[Tinyos-help] atomic sections in HplMsp430GpioC and BusyWaitMicroC

[Michiel Konstapel]

If you wrap the whole sequence in an atomic block, it'll be collapsed
into a single atomic section. That should lower the total time
significantly, but you'll have one larger time window in which
interrupts won't be processed, instead of several short ones. I don't
know if that'll cause problems elsewhere (but it seems to work fine for
my software SPI code).

Michiel

 

From: tinyos-help-bounces at millennium.berkeley.edu
[mailto:tinyos-help-bounces at millennium.berkeley.edu] On Behalf Of Jacob
Sorber
Sent: woensdag 25 maart 2009 21:58
To: Tinyos-Help Help
Subject: [Tinyos-help] atomic sections in HplMsp430GpioC and
BusyWaitMicroC

 

I'm porting a driver for a OneWire bus from tinyos 1.x over to tinyos
2.1 and I'm having some trouble with delays introduced by atomic
sections around every clr/set/makeinput/makeoutput.  Making these calls
atomic is costing me around 10us per call.  The BusyWaitMicroC component
basically does the same thing.  So basically this sequence...


call GeneralIO.makeOutput();
call GeneralIO.clr();
call BusyWait.wait(5);
call GeneralIO.makeInput();
call BusyWait.wait(5);

...takes 50-100us instead of 10-15us.  I can fix this by removing the
atomic sections, but I'm a little worried that I'm going to break
something else.  Is there a "proper" way to do this?  I could just make
an "non-atomic" version of these components and wrap them in larger
atomic sections, but I would rather not if someone has solved this
problem already.

Thanks,
Jacob

-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.millennium.berkeley.edu/pipermail/tinyos-help/attachments/20090326/9c013f5a/attachment.htm