Eric: >> Eric and Peter: Would you venture into setting SMCLK=DCO as the >> default for the new generation msp430 platforms? > > The current msp430 integration branch.... has this already set. At > least > for anything beyond the x1 family. I have to check what is done for the > telosb. > I'm pretty sure I left that alone because I didn't want to deal with the > backward compatability > issues and the chance that I would break something. Great! I wouldn't touch the telosb, though.
>> I just did a quick search for "new Alarm32khz32C()" and >> "Alarm32khz16C()", and indeed it appears that there is a huge pile of >> code (eyesIFX, tda5250, tkn154, lib/net/zigbee, etc.) that would break >> if there were only 3 physical (I mean non-virtualized) 32khz alarms >> available. I noticed though that the new z1/msp430x code uses >> virtualized alarms. > > Can you point me at what you were looking at in the z1/msp430x code? > I've collapsed most of the z1 code, been through their timer code, and > don't recall running into this. > So would like to understand what you are looking at. Sorry, I was wrong. I was misled by the fact that Peter Bigot checked in a MuxAlarm32khz16C, etc. into tos/lib/timer. In fact, the z1 uses non-virtualized 32khz alarms, as well. >> > But keep in mind: sourcing a Timer from DCO for us-timestamping >> > will prevent the MCU from sleeping (LPM3), at least during Rx; >> >> That's not an issue. We have a software implementation of VHT (virtual >> high res timer), so we can even run FTPS with microsecond precision >> without having to prevent the MCU from sleeping. > > Can you give me a pointer.... I'd really like to look at what your are > doing there. Take a look at tos\chips\msp430\timer\LocalTimeHybridMicroC.nc. Thomas Schmid has a paper on this technique (http://www.eecs.umich.edu/eecs/cse/honors/pdfs/SDS10.pdf), though they did it in hardware. >> I will put together a telos-specific code that allows for choosing >> compile time whether a) SMCLK should be DCO or DCO/4 (default), and b) >> selecting the timer configurations (timerB->32khz timerA->micro being >> the default). > > Why compile time? I would think given a platform configuration it should > just always be that way for the given platform. Certainly so for new platforms, but not for the telos. There's just too many applications that depend on the current cc2420 stack. So choosing the cc2420x stack must be a compile time option. Janos _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
