[ECOS] Frequency scaling on iPaq

[ECOS] Frequency scaling on iPaq

[Cristiano Ligieri Pereira]

Hi everybody,

I'm a little bit confused regarding how to scale the frequency on the
StrongARM SA1110 compaq ipaq platform. I'm trying to scale processor
frequency simply writting into the appropriate memory mapped register
(PPCR - Power Manager PLL Configuration Register). The values to be
written and the address of the register are described in the file
cyg/hal/hal_sa11x0.h (SA11X0_PWR_MGR_PLL_CONFIG is the register and the
values are SA11X0_CLOCK_SPEED_59_0_MHz, SA11X0_CLOCK_SPEED_73_7_MHz,
etc...).

The default processor operation seems to be at 206.4Mhz. If I try to scale
it down to 162.2 it seems to work fine but if I go down one more
level, which is 147.5, the system crashes. Looking at the file cpu-scale.c
of ipaqlinux source code I noticed that DRAM timing is related to the core
clock frequency and then DRAM timing properties have to be adjusted along
with the processor core frequency, otherwise DRAM becomes unusable and the
kernel crashes (that's is what is described in the source code). Or
alternatively the code responsible to scale the frequency has to be
executed at the ROM (Flash) memory.

Looking at the Intel StrongARM SA-1110 Microprocessor Developer's Manual
it is also described that the DRAM timing depends on the processor core
frequency.

I believe the same thing is happening with eCos/ipaq package since I'm
executing the code from the DRAM memory and I'm not adjusting any DRAM
timing parameter. Have anyone tried the same thing? Am I saying something
wrong? Did anyone have the same problem?

Thanks,
Cristiano.

------------------------------------------------------------ 
Cristiano Ligieri Pereira - http://www.ics.uci.edu/~cpereira

Re: [ECOS] Frequency scaling on iPaq

[Nicolas Pitre]

You are asking questions for which you already found all the answers
yourself.  What do you want exactly?


On Mon, 4 Jun 2001, Cristiano Ligieri Pereira wrote:

>
> Hi everybody,
>
> I'm a little bit confused regarding how to scale the frequency on the
> StrongARM SA1110 compaq ipaq platform. I'm trying to scale processor
> frequency simply writting into the appropriate memory mapped register
> (PPCR - Power Manager PLL Configuration Register). The values to be
> written and the address of the register are described in the file
> cyg/hal/hal_sa11x0.h (SA11X0_PWR_MGR_PLL_CONFIG is the register and the
> values are SA11X0_CLOCK_SPEED_59_0_MHz, SA11X0_CLOCK_SPEED_73_7_MHz,
> etc...).
>
> The default processor operation seems to be at 206.4Mhz. If I try to scale
> it down to 162.2 it seems to work fine but if I go down one more
> level, which is 147.5, the system crashes. Looking at the file cpu-scale.c
> of ipaqlinux source code I noticed that DRAM timing is related to the core
> clock frequency and then DRAM timing properties have to be adjusted along
> with the processor core frequency, otherwise DRAM becomes unusable and the
> kernel crashes (that's is what is described in the source code). Or
> alternatively the code responsible to scale the frequency has to be
> executed at the ROM (Flash) memory.
>
> Looking at the Intel StrongARM SA-1110 Microprocessor Developer's Manual
> it is also described that the DRAM timing depends on the processor core
> frequency.
>
> I believe the same thing is happening with eCos/ipaq package since I'm
> executing the code from the DRAM memory and I'm not adjusting any DRAM
> timing parameter. Have anyone tried the same thing? Am I saying something
> wrong? Did anyone have the same problem?
>
> Thanks,
> Cristiano.
>
> ------------------------------------------------------------
> Cristiano Ligieri Pereira - http://www.ics.uci.edu/~cpereira
>
>

[ECOS] Config Tool Under Linux

[Carlos Camargo]

Hi, i try to install configtool under linux, but i
don`t understand the diference betwen release and
debug option.

