boot prompt. # imw 0x4A 0x0d 0x00 -- Stop RTC # imw 0x4A 0x00 0x36 -- Sec # imw 0x4A 0x01 0x54 -- min # imw 0x4A 0x02 0x90 # imw 0x4A 0x03 0x05 # imw 0x4A 0x04 0x09 # imw 0x4A 0x05 0x97 # imw 0x4A 0x0D 0x01 -- enable RTC After enabling i am reading the values by giving following command # imd 0x4A 0x00 10 But the values are not changing. i want to know is what i am doing correct? did i missed something. --Sanjeev --- On Tue, 5/5/09, Preston Wilson <rpwil...@gmail.com> wrote: |
|
Søren Steen Christensen
> # imw 0x4A 0x0d 0x00 -- Stop RTC
> # imw 0x4A 0x00 0x36 -- Sec
> # imw 0x4A 0x01 0x54 -- min
> # imw 0x4A 0x02 0x90
> # imw 0x4A 0x03 0x05
> # imw 0x4A 0x04 0x09
> # imw 0x4A 0x05 0x97
> # imw 0x4A 0x0D 0x01 -- enable RTC
>
> After enabling i am reading the values by giving following command
>
> # imd 0x4A 0x00 10
> But the values are not changing.
> i want to know is what i am doing correct? did i missed something.
Did you check the information in the TPS65950 TRM table 3.21 with respect to
the mSecure line?
Which board revision do you have B or C? You can control the state of the
mSecure line on Rev C, but not on Rev B AFAIR. I can't remember if it's
supposed to be high or low in order to alter the RTC...
Gerald Coley
Guylhem Aznar
IMHO it would be interesting to have the restore feature done by uboot
if an environment variable like lastknownrtctime exist
Keep saving the time in shutdown somewhere it can be accessed by uboot
(like with setenv), but let it be loaded automagically by uboot if the
parameter is present.
That'd really make the feature distribution independant. I really
prefer avoiding tweaking boot scripts- because then you must make sure
it's done before the fsck, in ro, etc.
On Tue, May 5, 2009 at 09:21, Preston Wilson <rpwil...@gmail.com> wrote:
> Create a shutdown script that does this
> date +%m%d%H%M%Y > /etc/savedate
--
Dr. Guylhem Aznar, MD PhD
Unité d'Analyse Médico-Économique
Service de Santé Publique et d'Économie de la Santé
Pôle SPSSR
CHU de Fort de France
BP 632
97261 Fort De France Cedex
Martinique, France
Tel : 05 96 55 23 47
Fax : 05 96 75 84 57
Søren Steen Christensen
> it will have an actual battery already soldered in.
When will Rev C3 be available - I expect(ed) this to be in the *far* future?
Søren
Gerald Coley
Gerald
Søren Steen Christensen
Cool - I will then wait getting my new Rev C board – Other new hidden features? J
Søren
From:
beagl...@googlegroups.com [mailto:beagl...@googlegroups.com] On Behalf
Of Gerald Coley
Sent: Wednesday, May 06, 2009 6:58 PM
To: beagl...@googlegroups.com
Subject: [beagleboard] Re: RTC base address
Far has many definitions. In this case far would meean we start shipping in a couple of weeks.
Gerald
Søren
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