As an FYI: Tmote Sky does have Rosc see http://www.moteiv.com/products/docs/tmote-sky-datasheet.pdf
TelosB (sold by others) does *not* have Rosc see http://www.tinyos.net/hardware/telos/telos-revb-2004-09-27.pdf Note that you have to enable Rosc. In Boomerang, this is done by defining MSP430_USE_ROSC_8MHZ. There is no equivalent functionality in TinyOS 2.x. Add the following to your Makefile when compiling with Boomerang: CFLAGS += -DMSP430_USE_ROSC_8MHZ -Joe On 2/16/07, Steve McKown <[EMAIL PROTECTED]> wrote:
On Friday 16 February 2007 11:26, Szymon Fedor wrote: > Thanks Steve. That is what I did. I copied the Msp430ClockP.nc into the > application directory and changed the line setting the BCSCTL2 register and > I set the constant TARGET_DCO_KHZ = 8192. It doesn't change the application > execution time. I know this works for clock rates of 1MHz, 2MHz and 4MHz. I can't honestly recall if I ever tried 8MHz. If it doesn't work, then perhaps there is a problem with the calibration routines. I think the code uses TimerA, so its frequency might be important. Sorry, I haven't looked at this in quite a while... > Are you sure about the utility of the Rosc? I still think > the external Rosc can increase the CPU clock. The msp430f1116 data sheet > states that DCO frequency is higher with DCOR=1 in comparison to the > configuration with DCOR=0 (page 37: DCO when using ROSC). Well, yes. If the value of the external Rosc is different from the internal value, then the fundamental frequency from which the DCO clock is derived would be different. But the msp430 can reach its full range of valid DCO clock rates without the external resistor. The external resistor option was added as a mechanism to allow designs to improve upon the DCO's notoriously bad clock drift. > I also tried to set the DCO to the maximal possible frequency (I used the > set_dco_calib(int calib) function from the Msp430ClockP.nc ) and still the > time of running the code does not change. Any other suggestions? > > regards, > Szymon > ----- Original Message ----- > From: "Steve McKown" <[EMAIL PROTECTED]> > To: <tinyos-help@millennium.berkeley.edu> > Cc: "Szymon Fedor" <[EMAIL PROTECTED]> > Sent: Thursday, February 15, 2007 10:37 PM > Subject: Re: [Tinyos-help] Tmote CPU clock speed > > > HI Syzmon, > > > > On Thursday 15 February 2007 15:07, Szymon Fedor wrote: > > > Does anyone know how to increase the default speed of CPU clock in > > Tmote? I > > > > tried to enable the external Rosc by changing the Msp430ClockP.nc file > > > > > > BCSCTL2 = DIVS1 | DCOR; > > > > > > and the time of executing some code (long "for loop") doesn't change in > > > comparison to the default configuration. I am using the new Tmotes > > > which have Rosc. > > > > The DCOR only tells the msp430 that an external DCO oscillator resistor > > is present. The external resistor can improve the accuracy of the DCO, > > but isn't really involved in setting the clock speed. > > > > If you are using tos2, the clock speed is set in Msp430ClockP.nc > > (probably within /opt/tinyos-2.x/tos/chips/msp430/timer, depending on > > installation). Check out busyCalibrateDco() and note the enum > > TARGET_DCO_KHZ. There > > might > > > be side effects to deal with. For example, defaultInitTimerA() should be > > changed so that SMCLK stays at 1MHz because other components assume it > > is. > > > > Perhaps you know this trick already. You can copy this file to your > > project > > > directory (the directory you are in when you type "make tmote"). The > > local > > > copy of the file will take precedence over the one > > under /opt/tinyos-2.x/tos/chips/msp430/timer. > > > > Have fun, > > Steve > > _______________________________________________ > Tinyos-help mailing list > Tinyos-help@Millennium.Berkeley.EDU > https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > !DSPAM:45d60008301041527717022! _______________________________________________ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
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