When i execute:

make -f $CONFIGTOOLDIR/Makefile WXDIR=$WXDIR
ECOSDIR=$ECOSDIR LEVEL=debug full

previously i define WXDIR ECOSDIR and CONFIGTOOLDIR


The following mesages appears:

checking for Tcl installation... configure: error:
unabe to locate Tcl config file tclConfig.sh

but, tclConfig.sh exist in my computer in /usr/lib, i
can fix a enviroment variable to fix it???


Can help me..

Thanks

Carlos Camargo


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Re: [ECOS] Frequency scaling on iPaq

[Cristiano Ligieri Pereira]

I want to know if anyone else had the same problem and whether the
solution was as I have just described.

Cristiano.

------------------------------------------------------------
Cristiano Ligieri Pereira - http://www.ics.uci.edu/~cpereira

On Tue, 5 Jun 2001, Nicolas Pitre wrote:

> 
> You are asking questions for which you already found all the answers
> yourself.  What do you want exactly?
> 
> 
> On Mon, 4 Jun 2001, Cristiano Ligieri Pereira wrote:
> 
> >
> > Hi everybody,
> >
> > I'm a little bit confused regarding how to scale the frequency on the
> > StrongARM SA1110 compaq ipaq platform. I'm trying to scale processor
> > frequency simply writting into the appropriate memory mapped register
> > (PPCR - Power Manager PLL Configuration Register). The values to be
> > written and the address of the register are described in the file
> > cyg/hal/hal_sa11x0.h (SA11X0_PWR_MGR_PLL_CONFIG is the register and the
> > values are SA11X0_CLOCK_SPEED_59_0_MHz, SA11X0_CLOCK_SPEED_73_7_MHz,
> > etc...).
> >
> > The default processor operation seems to be at 206.4Mhz. If I try to scale
> > it down to 162.2 it seems to work fine but if I go down one more
> > level, which is 147.5, the system crashes. Looking at the file cpu-scale.c
> > of ipaqlinux source code I noticed that DRAM timing is related to the core
> > clock frequency and then DRAM timing properties have to be adjusted along
> > with the processor core frequency, otherwise DRAM becomes unusable and the
> > kernel crashes (that's is what is described in the source code). Or
> > alternatively the code responsible to scale the frequency has to be
> > executed at the ROM (Flash) memory.
> >
> > Looking at the Intel StrongARM SA-1110 Microprocessor Developer's Manual
> > it is also described that the DRAM timing depends on the processor core
> > frequency.
> >
> > I believe the same thing is happening with eCos/ipaq package since I'm
> > executing the code from the DRAM memory and I'm not adjusting any DRAM
> > timing parameter. Have anyone tried the same thing? Am I saying something
> > wrong? Did anyone have the same problem?
> >
> > Thanks,
> > Cristiano.
> >
> > ------------------------------------------------------------
> > Cristiano Ligieri Pereira - http://www.ics.uci.edu/~cpereira
> >
> >
> 
> 

Re: [ECOS] Frequency scaling on iPaq

[Nicolas Pitre]

On Tue, 5 Jun 2001, Cristiano Ligieri Pereira wrote:

>
> I want to know if anyone else had the same problem and whether the
> solution was as I have just described.

We had that problem under Linux and the solution you described is correct.
Look at the Linux code for reference.  It works fine on iPAQ.

Note that changing the PLL must be done  for long term power saving.  Since
the PLL requires quite a delay to stabilize when it is changed you can't use
CPU speed reduction for things like the idle loop.


Nicolas

Re: [ECOS] Frequency scaling on iPaq

[Cristiano Ligieri Pereira]

have you tried it on eCos? I'm doing exacly the same things that are done
in the change_clock_speed() function execpt the function call to
recalibrate_delay(void) since it deals with linux global variables.

Now the system frezzes and the LCD display shows nothing when I try to    
scale lower than 162Mhz. Should I calibrate the FLASH timings as 
well? Although it's not done in the linux source code.

Thanks,
Cristiano.


