Hello Johann, I am developing for the K60 which has the same timer set up as the KW2x. The solution that I decided to go for is to let the LPTMR run at 32768 Hz and let the hwtimer use that one. It will not allow for 1 µs precision, but at least it will be able to wake the MCU from STOP modes. I have not yet made a PR from my work, but you can see the current WIP state at https://github.com/gebart/RIOT, mulle branch.
Would there be any interest in merging the K60 and the KW2x peripherals into a single Kinetis port? See also some earlier threads regarding the Kinetis timers: http://lists.riot-os.org/pipermail/devel/2014-November/001426.html http://lists.riot-os.org/pipermail/devel/2014-October/001219.html http://lists.riot-os.org/pipermail/devel/2014-September/001086.html Best regards, Joakim Gebart Eistec AB www.eistec.se On 12/12/2014 11:14 AM, Johann Fischer wrote: > Hello RIOTers, > > I tried to implement a hwtimer for MKW2xDxxx and failed. > > The MCU has 4 downcounter PIT(Periodic Interrupt Timmer) 32-bit timers, > PITs can be cascaded so that timer[0] acts as prescaler for timer[1]. > PIT can be loaded with a start value. The timer will count down and > generate an interrupt at 0. Then the start value will be reloaded and > it will repeating. PITs can not run in low power modes. > Apart from the fact that it is a down counter, the timer do not work in > low power mode, and that bothers me. > > The MCU has also one Low-Power > Timer. This one is a upcounter 16-bit timer with compare register and > can be configured as as Free-Running Counter (reset on overflow not on > compare match). Also LPTMR can run in (very) low power modes. > I tried to implement the hwtimer with LPTMR. > The implementation divided (or multiply) the tick-values by 1000 and run > the timer with 1kHz. But this does not work reliable. > > There is also a RTC module, but it fits even less for the hwtimer. > > Ideas? > > Regards, > Johann Fischer > _______________________________________________ > devel mailing list > [email protected] > http://lists.riot-os.org/mailman/listinfo/devel _______________________________________________ devel mailing list [email protected] http://lists.riot-os.org/mailman/listinfo/devel