------------------------------------------------------------
Cristiano Ligieri Pereira - http://www.ics.uci.edu/~cpereira

On Tue, 5 Jun 2001, Nicolas Pitre wrote:
> 
> We had that problem under Linux and the solution you described is correct.
> Look at the Linux code for reference.  It works fine on iPAQ.
> 
> Note that changing the PLL must be done  for long term power saving.  Since
> the PLL requires quite a delay to stabilize when it is changed you can't use
> CPU speed reduction for things like the idle loop.
> 
> 
> Nicolas
> 
> 

Re: [ECOS] Frequency scaling on iPaq

[Cristiano Ligieri Pereira]

I'm talking about the cpu-scale.c linux file, which is the one responsible
to scale the frequency.

------------------------------------------------------------
Cristiano Ligieri Pereira - http://www.ics.uci.edu/~cpereira

On Wed, 6 Jun 2001, Cristiano Ligieri Pereira wrote:

> 
> have you tried it on eCos? I'm doing exacly the same things that are done
> in the change_clock_speed() function execpt the function call to
> recalibrate_delay(void) since it deals with linux global variables.
> 
> Now the system frezzes and the LCD display shows nothing when I try to    
> scale lower than 162Mhz. Should I calibrate the FLASH timings as 
> well? Although it's not done in the linux source code.
> 
> Thanks,
> Cristiano.
> 
> 
> ------------------------------------------------------------
> Cristiano Ligieri Pereira - http://www.ics.uci.edu/~cpereira
> 
> On Tue, 5 Jun 2001, Nicolas Pitre wrote:
> > 
> > We had that problem under Linux and the solution you described is correct.
> > Look at the Linux code for reference.  It works fine on iPAQ.
> > 
> > Note that changing the PLL must be done  for long term power saving.  Since
> > the PLL requires quite a delay to stabilize when it is changed you can't use
> > CPU speed reduction for things like the idle loop.
> > 
> > 
> > Nicolas
> > 
> > 
> 
> 

Re: [ECOS] Frequency scaling on iPaq

[Nicolas Pitre]

On Wed, 6 Jun 2001, Cristiano Ligieri Pereira wrote:

>
> have you tried it on eCos?

No.

> I'm doing exacly the same things that are done
> in the change_clock_speed() function execpt the function call to
> recalibrate_delay(void) since it deals with linux global variables.

Then it should work.  Be sure you adjust the ram timingsin the same order
i.e. whether you actually increase or decrease the clock frequency.
Double-checking the SDRAM parameters for each frequencies might be worth it
too.

> Now the system frezzes and the LCD display shows nothing when I try to
> scale lower than 162Mhz. Should I calibrate the FLASH timings as
> well? Although it's not done in the linux source code.

Normally it shouldn't matter if you slow down the flash access.  The LCD and
PCMCIA timings might have to be recalibrated as well.


Nicolas

Re: [ECOS] Config Tool Under Linux

[Julian Smart]

Hm, strange. Maybe try setting TCLHOME? OTOH I have tclConfig.sh in 
/usr/lib but don't need this variable to be set.

Sorry, I'm mystified...

Julian

At 10:09 AM 6/5/01 -0700, Carlos Camargo wrote:
>Hi, i try to install configtool under linux, but i
>don`t understand the diference betwen release and
>debug option.
>
>When i execute:
>
>make -f $CONFIGTOOLDIR/Makefile WXDIR=$WXDIR
>ECOSDIR=$ECOSDIR LEVEL=debug full
>
>previously i define WXDIR ECOSDIR and CONFIGTOOLDIR
>
>
>The following mesages appears:
>
>checking for Tcl installation... configure: error:
>unabe to locate Tcl config file tclConfig.sh
>
>but, tclConfig.sh exist in my computer in /usr/lib, i
>can fix a enviroment variable to fix it???
>
>
>Can help me..
>
>Thanks
>
>Carlos Camargo
>
>
>__________________________________________________
>Do You Yahoo!?
>Get personalized email addresses from Yahoo! Mail - only $35
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